Guest post by Ira Glickstein
Albert Einstein was a great theoretical physicist, with all the requisite mathematical tools. However, he rejected purely mathematical abstraction and resorted to physical analogy for his most basic insights. For example, he imagined a man in a closed elevator being transported to space far from any external mass and then subjected to accelerating speeds. That man could not tell the difference between gravity on Earth and acceleration in space, thus, concluded Einstein, gravity and acceleration are equivalent, which is the cornerstone of his theory of relativity. Einstein never fully bought into the mainstream interpretation of quantum mechanics that he and others have called quantum weirdness and spooky action at a distance.
So, if some Watts Up With That? readers have trouble accepting the atmospheric “greenhouse” effect because of the lack of a good physical analogy, you are in fine company.
For example, in the discussion following Willis Eschenbach’s excellent People Living in Glass Planets, a commenter “PJP”, challenged the atmospheric “greenhouse” effect:
“The incoming energy (from the sun) you express in w/m^2, lets simplify it even more and say that energy is delivered in truckloads. Lets say we get 2 truckloads per hour. … when we come to your semi-transparent shell [representing greenhouse gases (GHG) in the atmosphere], you are still getting two truckloads per hour, but you say that these two truckloads are delivered to both the earth and to the shell — that makes 4 truckloads/hr. Where did the extra two truckloads come from?”
In that thread, I posted a comment with an analogy of truckloads of orange juice, representing short-wave radiation from Sun to Earth, and truckloads of blueberry juice, representing longwave radiation between Earth and the Atmosphere and back out to Space. A later commenter, “davidmhoffer” said “Ira, That was a brilliant explanation. …”
This Post is a further elaboration of my physical analogy, using a pitching machine and yellow and purple balls in place of the truckfulls of juice.
Graphic 1 shows the initial conditions. The Sun is a ball pitching machine that, when we turn it on, will throw a steady stream of yellow balls towards the tray of a weight scale, which represents the Earth. The reading on the scale is analogized to “temperature” and, with the Sun turned off, reads “0” arbitrary units.
TURN ON THE “SUN”
Graphic 2 shows what happens when the Sun is turned on and there are no GHG in the Atmosphere. The stream of yellow balls impact the tray atop the weight scale and compress the springs within the well-damped scale until equilibrium is reached. The scale reads “1”. This is analogous to the temperature the Earth would reach in the absence of GHG.
The balls bounce off the tray and, for illustrative purposes, turn purple in color. This is my way of showing that Sun radiative energy is mostly in the “shortwave” visible and near-visible region (about 0.3μ to 1μ) and that radiative energy from the warmed Earth is mostly in the “longwave” infrared region (about 6μ to 20μ). The Greek letter “μ” (mu) stands for a unit of length called the “micron” which is a millionth of a meter.
Since, at this stage of my physical analogy, there are no GHG in the Atmosphere, the purple balls go off into Space where they are not heard from again. You can assume the balls simply “bounce” off like reflected light in a mirror, but, in the actual case, the energy in the visible and near-visible light from the Sun is absorbed and warms the Earth and then the Earth emits infrared radiation out towards Space. Although “bounce” is different from “absorb and re-emit” the net effect is the same in terms of energy transfer.
If we assume the balls and traytop are perfectly elastic, and if the well-damped scale does not move once the springs are compressed and equilibrium is reached, there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth.
ADD GHG TO THE “ATMOSPHERE”
Graphic 3 shows what happens when we introduce GHG into the Atmosphere. The yellow balls, representing shortwave radiation from the Sun to which GHG are transparent, whiz right through and impact the weight scale and push it down as before.
However, the purple balls, representing longwave radiation from the Earth, are intercepted by the Atmosphere. In my simplified physical analogy, the Atmosphere splits each purple ball in two, re-emiting one half-ball back towards the Earth and the other half-ball out to Space. Again, you can assume that half of the balls “bounce” off the Atmosphere back to Earth like reflected light from a half-silvered mirror and the other half pass through out towards Space. In the actual case, it is “absorb and re-emit half in each direction” but the net effect is the same in terms of energy transfer.
OK, here is the part where you should pay close attention. The purple half-balls that are re-emitted by the Atmosphere towards Earth impact the tray of the weight scale and press against the springs with about half the force of the original yellow balls. So, at this stage, when equilibrium is reached, the well-damped scale reads “1.5” arbitrary units.
But, we are not done yet. The purple half-balls are absorbed by the Earth, and re-emitted towards Space. Then they are re-absorbed by the Atmosphere and once again split into quarter-balls, half of which head back down to Earth and re-impact the weight scale. Now it reads “1.75”. As you can see, the purple balls continue to get split into ever smaller balls as they bounce back and forth and half head out to Space. The net effect on the weight scale is the sum of 1 (from the yellow balls) + 1/2 + 1/4 + 1/8 + 1/16 and so on (from the purple balls). That expression has a limit of “2”, which is approximately what the scale will read when equilibrium is reached.
Again, the well-damped scale does not move once the springs are compressed and equilibrium is reached, so there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth. But the “temperature” of the Earth, as analogized by the reading on the weight scale, has increased.
DOUBLE THE GHG IN THE “ATMOSPHERE”
Graphic 4 is the final step in my physical analogy. Let us double the GHG in the Atmosphere. (NOTE: I am assuming that the doubling includes ALL the GHG, most especially water vapor, and not simply CO2!) This is represented by putting a second layer of Atmosphere into the physical analogy.
The purple balls emitted towards Space by the first layer of the Atmosphere are intercepted by the second layer, where they are absorbed, and smaller balls are re-emited in each direction. The downward heading balls from the upper atmosphere are intercepted by the lower Atmosphere and half is re-emitted down towards the weight scale that represents Earth. Once again, they compress the springs in the weight scale increasing the reading a bit, and are re-emitted back up. The purple balls get halved and bounce around up and down between Earth and the two layers of the Atmosphere, further increasing the reading on the scale once equilibrium is reached.
Again, the well-damped scale does not move once the springs are compressed and equilibrium is reached, so there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth. But the “temperature” of the Earth, as analogized by the reading on the weight scale, has increased due to the doubling of GHG in the Atmosphere.
WHAT I LEFT OUT OF THE PHYSICAL ANALOGY
Any simplified analogy is, by its very nature, much less than the very complex situation it is meant to analogize. Here is some of what is left out:
- My purple balls are re-emitted in only two directions, either up or down. In the real world, longwave radiation is emitted in all directions, including sideways.
- My purple balls are all totally absorbed by the Atmosphere and re-emitted. In the real-world, a substantial amount of longwave radiation is re-emitted from the Earth and the Atmosphere in the 9μ to 12μ band where the Atmosphere is nearly-transparent. A substantial portion of the radiation from Earth and the Atmosphere thus passes through the Atmosphere to Space without interception.
- My physical analogy addresses only radiative energy transfer. In the real-world, energy transfer from the Sun to Earth and Earth to Space is purely radiative. However, the Earth transfers a considerable amount of energy to the Atmosphere via convection and conduction, in the form of winds, precipitation, thunderstorms, etc. These effects are absent from my analogy.
- I represent the Atmosphere as a single shell, when, in fact, it has many layers with lots of interaction between layers.
- I represent doubling of GHG as adding another shell, when, in fact, doubling of GHG, if it occured (and if it included not just CO2 but also a doubling of water vapor and other GHG) would increase the density of those gases in the Atmosphere and not necessarily increase its height significantly.
- In my analogy, all the energy from the Sun strikes and is absorbed by the Earth. In the real-world, up to a third of it is reflected back to Space from light-colored surfaces (albedo) such as snow, ice, clouds, and the white roof of Energy Secretary Chu’s home :^). If a moderately warmer Earth, due to increased GHG, evaporates more water vapor into the atmosphere, and if that causes more clouds to form, that could increase the Earth’s albedo to counteract a substantial portion of the additional warming.
I am sure WUWT readers will find other issues with my physical analogy. However, the point of this posting is to convince those WUWT readers, who, like Einstein, need a physical analogy before they will accept any mathematical abstraction, that the atmospheric “greenhouse” effect is indeed real, even though estimates of climate sensitivity to doubling of CO2 are most likely way over-estimated by the official climate Team. When I was an Electrical Engineering undergrad, I earned a well-deserved “D” in Fields and Waves because I could not create a physical analogy in my overly-anal mind of Maxwell’s equations or picture the “curl” or any of the other esoteric stuff in that course. Therefore, those WUWT readers who need a physical analogy are in great company – Einstein and Glickstein :^).
I plan to make additional postings in this series, addressing some implications of the 9μ to 12μ portion of the longwave radiation band where the Atmosphere is nearly-transparent, as well as other atmospheric “greenhouse” issues. I look forward to your comments!
Ira, thank you so much
You tried to help me with this on another post and I still couldn’t “see” it..
I hope you realize from now on, every time I eat an orange or blueberry………;-)
That’s an interesting way of expressing the idea.
human beings are very smart, they can take any piece of scientific knowledge and turn it into technology, so not has no one used the CO2 green house effect for anything? Why don’t we replace the vacuum in Dewer flasks with CO2? Why don’t we fill greenhouses with CO2? Why are not the wall spaces and pairs of glass panes in houses filled with CO2?
Why does no one used this CO2 ‘trick’ as a force for good?
On even numbered days, I believe this happens, but the effect is so small it cannot be measured. On odd days, I don’t believe this at all and think CO2 can only increase coupling to space (increase our cooling rate). However, on both odd and even days, I think whatever CO2 can do, a fraction of a second after the sun disappears over the horizon, it’s done. With little thermal mass, a small thermal time constant and lacking extreme temperatures (there are no Little Carbon Dioxide Suns), CO2 can have no significance. Cold rarefied gases measurably increase the earth’s surface temperature? No, sorry, I don’t buy it.
Excellent presentation.
I believe in the GHG effect, already! Fortunately, it keep us a lot warmer than we would otherwise be.
The policy issues are, what is the marginal effect of human GHG emissions, and is it worth trying to do something about it by restricting those emissions? The marginal effect seems to be overblown, it’s not clear whether or a little warming or the next ice age is the bigger problem, and restricting emissions might well be more expensive than any benefits.
But the GHG effect is a physical reality.
Since I’m turing into a cranky old man, I prefer to see schematics using the natural properties, not graphics of coloured spheres and scales etc. That is, readers seem to me to need “dumbing up” more than “dumbing down”. There are many incorect statements about the interaction of IR with gas molecules on many blogs. I don’t expect people to improve their comprehension from analogues much more than I think that sketches would convert them to brain surgeons. (I’ve worked with visible & IR lasers at various wavelengths, icluding CO2 lasers, and done imagery using FLIR devices, so I’m not speaking from conjecture).
Great! Well explained. Thanks, Ira.
That makes sense to me! Great explanation!
Nice explanation – but it won’t stop the people who want to believe that the greenhouse effect doesn’t exist…..
One other problem with the analogy is the sun only shines half the time. The radiation occurs all the time.
One word: AmeriFlux (weather stations that measure the various energy IR flux terms – beyond the usual temperature, wind speed and humidity)
The website: http://public.ornl.gov/ameriflux/dataproducts.shtml
Relevance to this post?
See immediately about 1/3 way down tallbrokes wordpress page here where there is described LWIR measurement data from an actual Ameriflux site with reference to WV, CO2 and cloud cover …
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Seeing as how the Earth is round, shouldn’t a little more than half of the IR radiation be going back to space during the splitting and re-emitting?
The model works for me, but the devils in the details, such as how much water vapor increase, clouds, thunderstorms, etc., which gets to feedbacks upon feedbacks…
One thing you need to change is the size of the balls are uniform at each step, and are reduced in size uniformly, but in the real world they will be of different but close sizes, i.e. a photon of IR hits a CO2 molecule that physically moving away from the Earth it’s wavelength will be stretched via doppler shift and loose energy to the CO2 molecule, which would carry less energy back down to the Earth and likewise the inverse will be true as well; possibly even predictably depending on whether the atmosphere was upwelling as in a low pressure system or down-welling as in a high pressure system. Now the wrong-sized ball don’t get absorbed and re-radiated and we start getting into statistic and quality of the bandpass filter in the atmosphere and complication and chaos.
This is very good, thank you. I’ve had the basic idea, but not as clear. This confirms that I wasn’t way off in how I viewed it, and also helped clarify the concept some.
However, I have one (quite possibly stupid) question. When you double the GHGs, you do so by putting up two layers. In reality, of course, it would just be one layer that had more GHG. Does this make a difference in the effect?
Does that represent actual energy “lagging”? Temperature is a function of many things, and the same amount of energy applied to equal low-specific heat and a high-specific heat masses will result in far different temperatures (higher and lower, respectively).
Thank you for a clear and comprehensible writeup.
Afaik, the existence of the greenhouse effect is generally accepted.
The devil, as usual, is in the details.
First, the predominant greenhouse gas is water vapor, with CO2 a bit player. So the focus on CO2 seems questionable, even recognizing that CO2 does not freeze out like water vapor.
Second, the effect of successive doublings of any GHG declines to an asymptote, maxing out with a completely closed spectrum at the absorbed frequencies.
Third, the earth has a very dynamic and turbulent atmosphere, whose dissipative mechanisms are not well categorized.
These factors make it challenging to estimate the impact of increases in GHGs.
However, it does seem clear from the earths historical and geological record that there is a very powerful tendency to equilibrium in the system, that exponentials such as the more extreme IPCC projections are unlikely. Of course, that record also shows very abrupt climate fluctuations, taking place within a decade or possibly much less. A plausible theory elucidating those swings would be very useful, but they do not appear correlated with GHGs.
Assuming the second layer also reflects half the balls downward (and lets the other half pass through into space), if you calculate the infinite sum, I think you’ll find the “2+” for the 2-layer model comes out to 3.
What is wrong is that at every place in the atmosphere greenhouse gases are absorbing part of the IR. At every place, a little less than half goes back to earth, and rest goes out to space. A little less than half, since the Earth is a sphere.
IR going back down is likely to be re-absorbed & sent back out. It doesn’t matter how much CO2 you have, you can’t send back more than half the IR coming up from the Earth’s surface. Think about it.
It doesn’t matter how many times IR is absorbed & re-emitted, it cannot change the basic fact that never more than half can be sent back.
So once we reach that point, (and think we have) there can be no increase in the greenhouse effect.
Also worth reading as a greenhouse backgrounder is Steven Milloy’s write-up at JunkScience.com:
http://www.junkscience.com/Greenhouse/
Einstein, gravity and acceleration are equivalent, which is the cornerstone of his theory of relativity.
Einstein never knew that the planet was slowing when he created this theory or knew that the planet was faster in the past. So, the law of relativity fails UNLESS it is ADJUSTED to compensate for the faster speed and slower rate of objects falling on this planet. As the planet slow, objects get heavier due to less centrifugal force that compensates for ALL the energies exerting on the planet surface.
Well done.
Comment #5 (Left out section) could be more effective if a statement were made at drawing #3 to point out that the GHGs are not a layer but part of the mix of atmospheric gases. This would help dispel the incorrect notion of a shell or blanket that, like the glass of a greenhouse, shuts down the normal turning over of the lower atmosphere – the troposphere.
What happens in those parts of the world that don’t play baseball?
Al Gore would never accept this analogy, he has no balls!
Most of that short wave energy that goes into the oceans is transmitted to the atmosphere in the form of water vapor rather than radiation. That evaporation causes up drafts forming clouds that can carry that energy to the TOA where there is very little GHG to split your blue balls. The driving force for that convection is the difference in temperature between the sea surface and TOA. The rates of evaporation and condensation and freezing and thawing are controlling the rates heat is lost to space. CO2 follows these processes. Warming seas give off CO2. Cold clouds absorb it and carry it up and away or return it to the ocean in rain. CO2 is going along for the ride like a flee on an elephant. Think about the difference in magnitude between the heat of vaporization of water and the heat capacity of air.
My understanding is that all the energy supposedly absorbed by CO2 gets absorbed in the first 15m. If you double the amount of CO2 it gets absorbed in the first 7.5m, and then if you double it again it gets absorbed in the first 4.75m.
Since there is no real difference if the atmosphere is heated int he first 15m, 7.5m or 4.75m, CO2 makes ZERO difference. Unless of course you removed all Co2 fromt eh atmosphere – thereby killing all plants.
The infrared activity of the troposphere keeps tropospheric temperatures and surface temperatures cooler than they would be otherwise, not warmer. The infrared activity of the troposphere is what allows the troposphere to cool to space. That keeps surface temperatures cooler, not warmer.
If the troposphere was transparent to infrared energy and incapable of absorbing or emitting infrared energy, the troposphere would still be warmed via conduction with the planets surface, but it would not possess any means of ever cooling.
Under those conditions, tropospheric temperatures and surface temperatures would be very, very hot, day and night, year-round, forever.
Why on earth any rational person would believe that the infrared activity of the troposphere results in some kind of mystical, magical “greenhouse effect” that keeps surface temperatures warmer than they would be otherwise I cannot imagine. Perhaps it is some kind of leftover from the drug culture of the 1960’s or something, I don’t know.
Go figure.
This “explanation” makes no sense at all. Explain why more heat is not deflected back into space on entry IF the GHG is so good that it deflects heat FROM the Earth back to Earth.
Foe anyone not wishing to take Ira’s post on its merits, I suggest you stand before a large class of students and explain how the troposphere works. You have 2 hours. The next day return to those students and ask them to write out an explanation from only what is in their head. Let’s assume that class has only 80 students and they have 2 hours. When they are done you get to read all they have concocted and grade it. Come back and tell us how that works out.
All those balls would break the glass in a greenhouse.
Perhaps it would be better described as a “bounce house” effect?
Dunno.
One thing – all the wind/air currents blowing those balls around can’t be making the “bounce” any easier to predict or sometimes, perhaps, even discern. (OK, make that two things.)
@DocMartyn says:
February 20, 2011 at 5:13 pm
” Why don’t we fill greenhouses with CO2?”
Actually, it is common practice to increase the level of CO2 in large commercial greenhouses. It seems that it makes the crop in the greenhouse grow faster. Imagine that! Just use your favorite search engine to look for the use of CO2 in commercial green houses.
Ira:
Thanks for the opportunity to comment.
In my view, “the atmospheric greenhouse effect” is a misnomer and piece of propaganda. That there is an “effect” implies that there is an “efficient cause.” Tacking “the” onto the front of the phrase implies the uniqueness of the effect, given the efficient cause.
The “effect” is an increase in the equilibrium temperature at Earth’s surface. The “efficient cause” is an increase in the concentration of a greenhouse gas in the atmosphere. The equilibrium temperature is not an observable, making the claim of the alleged cause and effect relationship scientifically nonsensical.
To argue that a complex system can be reduced to cause and effect relationships is the logical error that is known as “reductionism.” In using the phrase “the atmospheric greenhouse effect” as though it were a fact, one makes this argument.
I get upset when I see “The greenhouse effect heats the earth because greenhouse gases absorb outgoing radiative energy and re-emit some of it back towards earth.” repeated. This is totally false. All the re-emitted radiation back to Earth represents is the RESULT of the Earth being heated by atmospheric greenhouse gases, NOT THE CAUSE. The atmospheric greenhouse gases act as a radiation partial insulator, but since the air transports the absorbed solar energy (by the atmosphere, ground and oceans) freely up by evaporation and convection, along with some net radiation, there is no heat trapping. The result of the radiation partial insulation is to raise the location of radiation to space to a high altitude rather than directly from the surface. The lapse rate caused by basic atmospheric dynamics (adiabatic wet lapse rate =-6.5 C/km) does the rest. The effective average location of outgoing radiation is about 5 km, so the lapse rate times 5 km=-33 C. Note that the higher ground and thus air temperature near the ground then cause the higher radiation levels. Also note it is ONLY the difference between up and down radiation that causes heat transfer, so both being bigger is just the RESULT not cause of heating.
According to the law of “Conservation of Momentum” your analogy is wrong!
After the initial absortion by the CO2 of the longwave radiation from the earth, most of the re-emitted longwave radiation should be emitted upward into space.
I see I did not address the point: does more CO2 increase the atmospheric greenhouse effect? The answer is yes, it slightly raises the location of outgoing radiation to space, and thus the lapse rate times the slight increase in altitude would raise the ground temperature. The main question is how much, and this is not clear. My best guess based on historical and recent data supports a raise of between 0.1 and o.5 C per doubling of CO2, with cloud negative feedback being a major controlling factor. This is much smaller than the CAGW estimates.
DocMartyn: You are correct, see my CO2 is Plant Food (Clean Coal, Say WATT?) for a potential way to use that CO2 to grow more food.
Brego,
The surface temperature would go to 255 C and the atmosphere would go to 255 C for an optically transparent atmosphere and a uniformly heated and cooled planet. However, since only one side is heated at a time and it rotated, and storage and transfer of energy from one location to another occurs, the problem is more complicated (as it is for Earth). It would NOT get hot.
Ira,
I think you’ve done an excellent job. The quibles about missing details (including your own list) are really insignificant. The main concept is intact, and in terms of providing an entry level explanation that can be easily visualized, I think it is excellent. Anyone with a reasonable understanding of your article ought to be able to walk up to a white board and explain it free hand to someone else in a matter of minutes. That’s the big piece we’re missing in the climate debate, widespread knowledge of the basics.
What I do think needs to be added doesn’t change the basic explanation at all, but I think a couple more graphics would really be beneficial, in fact answering some of the questions already posted in this thread.
The first regards what really happens as CO2 is added. The “shells” you illustrate help with the over all concept and provide for a basic approach from a math perspective as well. But I think once a person has that in their head, there ought to be one showing several examples of the actual path any given photon might take. For example, one going straight out to space, one going half way up then one quarter down then sideways… the net AVERAGE might be reasonably well represented by the concept of shells, but in reality there’s gadzillions of photons travelling at the speed of light and any one can change from any direction to any direction at any point in the atmosphere.
The next one I don’t have such a good handle on, but it needs both your shell explanation and the randomness of the photon paths explained first. How does one illustrate both those concepts at once, and in the gadzillions? I tried to create a graphic once but never finished it. My idea was to show the photons in the atmosphere as a shaded gradient. The gradient would be darkest at the bottom where the LW photons originate, and lightest at the top. BUT there would also be a darke fuzzy stripe somewhere in the middle. Since we’re trying to understand both the possible paths a photon might take to leave the atmosphere AND how the concentration at any given point changes, the dark stripe in the middle would represent that area of the atmosphere where downward bound LW and upward bound LW have a peak concentration.
From there is starts to be a lot easier to answer a lot of questions. Like someone;s question above about all the LW being absorbed within a certain distance, so what difference does it make? Another comment I hear a lot pertains to water vapour being so much stronger and absorber of LW that the CO2 doesn’t matter. You can show that it does by illustrating water vapour as being very “thick” at the bottom of the graph and very “thin” at the top because water vapour declines with temperature which declines with altitude. So CO2 is nearly insignicant close to ocean surface, but increases in signicance with both altitute and latitude.
No such thing. You cannot “back-radiate”, therefore, you cannot have a “greenhouse effect”
Gives me a better understanding of the conceptual difference between energy and temperature: how in the presence of the same amount of energy, an increase in GHG raises the temperature. Well done. Much appreciated…
CCR
Sorry Ken, but, although the nighttime Earth is cooler than it is in daytime, it remains warm enough to continue emitting longwave radiation. If not for the GHGs in the atmosphere (not just CO2 but also water vapor and other GHGs) it would be a heck of a lot cooler at night and, over the entire day and year, the Earth would be too cold to support life. Those are the facts. Please do not allow the distortions of the facts about CO2 sensitivity and the temperature record by the official climate Team lead to an equal and opposite reaction in the wrong direction.
Oh Ira, no look what you have done? You started the ball rolling, that’s what you have done. ☺ I’ve been waiting for someone for a long time to get that same visual. I’m terrible at art but your the man! And up from I don’t seem to be able to write very smooth and congenial but it is all meant that way all from a small injury from years ago, got my words but not my mind thank heaven!
Hope this post lingers long enough to discuss. Think after reading this we might.
I for one don’t need the drawing, I’ve had that very thing in my mind, but I do need it for others to see the complete picture placed in neat graphics so everyone can follow in step. By the way, fantastic graphics. I’ve been scanned.
Some additions/factors on your six points:
1. ½ up, ½ down — By the end of your series I sure hope you will cover the curvature of the Earth for this is the topic, this division is not real by 1%-2%. This correction is strictly geometric being a sphere and I have raised that in comments at least three times here in the past month’s and no one seems to get it or at least no one comments one way or the other. That factor favoring upward is enough alone to be Trenberth’s “missing energy” thought it probably isn’t per se.
2. The radiative window — Ok with that.
3. Thermals & evapo-transpiration — Ok with that for all of that energy ends up in the atmosphere just as if it had been radiated upward and absorbed high above so no real difference when only speaking of radiation.
4. Shells — Really it integrates as an infinite number of shells.
5. Doubling & H2O — I’ve got a problem here. That feedback to H2O is still up in the air and even though I feel it’s negative could you just set it for a while at a mean of 2½ % (Wikipedia says 1%-4% so I’m pick the middle, you might want some other) till the very last possible correction to your sequels? Please?
At that two and one-half percent concentration in the lower troposphere works out to be 62 water vapor molecules for each carbon dioxide molecule.
6. Albedo & reflection — Once again, could any possible cloud corrections wait till the end? Please?
However Ira, there is one huge error here on graphic two.
You can’t have double layers the way you drew it. Your first drawing is near perfect because ½ purple goes down, ½ purple goes up, same for ¼ and so on. Perfectly symmetrical. As should be.
But then you do what all AGWers would love to do but it violates pure integration logic, you add a new layer only on the top so look what is going up… always ½ of what goes down. That is you then have ½ down and ¼ up, ¼ down 1/8 up, and so on. You add more layers and quickly there is basically NO energy going up, all down. Do you see that?
Yes the atmosphere is an infinite number of layers but it really should be drawn that way on you very first graphic. But that is quite impossible right? So we are back to your imagination a bit.
Then what really happens when you double the CO2? You have double the molecules that *can* absorb but you have to replace each purple by two with ½ the energy. Double the balls but half their size. Conservation of incoming energy. Now that is correct. You see we have NOT increased the energy from the sun, we have only made it so each CO2 will only have ½ the energy it absorbs compared to the first example but the overall process is identical. Best to view the balls as some picked groups of photons, not individual ones. See that?
That is really what is buried in the words of Miskolczi’s work. I’m not propping him up but his paper did do one great thing, it measured the, how do I say it, average clear-sky Planck weighted IR optical thickness to a constant. That is basically the window. He places no cause on the recent century rise but it does become clear (took me months to see it) that doubling the carbon dioxide OR water vapor OR any other GHG will have no effect at all.
Once again, that is because solar input is rather constant and the energy there is divided by the *available* molecules. If you half the molecules (half the concentration), each molecule will be double busy absorbing photons and 90% or so will thermalize, bi-directionally. If you double the GHG molecules (double the concentration) each molecule will be having it easy for it is working half as hard absorbing photons. Probably a better way to word it but that’s the best I can do. Can you see it yet?
No wonder we need simple graphics, Einstein was right again! This is my third attempt to have at least one person seated in physics to see this. ☺
The more time goes by the more quantum physics changes and go away from being what what Einstein didn’t like about it. It looks like Einsteins opinion of quantum physics just might have been right!
Frank, that is not a stupid question. If we doubled ALL GHGs (not just CO2 but also water vapor, etc.) the Atmosphere would not double in height as it does in my simplified analogy. It would mainly increase the density of GHGs in the Atmosphere. Many scientists who know this stuff far better than I have done the analysis and they all agree that successive increases have a logarithmic effect, which my physical analogy also has. That means that doubling GHGs will increase warming, but by successively smaller increments, even considering just the radiative effects alone. (In the real-world, of course, if warming leads to more water vapor and if that leads to more daytime clouds, possibly more precipitation and thunderstorms and so on, the additional warming will be reduced, but, there will still be some warming with increased GHGs).
A way to think about the logarithmic effect on radiative transmission is to imagine you have a very sunny window. So, you install sun curtains that block 80% of the sunlight coming in, so the sunlight coming in will be 20%. If you then add another layer of sun curtains, that will block 80% of that 20% so the sunlight coming in will be down to 4%. Yet another layer of curtains will block 80% of that 4% and only 0.8% will come in. Of course, GHGs in the Atmosphere are not exactly like sun curtains, and there are other effects that reduce GHG warming, but the idea is the same. Each additional increment of GHG causes less additional warming than the previous increment.
Good explanation – but only if the concentration of the greenhouse gas is vanishingly small so that it’s absorption of the infrared is near zero. Doubling of the gas concentration would essentially double the absorption. Things are not that simplistic when the absorption bands are nearly saturated, like CO2.
At about 300 ppm CO2 there is only enough room in the atmosphere for a total of 5% more absorption of infrared. That is THE physical limit of the atmosphere density & depth and those additional 5% blueinfraredenergyberries occurs at 1,000,000 ppm CO2, yeh 100% CO2. Okay, so I concede that figure 3 is representative of 300 – 400 ppm CO2.
In doubling CO2 from 300 to 600 ppm (I know were at nearly 400 ppm now but my 95% CO2 band saturation information is at 300 ppm) the additional blueIRenergyberries that must be added to figure 3 to give figure 4 is only 2.5% so figure 4 grossly exaggerates what doubling of CO2 would do. This means that the scale would only increase to 1.025, NOT 2. And looking at the quality of the scale, I doubt if an additional 0.025 could even be detected. It would be hidden in the uncertainty.
Finally, I see a number of commenters above are now raising the sphere factor!
It’s a good day! (but a long, long day today)
HaroldW, you may be right, but only if the downward balls from the upper Atmosphere layer in my physical analogy could fall directly on the Earth, without having to go through the lower Atmosphere layer. In my analogy, however, those balls have to go through the lower layer and only half of them will make it on the first shot. That is why I made the meter stop short of “3”.
The real-world situation is different, of course, because additional GHG increase density and don’t add another layer. Yet, the longwave radiation that happens to be emitted downward from the added GHG does have to pass through more dense GHGs so some of it will be absorbed and re-emitted upwards. If any WUWT reader actually knows, please tell us. advTHANKSance!
RayG, I think you are missing DocMartin’s point. He is not talking about inputting greenhouses with CO2 to help with plant growth, which everyone knows is common practice. Rather, is anyone putting CO2 in greenhouses to make them warmer?
FatBigot says:
February 20, 2011 at 6:21 pm
What happens in those parts of the world that don’t play baseball?
Soccer balls, footballs, hockey pucks, tidleywinks, marbles, snowballs, cow flops, etc. :^)
Denier/Skeptics dreamtime has arrived!
http://www.accuweather.com/video/793604479001/a-week-of-global-cooling.asp?channel=vbbastaj
LOL
Eric;
Hmmm … 2 empty greenhouses (no plants), one with atmospheric atmosphere, the other with, say 2,000ppm CO2 atmosphere. Insert thermometers, check periodically.
Ira I sympathize about “curl”. I remember when electromagnetic influences were introduced in physics with the ‘right-hand rule’; one of my classmates said quite loudly that “This doesn’t make sense!”. I looked at him, saw the thumb, index, and middle finger of his left hand extended, and gently corrected him…
Could you tell me what happens to the momentum of your purple balls that are re-directed towards earth. If one uses kinetic theory as an analogy, there is a momentum change of 2 units in this reversal of direction, and the net momentum of the system has increased by one unit (due to the recoil experienced by the emitting molecule). In kinetic theory this momentum change exerts a pressure on the walls of the container. Do CO2 molecules experience a pressure acting away from earth when they absorb a purple ball (or photon) moving away from earth and then re-direct it towards earth?
Shouldn’t we be able to observe the “darkening” of Earth in the IR spectrum from a satellite looking down? If the reflection into space is turned into heat on Earth, then there must be lower observed IR from space. Thus in addition to direct temperature observations, we should have direct IR observations which would correlate. Unless the phenomenon does not really exist — my bet.
DocMartyn says February 20, 2011 at 5:13 pm
We have smart glass coatings using the same principle that are far more effective. A better question is why do we keep water out.
The Sun energy coming in is in the visual and near-visual (shortwave) bands, where the Atmosphere is all but transparent. The absorption spectum for GHGs has a “window” for that light energy, so it whizzes right through, just the way a police car can buzz through a red light or stop sign in an emergency.
The Earth energy going out is in the far infrared (longwave) “heat” bands, where the Atmosphere is mostly not transparent. The absorption spectrum for GHGs is effective for that heat energy, so it has to stop, as you do for a red light or a stop sign.
The reason the Sun’s light energy is in the shortwave range is that it is something like what scientists call a “blackbody” at around 5500ºK, which is really hot. The reason the Earth’s radiation is in the longwave range is that the Earth is something like a “blackbody” at 210ºK to 310ºK, which is lot cooler than the Sun, fortunately for us living beings.
The reason GHGs act that way has to do with the atomic structure of their molecules. Water vapor (H2O) is by far the most effective GHG, covering much of the radiation spectrum, particularly about two-thirds of the spectrum where Earth outputs longwave radiation, but it has a convenient “window” for UV and visible light, and some infrared. Carbon dioxide (CO2) is mostly transparent to radiation, but it has a few absorption bands, the most important of which is around 12μ to 17μ, in the range where the Earth outputs longwave radiation. Other GHGs are oxygen (O2), ozone (O3), nitrous oxide (NO), and methane (CH4), but they have relatively narrow absorption bands in the range where the Earth outputs longwave radiation. The majority of the Atmosphere consists of Nitrogen (N) that is transparent to all radiation in the bands of interest. I hope this clears things up for you.
Those cold gases are a lot warmer than absolute zero which is the temperature of outer space.
Imagine, if you will, a layer of solid insulation on the outside of your house. The inner side of the insulation will be at the temperature of your living room. The outer side of the insulation will be at the outside temperature. The temperature within the insulation will be according to how close to the outside you measure. The closer you are to the outside, the colder it will be.
Nine tenths of the way through the insulation, it will be nearly as cold as it is outside. So, my question to you is: how is it that this very cold insulation manages to measurably increase the temperature in your living room?
(In this argument, you have to assume that your furnace is operating with a constant output rather than being controlled by the thermostat. Actually, the insulation merely decreases your fuel consumption.)
Dr Glickstein,
You seem to be equating energy to temperature. You are weighing all those balls of energy and getting a temperature reading. I give this analogy an F.
This is deceptive labeling and presentation.
It should be “ANALOGOUS TO [DAYTIME] SURFACE TEMPERATURE INCREASE CAUSED BY CO2”
For example, in keeping with the simplisic presentation:
Normal summer high temp in LA with no layer = 299 Kelvin + 0 CO2 degree (80 degrees Fahrenheit)
With 1 CO2 Layer:
Normal summer high temp in LA with one layer = 299 Kelvin + 1 CO2 degree (81.8 degrees Fahrenheit)
With 2 CO2 Layers
Normal summer high temp in LA with one layer = 299 Kelvin + 1.5 CO2 degrees (82.7 degrees Fahrenheit)
This would help the people that can actually tell the difference between 80 and 82.7 degrees while they are outside, during the day.
Deceptive graphic. Easy to [miss] understand. Pseudo-Science for the masses.
Eric @ #49
“. . . is anyone putting CO2 in greenhouses to make them warmer?”
See Ira’s comment at #45 with respect to the logarithmic effect. At the amounts used, say 800 to 1,000 you will get about all the warming there is to get. Even then the air as to be put in motion (small fan) or the heavier than oxygen CO2 will settle. A person could kneel down to clean up a mess on the floor and the air might not have enough O2. Bummer.
Very good article by Dr. Glickstein, within the stated limitations.
My favorite simplification of the so-called greenhouse efffect is still Willis Eschenbach’s “Steel Greenhouse” article from November 2009:
http://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/
Thanks David for your kind words, and, as I noted at the head of this Topic, your input in Willis Eschenback’s Topic was a key encouragement for me to make this posting. I intend to post more in this “greenhouse effect” series and, if you have any diagrams or ideas, feel free to email them to me at ira@techie.com. advTHANKS
You have made a graphical model of the so called Greenhouse Effect but is it a faithful model of the actual atmosphere with real world physics at work?
When you are discussing the real world, you don’t start from an arbitrary theory and dictate to the real world how it works. You start with the real world and DISCOVER how it works. The real world is what it is and it does not pay the slightest attention to what you think it is no matter what your credentials, the number of papers you have published, nor how many scientific societies you belong to.
I suggest you need to study the science of Thermodynamics in some significant detail before you create any more pretty pictures. That way you might have a chance of saying something worth listening to. As it is, any one of Aesop’s Fables is far more instructive about the real world than your presentation on this blog.
For awhile there I had numbered comments. A flaky system tonight. I tried to send the following and it blew Google Chrome off the desktop.
So, I’ll try again:
At 8:40 pm: That’s “the air has to be. . ”
Ira,
Drop the degree symbol on the kelvins, please.
Since IR radiation is a finite amount equal to the short wave energy reaching the earth, how much CO2 does it take to absorb/intercept/deplete all the IR in the narrow bands representing 15-20% of the spectrum. It’s like a greenhouse with 80% of the glass missing. Most non-scientists are misled by the impression (not corrected by the pro-wraming crowd) that CO2 acts in a linear fashion, with each additional amount (ppm) causing a commensurate amount of warming.
One may dispute the exact amount, but due to the efficiency of CO2 in absorbing IR radiation, and using Beer’s law, Professor James Barrante and others have calculated that half the available IR is absorbed by as little as 80 ppm. After that less and less IR is available as it is depleted logarithmically by additional CO2, until most all is gone by the time CO2 reaches 250-300 ppm. Little more warming can occur.
So, how can it be said, without decieving people, that ever increasing CO2 will cause more and more warming?
I hate to appear dumb but I don’t follow this.
The sun heats the earth – OK (warms). The earth then loses heat – (cools by radiation).
The CO2 (and water vapour etc.) gains heat and but can’t store it (except by transfer to O2 & N2 which are poor radiators) so must radiate.
But a colder surface can’t radiate to a hotter surface, so the earth and the CO2 have to be equal in temperature, so the minor difference (a purple ball) can bounce back and forth between them. If the earth warms, then there is no balance, so the atmosphere can’t radiate back to it, so the extra heat radiated from the earth and absorbed by the greenhouse gases must go elsewhere (e.g. convection) until such time as the atmosphere warms up to the new temperature.
But in this scheme the earth isn’t warmer because it emits everything it absorbs. And at the end of the day you’ve put 100 units of heat into the earth and a 100 units have left the earth. If the heat absorbed is boosted by your purple ball series, so too is the amount of heat radiated into space.
It seems to me that these radiative models are merely counting the same heat twice.
You might say that “extra” heat is stored in the atmosphere because it hasn’t radiated out yet, and may warm the earth slightly at night. But the heat capacity of the atmosphere is so much less than that of the earth, that any warming must be minimal before it all radiates out to space.
That is the second “F” I’ve received blogging here at WUWT. The lowest grade I ever got as an undergrad was that “D” in Fields and Waves I mentioned above, and, as a grad student, I got a couple “B” grades. So, I guess WUWT is tougher than college!
However, as a current adjunct prof at the University of Maryland University College, teaching an online grad course in System Engineering, I am sorry to have to give you an “F” for your failure to understand my physical analogy and recognize that I am NOT equating energy to temperature at all. Not good comprehension, particularly for a physics major :^).
It is not the weight (i.e., mass) of the balls that is being weighed because they bounce off the tray of the weight scale and do not stay around to help hold it down against the springs, it is the force of the balls that repeatedly pound on the tray and it is the repetition of the pounding by successive balls that keeps the springs compressed.
“Temperature” in my analogy is the displacement of the tray downward when the scale reaches equilibrium, with the force of the compressed springs exactly equalling the pounding force of the balls.
In the real-world, the energy input from the Sun warms the Earth until the radiation from the Earth exactly equals that coming in from the Sun. At that point, the temperature stabilizes. Got it?
Three important things missing here.
1) The purple ball shield is full of holes as CO2 can only absorb over a couple of narrow IR ranges. Thus, the efficiency falls drastically. The big argument would be how much this would impact the balance. In reality, its very small and likely undetectable in the changes we are seeing in CO2.
2) Beer’s Law is not addressed as the effect of warming plateaus as CO2 increases. It’s effect is 90-95% expended.
3) “doubling of GHG, if it occured ( . . . ) would increase the density of those gases in the Atmosphere and not necessarily increase its height significantly”
Zagoni and Miskolczi have shown quite elegantly that, as CO2 rises, absolute water in the upper troposphere decreases (already observed in real measurements). You cannot just add density to the atmosphere, something has to give. Here, it is water vapor that is replaced by an inferior heat-trapping gas, creating an atmosphere with less “greenhouse” effect. A tiny bit of cooling is in order.
I think you skipped over 2 major steps even in your simplified version. The first being that your initial premise does not start as a black body condition, the second add you add atmospheric variations your failing to absorb your initial source. This would be a reduction (in your simplified diagram) to .7 difference from initial non atmospheric to atmospheric variations.
In other words, its not a one way mirror.
Leonard Weinstein says:
February 20, 2011 at 7:11 pm
does more CO2 increase the atmospheric greenhouse effect? The answer is yes, it slightly raises the location of outgoing radiation to space…. The main question is how much, and this is not clear. My best guess based on historical and recent data supports a raise of between 0.1 and o.5 C per doubling of CO2, with cloud negative feedback being a major controlling factor. This is much smaller than the CAGW estimates.>>>
Leonard, your numbers may be closer than you think to the CAGW estimates. Buried in the fine print if IPCC AR4 is a note explaining that the temperature increases they arrive at from their models are calculated at the EFFECTIVE black body temperature of earth, NOT the surface temperature. They use (if I recall correctly) -20 C as the effective black body temperature rather that the +15 C usually quoted as the average surface temperature.
So… apply Stefan-Boltzman to the whole mess. They calculate doubling of CO2 = 3.7 w/m2 = +1 degree. But that’s at -20 C. Since the SB Law is that
Power in watts = constant times temperature in degrees Kelvin raised to the power of four
or
P=(5.76*10^-8)*T^4
One can then extrapolate their calculation to the surface temperature. Too tired to do math at the moment, but you get a lot smaller number at surface than you do at effective black body using the IPCC’s own science! .6 or around there.
Further, the use of 15 C as an average is VERY deceptive. If the night time low in a given area is 10 C, and the day time high is 20 C, does that mean that the average temperature of the day was 15 C? HIGHLY unlikely. But if by some miracle it was, you STILL can’t assign a temperature increase from CO2 that is meaningful. Back to Stefan-Boltzman again! The temperature increase from an additional 3.7 w/m2 will be smaller for the day time high than for the night time low. And summers don’t get much warmer, but winter lows become milder. And valleys dont get much warmer but the mountain tops next to them warm a bit more. And the poles warm more than the temperate zones and the tropics warm hardly at all.
If you break down NASA/GISS or HadCrut by latitude and season, you’ll see exactly what Stefan-Boltzman says.
As for the IPCC and doubling CO2 = +1 degree? Absolutely correct. And totaly meaningless.
Ira,
You should include the diminishing returns from each doubling in your analogy. This is an absolutely critical aspect of the greenhouse effect that is overlooked by the general population. Somehow it also seems to be overlooked by some climatologists (sigh). Maybe have the scale go from 1 to 1.5. Then to 1.75, then to 1.875, etc. Also it would be good to show how close to 100% absorption we are at.
Oh, one more detail that is also overlooked. The CO2 cannot radiate heat back toward the earth if the Earth’s temperature is warmer than the gas. It can only radiate heat in a direction that is colder (see Laws of Thermodynamics).
Kinda O/T. Snip of you must.
I’ve heard the elevator acceleration/gravity example given before but disagree with it due to remembering something from school. My teacher gave the example of a elevator in free fall (accelerating under gravity) towards the Earth. If you had 2 oranges which you placed a certain distance apart in falling with you in the elevator, they would move towards each other the closer to the planet you got due to tidal forces. (The oranges are drawn towards the gravitation centrepoint of the Earth and therefore if they could fall right to this centrepoint they would eventually touch each other). This is not true of a constantly accelerating elevator in free space.
“dt3 says:
February 20, 2011 at 7:03 pm
According to the law of “Conservation of Momentum” your analogy is wrong!
After the initial absorption by the CO2 of the longwave radiation from the earth, most of the re-emitted longwave radiation should be emitted upward into space.”
The momentum of a 15 micron wavelength radiation is 4.4 x 10^-29 kgm/s using p = hf/c. So it would change the speed of a CO2 molecule by 6 x 10^-4 m/s. This is totally negligible compared to the average speed of about 400 m/s for a CO2 molecule. Molecules go in all directions, but if the upward component increases by 6 x 10^-4 m/s, there is no reason why radiation cannot then be emitted in any direction without violating the law of Conservation of Momentum. To really change the speed of something via a photon, you would need something light like an electron. (See the Compton effect.)
Ira, thank you for an excellent and clear analogy that anyone could follow.
Etudiant said
“First, the predominant greenhouse gas is water vapor, with CO2 a bit player. So the focus on CO2 seems questionable, even recognizing that CO2 does not freeze out like water vapor.
Second, the effect of successive doublings of any GHG declines to an asymptote, maxing out with a completely closed spectrum at the absorbed frequencies.
Third, the earth has a very dynamic and turbulent atmosphere, whose dissipative mechanisms are not well categorized.
These factors make it challenging to estimate the impact of increases in GHGs.”
This is another excellent point.
There is just too many uncertainties ( I even quoted the IPCC just now 🙂 ) to be able to accurately estimate the amount of rising tempature due to GHG’s.
Myself and a friend of mine, (myself, a skeptic, and him, an believer in AGW) were having a conversation about this. I told him I didn’t believe that the small amount of CO2 in GHG’s, ( compared to Water Vapour, which has been estimated to be around 90% of GHG’s), could have such a high effect as the IPCC and others claim.
He responded by reminding me that a cold virus is a tiny organism, yet still able to do large damage to anyone who catches it, and similarly, CO2 works the same way.
I then argued if that analogy was completely accurate, then every single person ever exposed to the virus would catch it immediately, and experience the exact same amount of symptoms, hangtime of the cold, and so on. Yet it isnt. Some of us get sick, some dont. Some are healthier then others, some get sick from one cough nearby, and some seem to be as fit as a fiddle.
The fact is, there are just so many variables and uncertainties that we cant accurately admit that we know exactly how AGW works. Even the IPCC admits there is much they dont know.
Yet trillions of dollars are being allocated and millions of policy decisions are being made on it.
This is what I debate. My friend, in fact, did not have an answer.
P.S. I apologize if my description is overtly simplistic, physics were never my strong point. Feel free to point out any I may have made. 🙂
Dr. G.
With respect, as they say when they’re about to get stuck right in.
With respect, I cannot fault your simple analogy, with the exception of a couple of small quibbles:
(1) I presume in later episodes you will explain how clouds and water vapour and such like complicate your very clear exposition.
(2) How does you model explain the paleontological evidence that in times long gone, somtimes there was much more CO2 than a mere doubling would entail, yet temperature remained quite cool? At other times it was quite hot with low levels of CO2, while yet at other times, it was hot with high CO2 or cold with low CO2. Does you physical model explain all these as well. If not, WUWT?
that’s all for now.
Ira
Interesting approach. I always enjoy your posts.
As you tune this model, one factor should be considered along the lines of your number 6.
Since you are doubling all greenhouse gasses, I begin to loose confidence as to the validity of the model.
In reality if we double the water vapor would not the increased clouds significantly reduce the amount of energy that reaches the earth in the first place? And possibly cause cooling, as well as other impacts since a lot of things on earth depend on the sunshine energy, including trees etc.? Ideally the model needs to consider only doubling the CO2 which is more complex.
I have no trouble believing in the basic so called “greenhouse” effect as long as we admit the actual Physics may be different than an actual greenhouse.
For example we know that clouds significantly reduce the energy arriving here just by realizing the reduction in radiation reaching our body when a cloud suddenly passes over head on an otherwise sunny day. Unfortunately we cannot sense the effect of any change in CO2, partly because it does not filter out incoming sun energy and probably because it’s presence is so small Similarly I cannot personally detect the claim that CO2 radiates energy back to us either day or night.
Similarly we also know that on a cloudless night the earth cools down significantly faster and much more than when there are clouds overhead. Do we need any further evidence that at least clouds are a huge greenhouse gas? I can also believe that CO2 probably contributes, the question is how much and is it really significant given all the other factors like convection, wind, hurricanes, etc.
I tend to think that water vapor probably “rules” and Co2 may be a secondary effect at best even behind convection, evaporation, etc. Thr CAGW crowd woul be more credible it they acknowledged the fact the Water Vapor RULES.
Look forward to your improvement of the model.
“Ira Glickstein, PhD says:
February 20, 2011 at 7:53 pm
Yet, the longwave radiation that happens to be emitted downward from the added GHG does have to pass through more dense GHGs so some of it will be absorbed and re-emitted upwards. If any WUWT reader actually knows, please tell us. advTHANKSance!”
As you know of course, all gases, including GHGs are more dense as we go down. However I think the biggest thing that needs to be considered is that above the cloud layer, H2O has a very low concentration, so the CO2 above the clouds probably would “see” very little downward radiation hit Earth due to the sudden increase in H2O. At least this would be the case where absorption bands between CO2 and H2O overlap. Does this make sense and at least partly address your question?
Dr G.
On further reflection, I think that you have got the cart before the horse.
Step 1 (horse) you need to explain what the base line was, betore human CO2 emissions began – normal variability. Then you need to explain what has happened since and how much (if any is not due to normal variability).
Step 2 (cart) you should then examine all the competing explanations for what you have found in step 1 and state how well each explains any change that you have found. At that point and only at that point, you can introduce the particular physical laws that you have been explaining, as one possible explanation.
commieBob says February 20, 2011 at 8:29 pm
Nothing wrong with that per se. Now lets suppose some dodgy builder leaves out the vapour barrier on the inside and uses permeable insulation like normal rock wool. What do you suppose the temperature gradient through the insulation will look like now with normal household humidity levels if the dew point falls within the insulation (never mind the damage it will eventually do)?
Until someone shows me otherwise, I maintain water rules the thermosphere – it’s a heat pump running at half throttle with a hunting governor (clouds) and a massive heat sink under it. Please, why can’t these discussions for once address what happens radiatively at and above the thermopause? Earth does not present a solid radiative surface, it becomes increasingly rarefied and eventually physically stratified by molecular weight with elevation. Does simplistic application of radiative physics therefore still apply?
Dr. Glickstein, your thought experiment contains a serious error, and as such derives a false conclusion.
Although your thought experiment does fulfill the conservation of energy, it violates the conservation of momentum principle. Specifically, the blue slab that absorbs purple balls does so without moving. There is an action and no reaction, which means the momentum of the purple balls has been destroyed. However, the momentum of the half size balls that strike the ground is absorbed causing a force on the scales. You simply cannot destroy momentum in one instance and include momentum in another, this leads to a false conclusion.
To fix this thought experiment, you need to attach poles from the blue slab to the earth. When a large purple ball strikes the blue slab, tension is created in these poles. This tension creates a force that is exactly equal and opposite to the force generated by the half size balls striking the ground, i.e. Newton’s third Law. This means there will be no increase on the scales.
To leave out the reaction of the blue slab, to leave out the poles attaching the blue slab to the earth, and to leave out the counter balancing force on the earth means your conclusion that the scales will increase is false.
Dr. G.
First an apology – as usual my poor spelling and poor typing have again made my questions in my last two comments, even more difficult to understand than usual.
Second, it has just occurred to me that you have been talking about doubling GFC’s purely by increased human CO2 emissions.
Now that seems rather an odd way to approach the subject.
My understanding is that H2O represents between 0% and 4% of the atmosphere on different days and different places. In contrast CO2 and the other GFC’s make up only a tiny fraction of H2O’ contribution, bearing in mind that some of these have a more powerful effect that H2O.
Then you apply the logarithmetic effect and the fact the human emissions are only a part of total CO2 emissions. To that add the unknown (or at least un-agreed) reaction of H2O, clouds and so forth (positive and negative feedback). Well…
Perhaps the horse is not yet broken in, nor at all willing to drag your cart along.
(If you like my physical model of the task before you to simply explain the climate.)
An analogy, Ira Glickstein PhD, is supposed to ease the understanding of a problem, not make it more difficult.
You – and Willis Eschenbach when he starts ‘thought experimenting’ – just replace a relatively straightforward physical phenomenon with a complicated system with quite different physical properties. As a result you have now got many of your commentators worrying about elasticity and the various conservation laws – all of which has nothing to do with the ‘greenhouse effect’.
The greenhouse effect in essence is a simple, two step argument:
– CO2 (like a number of other gases) absorbs long wavelength IR. Any lab with a standard spectrometer can demonstrate this in under 30 minutes. What is to doubt?
– Such ‘greenhouse’ gases in the atmosphere therefore absorb long wavelength IR from the Earth’s surface. This heats them up, followed by all the consequent and well-known thermodynamic processes (radiation, etc.).
Now, the magnitude of this effect for particular greenhouse gases, the strata of the atmosphere that are affected and the resulting effects on our immensely complicated atmospheric system – that is the debate. To which, Ira Glickstein PhD, your analogy contributes nothing.
My response to Anthony’s appeal for suggestions for the future of WUWT: keep Ira Glickstein PhD in the cupboard under the stairs and don’t let him out without serious peer review. Publishing this kind of rubbish just exposes you to ridicule.
How does this re-heating of the earth by GHG, initially warmed by the same earth, go with the second law of Thermodynamics?
Just asking…
Greenhouse effect is simple indeed.
Ira, however, follows the wisdom: “Never choose a simple solution, if there is a way to make the things complex and beautiful”.
Great explanation for the day-time, but what happens when the sun goes down? What happens when the sun is cooler? (Why do greenhouses need heating in the winter?)
As with most analogies the compromise needed to create them looses a lot of the detail and the detail is key here.
“Why don’t we fill greenhouses with CO2?” – DocMartyn
We already fill greenhouses with the essential plant and planet nutrient CO2, and it works great growing us lots of yummy nutricioius food!
“For the majority of greenhouse crops, net photosynthesis increases as CO2 levels increase from 340–1,000 ppm (parts per million). Most crops show that for any given level of photosynthetically active radiation (PAR), increasing the CO2 level to 1,000 ppm will increase the photosynthesis by about 50% over ambient CO2 levels.
…
Carbon dioxide enters into the plant through the stomatal openings by the process of diffusion. Stomata are specialized cells located mainly on the underside of the leaves in the epidermal layer. The cells open and close allowing gas exchange to occur. The concentration of CO2 outside the leaf strongly influences the rate of CO2 uptake by the plant. The higher the CO2 concentration outside the leaf, the greater the uptake of CO2 by the plant. Light levels, leaf and ambient air temperatures, relative humidity, water stress and the CO2 and oxygen (O2) concentration in the air and the leaf, are many of the key factors that determine the opening and closing of the stomata.
Ambient CO2 level in outside air is about 340 ppm by volume. All plants grow well at this level but as CO2 levels are raised by 1,000 ppm photosynthesis increases proportionately resulting in more sugars and carbohydrates available for plant growth. Any actively growing crop in a tightly clad greenhouse with little or no ventilation can readily reduce the CO2 level during the day to as low as 200 ppm. The decrease in photosynthesis when CO2 level drops from 340 ppm to 200 ppm is similar to the increase when the CO2 levels are raised from 340 to about 1,300 ppm…. The level to which the CO2 concentration should be raised depends on the crop, light intensity, temperature, ventilation, stage of the crop growth and the economics of the crop. For most crops the saturation point will be reached at about 1,000–1,300 ppm under ideal circumstances.”
http://pathstoknowledge.wordpress.com/2011/02/20/real-benefits-of-an-enriched-co2-atmosphere/
Not bad at all Ira, you did a fairly good job of “people talk” to try and explain “the greenhouse effect”. It is really difficult to get through that the greenhouse effect has nothing to do with a greenhouse. Don’t worry about the Physics Major, he doesn’t understand “people talk”and wanted to show off his ignorance. Have a good one. pg
Ira, Possibly another 2 stupid questions. Could you firstly, explain to me why the temperature difference is significantly greater between day and night in the dry windless desert than it is in the humid stormy tropics and secondly, has the desert day/night temperature difference changed over time in accordance with climate modelling .
Ira, I think you alluded to it by the generic manner you addressed GHG’s versus singling out CO2 as one of many constituents (N2, O2, H2O, etc.) of the atmosphere but we need to get down to brass tacks here. Isn’t the real issue here the “density” of the atmosphere acting as an insulator that determines how much heat remains on a planetary body? If Venus’s atmosphere were pure Nitrogen versus CO2 with the same 90 bar pressure wouldn’t it be exactly as hot as it is now?
In fact, the only difference if there were any at all would be due to the physical property of specific heat of N2 (.18 Btu/lbsF) versus the specific heat of CO2 (.16 Btu/lbsF)? http://www.engineeringtoolbox.com/spesific-heat-capacity-gases-d_159.html Note: the specific heat given here is at 1 bar, not 90 bar but you get the point.
And wouldn’t that difference in specific heat be overcome by the wave lengths absorption ability of N2 versus CO2? http://www.iitap.iastate.edu/gccourse/forcing/images/image7.gif So if CO2 is not an absorber of UV or visable light but mostly of infrared then it stands to reason CO2 is only slowing down the rate of radition back to space just as Nitrogen is working to capture and hold it longer before radiating it off at infrared wave lengths. http://brneurosci.org/co2.html Given that there is vastly more N2 in the atmosphere than CO2, CO2 on a molecule per molecule basis can not in any way given its trace amount in any significant degree affect the temperature of the air much less get out of the error bar of a scientific calculation when dealing the heat balance of the planet.
So isn’t the whole issue really revolving around how dense the atmosphere is at any given time and has atmosphere during the latest warm spell been denser than say in the 1970s during that cold spell? As Anthony pointed out some time ago, when looking at the temperature profile of Vensus, where the atmospheric density reaches one bar in the atmospheric column, the temperature is nearly the same as Earth’s. Which in itself is remarkable given Vensus gets double the insolation of Earth due to it’s closer orbit to the Sun.
I am not a radiative physicist, so please bear with me. Infrared is energy of a certain wavelength, this hits a co2 molecule and is then instantly re-emitted, and the direction of emission is random, or does it re-emit at a 90 right angle to the incoming direction on a 360 degree plane? I assume the latter is correct, like light hitting a mirror?
Either way, it would then hit another particle below and bounce back only to hit others. There will be more particles to hit closer to the surface and less above so the energy isn’t trapped forever and eventually is emitted to space. The time is takes for the infrared energy to make its way through this tortuous path creates a back log of infrared energy which causes heat to be trapped. Correct?
My last question would be, does the net flow of energy have an effect on the direction of emission? A stone thrown into a still lake casts a perfect circle, but cast into a fast torrent the circle is emitted only forwards, due to the net flow of energy – does this analogy apply to the atmosphere, or does it not – as photons of energy cannot collide with each other but only interfere? Could upwards convection affect the emissive behavior of co2 and other GHG’s? or is it the otherway round, where the extra infrared energy results in increased upwards convection?
One issue I have with this sort of analogy is that 50% goes up and 50% comes back, I doubt its that simple in reality. Throw a stone in a still pond and its creates a circle, 50% one way, 50% the other, but if there is a net flow of water there is no longer a circle cast, and the stronger the flow of energy the more skewed it is on one direction, and when the flow of energy becomes supercritical, there circle is emitted in one direction only. I suspect this is more like the reality, as if two particles hit each other, one going upwards would have more speed and therefore anything emitted backwards is more likely to be ‘knocked’ back up then the other way around ( I hope I am explaining myself here!).
Any thoughts or views on this or is the net flow of energy to small an effect? I am interested to know if this has ever been considered, or is the greenhouse analogy of 50% one way and 50% the other a simplification to keep it simple? i.e. avoid difficult calculations that were not possible during the theories conception?
Graeme says (February 20, 2011 at 8:54 pm): “But a colder surface can’t radiate to a hotter surface…”
Ask yourself this question: As a sphere with a temperature, the earth radiates infrared energy in all directions. Does it radiate any of this energy at all in the direction of the sun, a much hotter body?
Sounds plausible until you realise that Atmospheric CO2 is not plentiful enough to have the stated effect.
Atmospheric CO2 = 0.034% Now try to imagine a box filled with one million smaller boxes. Now picture 390 boxes are CO2 molecules spaced evenly throughout the remaining 999.610 boxes. Now double the number of boxes to 780 and again imagine them spread evenly throughout the remaining 999210 boxes.
The few CO2 boxes within the larger box cannot have the proposed ability to both absorb, store and pass on all the solar radiation in the form of heat to different boxes each with their own particular absorption ranges which do not match the huge majority of boxes surrounding the CO2 boxes, only a fraction of the energy will make it through all the atmospheric obstructions. The proposed model assumes that solar radiation flows constantly with no interruptions through the other boxes and into the CO2 boxes which then absorbs this constant energy and passes it onto the surrounding boxes in the form of heat. This is not the case, the solar energy entering the atmosphere is not constant and the CO2 boxes can only absorb a narrow band of the incoming radiation which it cannot both store and emit through the other boxes which do not store or emit the same energy and when there is no incoming solar radiation to sustain the proposed action. If this were the case the nights would have become warmer and warmer until the night was as warm as the day and the planet would just another Venus and as dead.
In reality only a small proportion of the solar radiation band relevant to the CO2 boxes actually reaches them through the other boxes which obstruct the passage of this non constant radiation and not all of that is absorbed and here I think is the error. It is assumed that all the solar radiation from relevant absorption band makes it to the CO2 boxes through all the other boxes and does this constantly with no loss and if it did the model might be correct, as it is there are tens of thousands of other boxes between each CO2 box so the absorption and the storing and the re emitting of this narrow band cannot be total or anywhere near total and the incoming source is not constant nor does all all the solar radiation actually make it the CO2 boxes, it would only be a proportion the rest being intercepted and dissipated beforehand. The model also does not take into account dust and water in the form of clouds which both hold great quantities of CO2 and which takes it directly and quickly into the carbon life cycle at ground level and uses it up and none of this directly absorbed solar radiation is taken into account in the model. Its obvious that much of the remaining solar radiation absorbed by atmospheric CO2 is quickly and efficiently used up by the planets biomass cycle. I suppose that if you estimated the amount of urine produced each day by all the creatures of the earth and worked out how much CO2 makes its way through this biological process and how much of the proposed heat retention is taken out of the atmosphere by this process alone it would be no small amount!
While the model itself is viable it does not account for variables and other factors, it assumes a constancy of input and a far greater net absorption and conversion than is the case, nor does the model take into account the amount used and sequestered by earths prolific biomass. Imagine that every living thing that uses CO2 is taking energy directly from the solar radiation saturated atmospheric CO2 and using that energy within the CO2 molecule and this is something that the model does not take into account. We are not talking about a small amount either, the amount directly consumed and translated by the planets biomass is huge. The model might be of some greater use when all the other factors are included.
Ira thanks for the excellent analogy. While some suggest to put you in the dungeon under the steps Ira to censor you, I say the article is a good introduction to the first part of the issue.
I find when teaching with analogies it’s always best to add in the scientific language so people get familiar with it while learning the concepts; at the end would spruce it up. Something like the following might work, although we’d want verifiable empirical observational data and numbers to substantiate it:
“The greenhouse effect in essence is a simple, two step argument:
– CO2 (like a number of other gases) absorbs long wavelength IR. Any lab with a standard spectrometer can demonstrate this in under 30 minutes. What is to doubt?
– Such ‘greenhouse’ gases in the atmosphere therefore absorb long wavelength IR from the Earth’s surface. This heats them up, followed by all the consequent and well-known thermodynamic processes (radiation, etc.). Now, the magnitude of this effect for particular greenhouse gases, the strata of the atmosphere that are affected and the resulting effects on our immensely complicated atmospheric system – that is the debate.” – Richard Smith
Oh, it would actually be really great to see the afore mentioned 30 minute experiment in a video. I wonder if such a video exists or if one can be made by some enterprising skeptical scientist? What would it take to replicate such an experiment at home or at school?
Science “believed” or “accepted” is not much better than religion. Science replicated and verified (or refuted) is knowledge gained and infinitely better than “belief” of any form.
You’ve forgotten that before most of the excited CO2 molecules can re-emit the quantised IR energy, they’ve lost it in collisions to O2 and N2 molecules. The heating effect on the air is shown by the mirage effect.
That heat is convected to the tropopause where it can radiate to space at night!
See this: http://notrickszone.com/2011/02/11/is-co2-warming-a-mirage/#comment-15200
AJB says:
February 20, 2011 at 10:16 pm
“Until someone shows me otherwise, I maintain water rules the thermosphere – it’s a heat pump running at half throttle with a hunting governor (clouds) and a massive heat sink under it.”
+1
@pwl
“Oh, it would actually be really great to see the afore mentioned 30 minute experiment in a video. I wonder if such a video exists or if one can be made by some enterprising skeptical scientist? What would it take to replicate such an experiment at home or at school?”
Er… A spectrometer?
CO2 is not collected in simple layers.
The vertical distribution of CO2 in the air in a perfect mix would be equal from the ground upwards. This means you would measure 380ppm at sea level and in the mountains.
However, CO2 is heavier than O and has the tendency to collect more in the lower part of the atmosphere. This means that the concentration is higher on the ground than higher up in the atmosphere.
The main natural sinks are the oceans and plants and other organisms that use photosynthesis to remove carbon from the atmosphere by incorporating it into biomass.
Hi great diagram for a layman to have a stab at understanding the greenhouse effect.
Only one question. How much of that affect is contributed by manmade C02?
Reply to Joe 12.12 am.
CO2 is effectively perfectly mixed in the troposphere. H2O falls with height because of thermodynamic issues.
A bouncing ball absorbs and re-emits energy… so the analogy is pretty good… when the balls hit the earth they bounce off in different directions… but they do bounce off… all the greenhouse effect can do is slow down the speed at which the balls bounce off through the atmosphere of the earth… a bit like wind resistance… the balls do not endlessly bounce backwards and forwards between the earth and the atmosphere… the balls just bounce off the earth through the atmosphere at a slower speed… so basically the greenhouse effect is just balls…
@joe
“However, CO2 is heavier than O and has the tendency to collect more in the lower part of the atmosphere. This means that the concentration is higher on the ground than higher up in the atmosphere.”
Er… Winds? Downdrafts? Convective lifting? Stratospheric insertion (jet aircraft)? Jet streams?
Hi Ira,
I fully agree with your simplification to explain the GHGs effect, well done.
I just have a question about your reply at February 20, 2011 at 7:24 pm to what Ken Coffman says at February 20, 2011 at 5:15 pm.
You wrote:
“If not for the GHGs in the atmosphere (not just CO2 but also water vapor and other GHGs) it would be a heck of a lot cooler at night and, over the entire day and year, the Earth would be too cold to support life.”
How do you know that the atmosphere “it would be a heck of a lot cooler at night”? Do you believe that non GHGs couldn’t keep the Earth and the atmosphere warm via the thermodynamic exchanges at all?
I mean, if the atmosphere was made only of nitrogen I don’t believe that the ground temperature will be the same as the atmosphere wasn’t there at all.
The same “jumping pop-corn” analogy could be done for the non GHGs molecules which “bumping” on the ground “smooth” the ground thermal agitation during the day when the atmosphere is cooler, and “enhance” the same ground thermal agitation during the night time when the atmosphere is warmer. From my point of view this effect should exist and should be weighted against the sole radiative effect to establish how much the GHGs affect the Earth temperature. I also haven’t find any proof that an increase of GHGs in the atmosphere do not reduce the thermodynamic effect described above. It is my opinion that it could reduce the thermodynamic effect, and in that case it could be that the GHGs do not changes the Earth temperature at all, they could just change the place where the photons exits the system.
Massimo
Here is a problem I have with AGW. I think it is a true statement to say that if increasing CO2 since the industrial revolution has had an effect, then the recent record setting low in Bartlesville, OK would be impossible, since it is all radiative cooling. We shouldn’t be seeing record setting lows, and yet there it was.
I just realized something your physical analogy doesn’t take into account and someone else also refered to it, the earth being round. It’s more than being round though, it’s the amount of atmosphere at various points in the day that receive the Sun’s energy. Why is it that as soon as the sun is visable from the horizon at sun rise that the temperature doesn’t go to the maximum value as your analogy would imply? Because the amount of the air that the sunlight/energy has to travel through is GREATER, hence the energy is absorbed and radiated off into space at much greater amounts than directly overhead. Given that CO2 is NOT uniformly mixed in the air column but is greatest at sea level and given that greatest amount of energy transport to the ground is between 10 a.m. and 2 p.m. due to the sin of the angle because the earth is round, the only time that CO2 could possibly have an influence IF it even did would be only 4 hours per day. Your analogy as far as CO2 is concerned only works IF you discount the other 14 to 8 hours per day depending on the seasonal variation of day length. So not only is CO2 a non factor due to its being a trace gas, it has absolutely no effect due to its being a rarefied gas most of the day when the distance the sun’s energy has to travel is even greater through in the O2 and N2 volumetrically dominated atmosphere.
Being a trace gas, it is physically impossible for a CO2 molecule to collect and re-emit radiation from ALL or a substancial part of the N2, O2 dominated atmosphere at a ratio of 1 to .00034, to claim that kind of efficiency of heat transfer is simply magical.
Ken Coffman says: February 20, 2011 at 5:15 pm
On even numbered days, I believe this happens, but the effect is so small it cannot be measured. On odd days, I don’t believe this at all and think CO2 can only increase coupling to space (increase our cooling rate).
Ken, likewise I think CO2 has a significant cooling effect which is ignored … because it is an inconvenient truth that it does cool.
Everyone has heard about CO2 ‘s ability to absorb IR, but have heard about that its increased power of absorption is EXACTLY MATCHED with the increased power of emission. It’s a bit like saying a room gets cooler if you open the fridge … that’s the mind numbing stupidity of this “science”. Yes a fridge does make a room cooler (for a few minutes) and yes it does if you have a theoretical model that ignores one side of the equation.
Also, heat rises, hot air rises, the atmosphere is in constant circulation. The atmosphere is really part of the active cooling system of the planet, and increasing CO2 increases the rate of cooling because the sun-heated atmosphere is hotter than the bulk of space and the higher emissivity of the CO2 helps cool the atmosphere.
There is no question that heating and cooling of the earth are balanced (save the rounding errors), yet somehow people treat us as if the fridge door being open is cooling the planet!
We are constantly bombarded with nonsense diagrams with a minuscule sun heating the planet that is an object covering 6×10−5 steradians … where are the diagrams for the other 99.9995% of the sky which is at mind boggling -270C, or -455 Fahrenheit.
Come on guys! 99.9995% of the sky is super cooled, yet you are fixated by an “insignificant” (joke) little 0.0005%!!! (obviously the two are equal … but the point is the cooling effect deserves 50% of the coverage not the 0.0001% it seems to get (a
The theory of GHG’s assumes that heat loss is constant but it is not. It also assumes that heat adsorbed by the so called greenhouse gasses is re-radiated to the surface. It is not. The 2nd law of thermodynamics always applies so as temperature increases so heat loss increases. Also any energy adsorbed at height will only be re-radiated to the surface if it results in a temperature increase above that of the surface. This is questionable. Heat radiated is in all directions proportional to the temperature difference.
HaroldW says:
February 20, 2011 at 6:12 pm
Assuming the second layer also reflects half the balls downward (and lets the other half pass through into space), if you calculate the infinite sum, I think you’ll find the “2+” for the 2-layer model comes out to 3.
Ira Glickstein, PhD says:
February 20, 2011 at 7:53 pm
HaroldW, you may be right, but only if the downward balls from the upper Atmosphere layer in my physical analogy could fall directly on the Earth, without having to go through the lower Atmosphere layer. In my analogy, however, those balls have to go through the lower layer and only half of them will make it on the first shot. That is why I made the meter stop short of “3″.
I have to side with HaroldW. The reading on the scale will be 3, even considering the interaction with the second layer. The reading on the scale comes from the incident (yellow balls) rate plus what comes down from the tier 2 (middle): Reading = I + R2down. This is the same as R1up.
Now
R1up=I+R2down
R2down=R2up=R1up/2+R3down/2
R3down=R3up=R2up/2=I
Doing the algebra, one finds R2down=2I. Hence, the reading on the scale is 3. (This way of doing the math accomplishes the infinite series for you. In the first example when the third tier is absent, the equations are just R1up=I+R2down and R2down=R2up=R1up/2=I, which gives a reading of 2.)
Well, instead of Trenberth arrows there are violet balls now, but still no proof how much the back-radiated IR actually affects the surface temperature. Let’s measure the rate of nigh-time cooling above the desert with balloons measuring the humidity up to 10km or something and observe changes with changing humidity. Or lets feed the climate model with the desert data, extremely low humidity and CO2 – I bet we would obtain unrealistically low night time temperatures. All those models ignore simple fact – that oceans, soil and atmosphere have heat-retaining capacity and all models just scale the mythical 33K effect onto theoretically calculated back-radiation, so no wonder the climate models are wrong; they are based on nonsense.
@RichardSmith
Er… Winds? Downdrafts? Convective lifting? Stratospheric insertion (jet aircraft)? Jet streams?
You are right and that is the reason why it is going up. It would not go up without it.
The layer of CO2 is the whole atmosphere und not just a ring higher up, as it is shown in a lot of illustrations. CO2 is all around you.
Although your thought experiment does fulfill the conservation of energy, it violates the conservation of momentum principle. Specifically, the blue slab that absorbs purple balls does so without moving.
Of course this would break the analogy if the real effect subject to the analogy was significantly impacted by the momentum of the photons .
It doesn’t .
Few people have in mind what the real proportions in the atmosphere are .
15µ photons go very fast and transport a huge energy at their scale what has for consequence that there are very few of them .
In 1 m^3 of lower troposphere air you have approximately 10^22 CO2 molecules .
In this same 1 m^3 you have approximately 10^14 photons 15 µ – assuming radiated power of 300 W , everything in 15 µ what is not exact but we only need an order of magnitude .
In reality there are less 15 µ photons than that number .
So there are 1 billion times more CO2 molecules than 15 µ photons in 1 m^3 .
Therefore few CO2 molecules will meet a 15 µ photon and as the CO2 molecules have a huge momentum compared to the momentum of the 15 µ photon , the total momentum of the CO2 layer is constant for all practical purposes .
The collisions between CO2 and photons are just a negligibly small perturbation of the total momentum .
This also explains why the 15µ photons have little chance to go very far when 1 billion hungry CO2 molecules are waiting for each of them .
Actually the process that exites the energy levels of CO2 in a much larger manner than CO2 absorbtion are the collisions with N2 and O2 .
There are much much more such collisions than the available 15 µ photons .
As for the validity of the analogy , the biggest problem I see is that “doubling” CO2 doesn’t consist at all in “doubling” the atmosphere height .
The latter stays approximately constant , just the density increases .
So the right analogy should be that the initially single layer splits in 2 layers what increases the number of purple balls by 2 . Of course as there is no conservation law for the number of photons (purple balls) , this may be confusing for some .
But now this problem of non conservation of number of photons has always been a big problem for mechanical analogies where one uses concepts like balls whose numbers generally conserve .
To those who make 2nd Law objections to radiating from cool to hot: the “Law” is about a bulk effect, a statement about NET transfer.
Two guys having a hose water fight. One has a garden hose, one has a firehose. (We’ll restrict both to spray rather than jet, just to take kinetic effects out of the analogy. 😉 ) Both get wetted, but the wetting of the guy with the garden hose is much greater. That’s all the 2nd Law has to say about ‘direction’ of NET heat flow.
Ira’s analogy suffers far more from ignoring the thermal transfer of received energy from CO2 molecules, orders of magnitude greater than radiative loss. And then a very little of that thermal energy cycles back to CO2 molecules, which radiate another minute fraction before losing heat in collisions, etc. This logarithmic decline is far steeper than the ~.50 described in the model. Further, each radiative emission cools the CO2 molecule, which then chills the atmosphere around it by collision absorption of heat energy. (The specific heat and mass of the atmosphere is much lower than that of the surface, so air temps swing far faster than ground temps, it should be noted. But rarely is.)
It is interesting that figures I recall seeing for Mars (which has 30X as much CO2 in its atmosphere, despite the low density overall) suggest that it is actually 0.1°C cooler than its blackbody temp. In any case, it certainly isn’t warmed much by the GHG effect.
Note to Don Shaw: clouds are not a gas, GH or otherwise. They are water droplets suspended by Brownian motion and updrafts.
_Jim says:
February 20, 2011 at 5:45 pm
tallbrokes wordpress page
Hi Underscore Jim. You scored under on spelling there. :¬)
Doc Martyn wrote: “Why don’t we replace the vacuum in Dewer flasks with CO2?”
Dewar flasks are made of metal that emit very little IR keeping radiation losses down. In order to block IR in the few millimeters available between the walls in a dewar flask you’d need to have a fairly high pressure of some efficient greenhouse gas. This would reduce radiation losses, but on the other hand you’d get heat loss through conduction and convection in the gas, and the latter would be far larger.
tb;
tallbroke is what they call you in Japan and China. Hearing is believing!
;┘)
DocMartyn says:
February 20, 2011 at 5:13 pm
“human beings are very smart, they can take any piece of scientific knowledge and turn it into technology, so not has no one[?] used the CO2 green house effect for anything?”
The ability of CO2 to absorb energy in the microwave part of the electromagnetic spectrum and emit it because of the quantum energy levels of the vibrational modes of the dipole molecule are utilized to make the CO2 laser. Probably the most common high-power laser in use for industrial and medical purposes.
Not to mention a measuring device for determining the atmospheric level of CO2.
RichardSmith;
If it is so simple, why is it that so few understand it?
Your own explanation boggles the mind. A simple two step process followed by the consequent well known laws of thermodynamics. Show me the computer code from any two climate models out of the 20 or so in the IPCC report that are the same on that score. If it was that simple, they would be.
Well if you take off the glass ceiling roof of your “greenhouse” than I’m on board, but then you’d probably loose the whole classic “greenhouse effect” and probably adopt a rodent problem. :p
Maybe it should be called the greenhouse affect in connection with temperature?
Some seem to like the analogy some seem to hate it. I am in the middle. I like analogies but the problem with this one is that it is not realistic enough to come to any conclusions about the effect of small changes and it is clearly not simple enough to convince people who believe the effect can’t exsist. I also worry that it seems to focus on radiation dynamics and not enough on the simple issue of how energy is radiated to space. Like some others I think the real world is actually simpler than the analogy.
I see the real world as follows:
1) For the earth to maintain a constant temperature averaged over the whole surface averaged over a whole year the earth has to radiate all the energy it receives from the sun over that time. If it does not the balance of energy will have to be stored in or released from something. This does happen in practice with ice and the oceans being the main reservoirs. But for a simple analysis this can be ignored as can the fact that my opening statement is not exactly true given that one cannot measure heat balance using averages without taking thermal capacity into account.
2) The radiation absorbed by the earth is dependent on its albedo (reflectivity) and the output from the sun. These can be considered constant to the first approximation but obviously cloud albedo is a hot topic at the moment (Svenmark).
3) All the energy lost to space is by radiation. If one looks at the satellite measurements of radiation from the earth you see that at certain wavelengths the radiation is characteristic of the temperature of the earth’s surface. This is particularly true for the 9 -12 micron ‘atmospheric window’. However particularly between 5-8 micron where water absorbs strongly and 14-18 micron where CO2 absorbs the radiation is characteristic of a much cooler body. There is no point discussing this because here we have one of the few cases in climate science where we have actual measurements to prove something.
4) The reason why the radiation at these wavelengths is characteristic of a body at a cooler temperature is because that is exactly what is happening. Radiation at these wavelengths cannot be radiated directly into space from the surface because these photons are easily absorbed by water and CO2 molecules. All the detailed arguements about absorption and re-absorption are largely irrelevant. The fact is that the actual amount of energy lost into space at these wavelengths is dependent on the altitude this finally takes place. The basic theory is that the higher the cooler and the less the radiation loss. The greater the density of water and CO2 the greater the altitude at which unobstructed radiation to space can occur. So it follows that more CO2 ought to lead to less radiation and, to a first approximation, it does. The measurements prove it.
5) Thus the presence of water vapour and CO2 means that less energy is radiated into space from within their characteristic radiation bands so the temperature of the earth’s surface has to increase in order for energy radiated at other wavelengths to increase to compensate. This is the warming due to the, poorly named, greenhouse effect.
However the devil is in the detail and this is where analogies do not help. As the concentration of CO2 has increased in recent years it should have been a simple matter to provide radiation measurements supporting the theory. However, the measurements I have seen are not convincing. At the very least the variation of outgoing IR on a month to month basis is huge compared with the small linear decrease that the CO2 increase should generate. Clearly there are other transient factors which dominate the actual radiation balance so could any of these act as negative feedbacks? No one really knows.
One of the biggest issues I have is whether the effective height that CO2 radiates is already above 16km in the tropics and 8km at the poles. These are the altitudes at which the tropopause starts. That is the altitude where temperature no longer drops as one goes upwards. The satellite pictures I have seen suggest it is. If this is the case an increase in CO2 would not automatically lead to reduced radiation loss. Indeed it could actually lead to an increased loss if there were more radiating molecules at the same temperature. To me this is a crucial issue. If the tropopause is not increasing in altitude (and therefore cooling) I do not think a further CO2 based warming effect is physically possible. It should be measureable but, like the outgoing IR measurements, if such a change had indeed taken place I think we would have heard about it by now.
RichardSmith, you are a bit harsh. Different people understand stuff in different ways. As is clear from a lot of the comments here, many people don’t understand how greenhouse warming works, and attempts like Ira’s are good. You obviously understand stuff differently, which is lucky for you….
Of course, if people don’t want to understand, they will find a way not to.
I haven’t the time to read all of the comments, but I’d like to say that Indur’s attempt to visualize the “Greenhouse Effect” of the Earth’s atmosphere is not much better than Willis’, and Willis’ attempt was just plain wrong.
Sorry.
The natural phenomena you explain is real–earth would be a very different place without the GHGs–dominated by dihydrogen monoxide, I might add. I doubt any thinking, serious scientist would deny it. However, the question becomes whether the increase in carbon dioxide will ever reach a tipping point beyond which earth’s climate spirals out of control and is irreparably damaged. Since per-historic levels of CO2 have been many times the current level, I say such a supposition is completely unfounded, flawed, even dangerous–their hypothesis is false. I read all sorts of specious arguments by warmers that we’ve already passed this “tipping point”, and see precious little evidence supporting said arguments–even though they say the evidence is all around us. I think they’re idiots.
I also submit that having a warmer earth is beneficial–to plants, to humans, and to other animals. I’m not at all convinced that forcing humans into a no-carbon lifestyle (do you catch the contradition in terms there?) will be benefical in any way whatsoever. Evil people are using scare tactics and selective science to thwart civilization’s most fundamental freedoms and foisting upon them elitist controls–all in the name of some false notion that CO2 is king of the GHGs.
It simply isn’t.
It’s as if these pre-eminent scientists are completely lacking in the ability to do a thorough systematic analysis–and they call themselves “scientists”. I call them “what–iffers”, and “if” is actually the biggest, most irresponsible word in the English language. That makes them irresponsible scientists.
Good questions. In the daytime, the humid tropics have more clouds than the dry desert, and they tend to block and reflect back to Space some of the shortwave radiation in direct sunlight, which would limit the increase in daytime temperatures. At night, the clouds in the humid tropics absorb and re-emit longwave radiation back to the Earth which has the effect of increasing nightime temperatures. Relative lack of clouds in the dry desert exposes the surface to more daytime warming and more nightime cooling. I do not know the answer to your second question.
Joe says:
February 21, 2011 at 12:12 am
“CO2 is not collected in simple layers.
The vertical distribution of CO2 in the air in a perfect mix would be equal from the ground upwards. This means you would measure 380ppm at sea level and in the mountains.
However, CO2 is heavier than O and has the tendency to collect more in the lower part of the atmosphere. This means that the concentration is higher on the ground than higher up in the atmosphere.”
We DO measure 380ppm at sea level AND in the mountains.
Convective and turbulent mixing VASTLY outweigh the effect of gravity.
And the speed of air molecules at room temperature is about twice that of a bullit from a handgun, they collide and bounce off other molecules long before they can ‘fall’ to earth under gravity.
@davidmhoffer
‘A simple two step process followed by the consequent well known laws of thermodynamics’ is not what I wrote. The ‘consequent and well-known thermodynamic processes’ are part of step 2. The paragraph that followed the second step points out the problems that arise when we go beyond the first two steps, which is where all the problems arise. The two steps themselves are theoretically and empirically well-founded.
‘Your own explanation boggles the mind’. I was trying to avoid writing a 500 line post explaining in depth what it means when a molecule absorbs a photon so I tried to cut the corner by writing ‘well-known thermodynamic processes’.
Ira Glickstein PhD’s post is just so wrong on so many levels that it would take thousands of words to deconstruct it and we would be no better off. I’m not going to do this, nor am I going to write an alternative description of the ‘greenhouse effect’ in a comment that will disappear out of view about ten minutes after posting.
Dr. Robert Woods showed in 1909 that “Greenhouses” don’t work the way the “Greenhouse Effect” does! In point of fact, it is properly called the “Atmospheric Effect”, as there is that error in the comparison, as Greenhouses work because they are “convective boundaries”.
Alas, myths are so hard to destroy.
Max
@Ira Glickstein PhD
‘In the daytime, the humid tropics have more clouds than the dry desert, and they tend to block and reflect back to Space some of the shortwave radiation in direct sunlight, which would limit the increase in daytime temperatures.’
How do they ‘block and reflect’ this radiation? Do you mean ‘absorb’ – in which case, how do they ‘reflect’ it. Or do you mean that they absorb some percentage and reflect another percentage?
‘At night, the clouds in the humid tropics absorb and re-emit longwave radiation back to the Earth which has the effect of increasing nightime temperatures.
Hmm. So in Bangkok at night you can hold your hand up and feel all the warmth coming from the clouds?
AJB says February 20, 2011 at 10:16 pm
Arrgh, thermo should read tropo. Late and tired!
Pull the other Sydney says:
February 20, 2011 at 11:13 pm
Ira, Possibly another 2 stupid questions. Could you firstly, explain to me why the temperature difference is significantly greater between day and night in the dry windless desert than it is in the humid stormy tropics and secondly, has the desert day/night temperature difference changed over time in accordance with climate modelling .
These are good questions to Ira as he has reduced everything to radiation and is trying to measure heat content (the scales going down and reading more) at one place by using temperature. The only place where this is a correct metric is ocean temperature (the total ocean temperature) as that would give a reasonable guide to Earth heat content. Atmospheric temperature is not a measure of atmospheric heat content.
Ira has (like almost every physicist) completely disregarded atmospheric enthalpy – so let’s give him a pass and assume that he really meant to indicate that it was ocean average temperature that the scale was measuring and that is equivalent to heat content.
However, that creates a problem in another way – as the blue balls will bounce off the ocean with an infinitesimally small effect ‘on the scale’ as while the orange balls can go deep into the ocean and warm it up – the blue ones cannot. So from the ‘ocean scale’s’ point of view they are effectively of zero mass. Note that the oceans cover 2/3rds of the planet so this is not a minor consideration.
The disregard of water goes further. As the temperatures increase so water vapor levels will increase (Henry’s law) and this will lead to convection carrying the water vapor up and pulling drier air in over the surface which picks up even more water vapor and so on. Each molecule of water in the water vapor has taken the latent heat of evaporation with it from the surface. Of course as every AGW proponent will tell you this increases the green house effect as lots and lots more blue balls will be trapped and split by the water vapor (although as we said this will have zero impact on the oceans). However, as the water vapor rises the lapse rate means that the volume of air cools and eventually the water vapor condenses into water droplets and then into ice latent heat is given off to the surrounding air at each of these phase changes, with two effects. One the convection upwards continues as the air is warmer AND the (latent) heat in the water has been carried past the main CO2 trapping and two the droplets start reflecting incoming radiation. Or to use Ira’s little analogy as the scales get pushed past a certain point a sunshade is created over the scales and some if not all the orange balls are bounced straight back out to space without affecting the scales. This is the Earth albedo increase that like convection Ira has ‘forgotten’ to add to the analogy.
So to the simple analogy we need to add that:
* the blue balls have ZERO effect on 2/3rds of the Earth’s surface.
* Most energy reaches the tropopause (the top of the convective atmosphere) by convection NOT as blue ball radiation and this is well above the main density of CO2 so as these blue balls are created above the CO2 most escape without being caught
* Clouds that form as water condenses into droplets and then freezes into crystals raise albedo that can prevent most of the orange balls reaching the surface.
One of the aspects not considered at all in this simple (simplistic?) analogy is the overall impact of the hydrologic cycle on the heat into and out of the planet.
– Initially as water vapor the feedback to heating is strongly positive as water vapor ‘traps’ (catches far more blue balls) than CO2.
– As water vapor rises and begins to condense into clouds the albedo starts to rise and the feedback of the system to more heating starts to become neutral
– Eventually if the clouds are dense enough and reflective enough the feedback can go negative due to albedo bouncing away almost all the orange balls. (This has been shown with ERBE measurements)
There is not ‘one’ simple feedback for the atmosphere the effect of water vapor and convection and albedo from clouds leads to a stabilizing feedback.
(Of course this is as simplistic as orange and blue balls – but it at least shows some understanding of the hydrologic cycle and its effect on the energy flows rather than just looking at the overblown effects of CO2 )
Thanks Ira for your answers.
Can we infer from your explanation that the atmosphere over the tropics has a more enhanced “greenhouse effect” than does the atmosphere over a desert ( due mainly to water vapour) and therefore if the models are correct and c02 plays a role in enhancing the greenhouse effect we should see a narrowing of the day/night temperature differential in desert atmospheres over time.
@John Brookes
‘RichardSmith, you are a bit harsh … attempts like Ira’s are good.’
Ira Glickstein PhD’s analogy will bring no one closer to an understanding of the greenhouse effect. It is just so wrong. On the contrary, it will just get people confused.
Instead of presenting the greenhouse effect directly, Ira Glickstein PhD has us all wondering about a barrage of balls of infinitely elastic energy bouncing off a table top placed on a set of kitchen scales. The kitchen scales give us a temperature reading of the surface. The balls then split into two, which is supposed to represent absorption… I just can’t go on…
I’m trying not to be ad hom, but this guy has some issues.
I’m only relieved that Flubber somehow stayed out of the analogy.
. A greenhouse works primarily by preventing absorbed heat from leaving the structure through convection, i.e. sensible heat transport.
Ira, I have to take issue with this explanation. A greenhouse works because when light comes through the glass of the structure, it is shifted to longer wavelengths that can no longer penetrate the glass.
This is not true with the atmosphere and greenhouse gases because the probability function of reflection in a greenhouse is 100% while the probability function of reflection due to GHG gasses, at the concentration in the atmosphere today, along with the fact that the absorption wavelengths are small, is a small value (ignoring other factors).
I am not the Richard Smith who has posted so far on this thread.
The diagram is false because the purple balls bouncing up meet the purple balls coming back down. So the descending purple balls never reach the ground (the scales in the diagram) because the force of the ascending balls is greater than that of the descending balls. (They have twice the mass in the diagram.) The descending balls simply slow down the upward progress of the ascending balls. So energy is conserved.
As an engineer familiar w/insulating effects, the “greenhouse” effect, at least qualitatively, is pretty straightforward.
For any object at a higher temp than the surroundings, anything that impedes the loss of heat to the surroundings (in the earth’s case, cold outer space) will cause the object to either rise in temp or cool more slowly. Whether this is thru a layer of solid/liquid that confines convection/conduction and/or absorbs outgoing radiation, or a layer of gas that absorbs some or all outgoing radiation, doesn’t matter. It will cause some insulating effect. How much and where are the questions.
One caveat above is that I’m assuming the object’s heat input, either self-generated or from, say the sun, is NOT impeded by the presence of this “insulation”. GHGs typically don’t interfere w/short-wave incoming radiation from the sun. Something like dust, clouds or SO2 droplets in the atmosphere that absorbs, reflects, or scatters incoming solar SW radiation is a different matter — that can cause cooling. Willis E’s “Steel Greenhouse” was for an internally-heated body, not for an externally heated one w/an atmosphere transparent to incoming SW radiation.
Ira
You have produced a simple analogy which illustrates the principles behind the ‘robust science’ as proferred by those who expound the AGW theory.
However, this is far removed from the real world (with convection, conduction, evaporation etc which are the overwhelming features of our atmosphere and which dwarf the effects of CO2). Just one and perhaps the most obvious point you are missing is that none of your graphics illustrates the position when the sun is switched off (ie., night).
During the night, there are no yellow balls; there is nothing to weigh down the scales (which now drop to a recording of less than 1) other than the little purple balls which gradually during the course of the night completely dissipate so that no extra warmth is locked in.
During the course of the seasons, and on every clear night whenever there is a temperature inversion, any heat that has been built up is shed. One can see how little heat trapping effect CO2 has when one considers night temperatures on a cold, dry and clear night, or for that matter night time dessert temperatures.
Unlike a green house (with solid glass ceiling and walls), the so called greenhouse gases do not provide an inpenetrable blanket. They are full of holes and thus the heat/energy escapes.
If CO2 really had the ‘magic’ properties you suggest, double glazing would be widely spaced and filled with an enriched CO2 atmosphere which would then heat the glass and make the glass panes act as if they were panel heaters. Double glazing would not simply act as an insulator to slow down heat loss from the room but could instead be used as the main source for heating a room.
I am one of those people whose brains work by visulisation. Don’t forget the wheel was invented without the use of maths and the initial idea of the bouncing bomb was too so thanks Ira for the analogy.
As for the question by Doc Martyn why isn’t co2 being used in greenhouses, it is.
What I have been trying to find out is if these greenhouses need more heating than normal geenhouses?
Sorry that sould have read less heating!
As a quick sidetrack, Einstein was wrong to state there no difference between acceleration due to gravity as compared to acceleration through space. The reason being is I can simply place a gravity meter at my toes and at my head. If the meters read different then my acceleration is due to a gravitational field. The reason being is that in the case of a gravitational field the strength of gravity CHANGES based on your distance from the source.
If my acceleration is due to motion, then both gravity meters will read the same since my body will not experience a change in a gravitation field. In other words, the assumption Einstein makes is incorrect.
I should also point out that in the case of a real greenhouse there is not some substance in the air that traps the heat in that closed house. It is the glass that prevents movement of the air that causes heat to be trapped. In other words, the glass prevents convection of heat and this effect is NOT due to some substance in the air that traps energy. So the greenhouse effect in terms making your car or greenhouse warm inside on a cold day is due to a VERY different physical process then how the Earth’s atmosphere traps energy.
So to be really clear there is actually no greenhouse effect in the atmosphere in the sense as to how greenhouses work. So while co2 and other substances can trap energy in the atmosphere one must keep in mind that process is complete different then how a greenhouse works.
This explains why some point out there is no such thing as a greenhouse effect in the atmosphere (they are correct). However those same people accept that gases in the atmosphere can trap energy.
So the Earth’s and atmosphere trapping of energy is not due to stopping of convection or a simple preventing movement of air like a real greenhouse does. Thus the term greenhouse effect to describe co2 in the air is a very poor choice of words.
Richard Smith,
“Publishing this kind of rubbish just exposes you to ridicule.”
Why do you have to be so nasty? While it is true that analogies can sometimes confuse, Ira was attempting to deal with a specific problem, namely the misunderstanding over ‘where did the extra truckloads of energy come from?’ That’s it really, and I think Ira did a wonderful job. And based on the comments so far, so do many others.
A fascinating discussion and the core physics is not really in question. The ‘greenhouse’ hypothesis has been around for the best part of a century but until the 1980’s was dismissed out of hand by most scientists in the field. The problem is how the differential absorption of radiation by the CO2 molecule plays out in the real climate. Leaving aside the anthropogenic/not anthropogenic argument what we should clearly observe is a dependable relationship between changes in CO2 and changes in global mean temperature. The critical word here is ‘change’.
This is a very simply empirical proposition. Taking annual % change in T as our response variable and annual % change in CO2 emissions as our explanatory variable the R2 should tell us the proportion of variability in the former that can be explained by the latter. The data is easily available through the NOAA and setting up the regression in this way eliminates most of the problems in handling the relationship between the two variables, (eg data recalibration, UHI effects, unit root problems etc) but more crucially it targets the empirical hypothesis we are interested in.
Following Ockham’s Razor, I started with a simple linear regression. Result? R2 insignificantly different from zero. Slope, such as there is, negative. Fascinated I repeated the experiment using various data lags – zero R2. I then tried various fancy transforms of the explanatory data, I used ocean as well as air temperatures, then in desperation tried the combined air/ocean temperatures. Conscious that the effect may be more significant at higher concentrations I time sliced the data just to make sure. Result: R2 = 0. Finally I did something very bad: I regressed nominal CO2 against nominal temperature. Result: R2 = 0.77. Totally meaningless: autocorrelation is a seducer of souls. I haven’t tried it but I suspect there is a good relationship between global mean temperature and the annual goals scored by Watford FC.
At this point I assumed someone else had done this almost trivial statistical experiment before. In the International Journal of Geosciences (Soares, P.C., (2010) Warming Power of CO2 and H2O: Correlations with Temperature Changes, International Journal of Geosciences, 2010, 1, 102-112.) I found the corroboration I needed. Now I know the IJG is regarded as a rubbish journal by the cognoscenti but hey-ho if the author has done what I have done then we are both missing something or there is a rather large problem with the whole debate about the greenhouse effect.
Result of all of this: having unquestionably supported the greenhouse gas hypothesis I became a 50:50 sceptic. Maybe it’s right, maybe it’s wrong. A bit of data, a spreadsheet and an hour working the problem and I now need a lot of convincing that the beautiful bouncing balls have any real meaning.
Ps: Watford’s goal scoring did increase dramatically during the 80’s and 90’s but then flattened off – maybe even declined since about 1998.
Could someone explain why water vapour does not do to itself what CAGWA’s assert that increasing CO2 will do to it? The theory is that heating from increased CO2 will warm the earth, sea and atmosphere and so produce more water vapour, the foremost greenhouse gas in total effect, which in turn warms the system further and releases both more vapour and CO2 from the seas. So why doesn’t summer, with its increase in water evaporation levels, lead to an irreversible thermal runaway? (And don’t say because it’s winter in the other hemisphere?)
The problem is that when CO2 absorbs a 15 um photon emitted by the surface, before that CO2 molecule can re-emit it (half downward as people like to think), it is immediately absorbed by another atmospheric molecule through collision.
The excited CO2 molecule will experience many thousands of collisions with other molecules before it can re-emit that photon.
The up and down re-emittance is only relevant for atmopsheric heights of 10 kms to 20 kms high where the emittance time becomes faster since it is colder and the density of the atmosphere reduces the collision rate. Emittance to space from this height then becomes a 50:50 proposition.
Very few 15 um photons re-emitted by CO2 will make it back to the ground except from those that are 3 metres high, not from the tropopause. Think of how many CO2 molecules a 15 um photon has to skip past to make it back to the ground from 10 kms high.
If CO2 is absorbing 15 um photons on the way up, they are also absorbing them on the way down.
I found these references of interest :
http://acmg.seas.harvard.edu/publications/jacobbook/bookchap7.pdf
http://www.geo.utexas.edu/courses/387H/Lectures/chap2.pdf
As to the atmosphere not getting sunlight at night, consider the average temperature of
the atmosphere to be 255 K, an underestimate, figure how many joules it takes to warm the atmosphere to 255 K, and figure how much additional joules the earth
gets during a day. It works out that the joules we get during a day amount to about
3% of the amount of joules in a 255 K atmosphere- the atmosphere loses only about
3% of its heat overnight.
Ira,
Your explanation to Pull the other Sydney is incorrect. When the tropics are cloud free, they still don’t radiate near as much heat as a desert. Clouds play a role, but it is minor. Also, your explanation violates two laws of thermodynamics. Electromagnetic radiation will not transfer information from a cold source to a hot source. In other words, if the earth is radiating heat toward he CO2, then the CO2 cannot radiate heat back toward the earth. It must radiate it to deep space, or at least an object that is cooler.
I suspect part of the reason some don’t believe in the greenhouse effect is the fact that people cannot SEE greenhouse gases. We can SEE clouds- greenhouse gases operate the same way as clouds, but somewhat less effectively.
I know this analogy has been used before, but they operate the exact same way as a coat in winter. Your body is at 37 C, you put on your coat at go out in 0 C weather. The coat is heated up by your body, then radiates the heat away in all directions, half to the outside air, and half back to you, making you less cold than if you were standing naked in 0 C weather. Not believing that gases can have a greenhouse effect is like believing that wearing a coat in winter is a wast of effort, time, and money because it will keep you from freezing.
Master of Obvious says:
February 20, 2011 at 8:22 pm
Masters,
Satellites have been measuring Outbound Longwave Radiation (OLR) from the Top Of the Atmosphere (TOA) for over thirty years. That OLR is a fairly good measure of the rate of energy lost to space. Radiation from the earth’s surface (absent any atmosphere) is proportional to it’s Skin Surface Temperature (SST) to the fourth power. Any atmospheric processes that slow down the rate OLR can be considered a resistance. Think how clouds and high humidity reduce the rate of cooling at night. Now is CO2 appreciably reducing OLR? My answer is NO. For a more detailed explanation, click on my name.
If water vapor has an amplifying effect as climate modelers claim, why is the daily mean temperature in a dry, desert area warmer (in spite of nighttime cooling) than a humid tropical area at the same latitude? For example, in Yuma, AZ the daily mean temperature for July is 94.1 degrees, while Montgomery, AL is 81.8 degrees.
What the modelers ignore is the cooling effect of clouds due to albedo, precipitation , and evaporation.
One other comment on CO2. Since it only intercepts IR radiation in two narow bands, most of the IR passes unhindered to space. It’s like a greenhouse with most of the glass missing.
@cal, concerning the atmospheric window
Looks like we are arguing whether minor increase in 1m2 wall insulation will do any effect indoors, when windows and door are wide open into winter night
I still do no know answers on these basic questions
– when CO2/water vapor will absorb IR, it will pass it as thermal energy to surrounding molecules, or re-radiate it, or depends on the altitude
– if CO2/H2O re-radiates the IR, the frequency is the same as absorbed, or it is changed? Because matter radiates only based in its temperature.. or CO2 at -50C radiates 20C warm IR backwards?
– when all molecules including N2 and O2 radiate IR according to their temperature, how can we recognize and quantify the radiation effect of the single anthropogenic CO2 molecule, which makes only one of 10,000 other molecules?
Brian says
Note to Don Shaw: clouds are not a gas, GH or otherwise. They are water droplets suspended by Brownian motion and updrafts.
Thanks, you are absolutely correct water droplets are not a gas. Possibly you can help me with several questions.
Are you also saying that there is no local concentration of water vapor associated with those water droplets that are in equilibrium and respond like a greenhouse gas?
We know that clouds locally have a huge effect of preventing the suns energy from heating the earth’s surface during the day and also preventing heat from escaping in the evening. Are you suggesting that the impact of a cloudy day/night has nothing to do with the “greenhouse” effect? If not, much of the discussion about the significant effect of CO2 seems to be greatly exaggerated.
Also I note that:
Ira says
“Good questions. In the daytime, the humid tropics have more clouds than the dry desert, and they tend to block and reflect back to Space some of the shortwave radiation in direct sunlight, which would limit the increase in daytime temperatures. At night, the clouds in the humid tropics absorb and re-emit longwave radiation back to the Earth which has the effect of increasing nightime temperatures. Relative lack of clouds in the dry desert exposes the surface to more daytime warming and more nightime cooling.”
To Eric Anderson…
People are adding CO2 to greenhouses, but they do not notice any increases in temperature (not 1C or 3C or 4.5C or 8C).
See: http://academic.research.microsoft.com/Paper/5017614.aspx
I’m sure I’m perhaps too naive here, but I understand that all that happens is that photons hit electrons in CO2 or any other molecules in the atmosphere, or of course, on the surface of the earth — stone, earth, leaves, water….. and some of these re-emit photons again. Say, just for the argument, and assume a plane surface: 100 photons hit the earth, and 50 get re-emitted and hit electrons in atmospheric CO2 molecules (let’s assume there are no others).
Doubling the amolunt of those CO2 molecules in the atmosphere will not double the 50 photons travelling upwards which can only hit every other CO2 molecule and not twice as many. What’s up doc?
Thank you, Ira Glickstein. I will learn this post by heart and will keep a copy of your graphs for use with anyone I talk to about the misnamed “greenhouse effect”. Leave it to Anthony and WUWT to give us the science and then make the science understandable (with some mental effort) and explainable in “everyday” terms. I hope all the international experts reading WUWT volunteer to teach a day/period at their children’s or grandchildren’s or neighbor children’s schools and help teachers and students learn the real thing Invite the principal and the PTA pres as well. Hey, this might work at your local college, too!
davidmhoffer 7:18 pm 2/20: “Anyone with a reasonable understanding of your article ought to be able to walk up to a white board and explain it free hand to someone else in a matter of minutes. That’s the big piece we’re missing in the climate debate, widespread knowledge of the basics.”
I sympathize, KR! Of everything you own, your left hand is the most like your right hand, but it is a mirror-image coordinate system, and would not work right if you put it on the right hand. For readers who may not know about the “right-hand rule” it specifies a three-dimensional (X, Y, Z) coordinate system. You put your index finger on the X axis and then curl it towards the Y axis, and your thumb automatically points the direction of the Z axiz. If you use your left hand, you get a different result.
On one of my early system engineering jobs, we ran into conflicting coordinates because the British company that made our head-up display used a “left-hand” coordinate system, with Z pointing down, while the inertial navigation guys used a “right-hand” system with Z pointing up. Meanwhile, the targeting group used a “right-hand” system with Z pointing down. To make matters worse, the flight control guys oriented their X and Y axes according to the aircraft roll and pitch, while all the others used local horizontal for X and Y! There are a dozen variations of that theme and we happened on four of them. Our software did strange things until we introduced the appropriate coordinate conversions.
In those days, before every engineer had a computer on his or her desk and before computer-driven large screen displays, we used transparencies for presentations. Well, there are eight ways to lay a piece of plastic on an overhead projector, and only one of them is corrent. It is amazing we ever got anything to work, but we did!
You have also missed another aspect of the physical world. That the sun only warms a small portion of the planet at any one time frame. That means once the sun moves off one part of the planet, that part starts to cool down (throw more of those purple balls into space). Because of the Second Law that heat will attempt to move to regions of cold, mostly towards the poles.
If one wants to compare the atmosphere to a greenhouse, then that greenhouse needs to have most of its windows blacked.
Probably the most fascinating aspect of this article, as well as many of the others here at WUWT, is the range and diversity of comment and discussion they promote. I do not pretend to understand the technical discussion, but am still able to glean a piece of information here and there that paints a clearer picture of what is going on, at least for me. It is obvious that the complexity of the climate issue does not allow for any one explanation to emerge. What I have found that I like most about this site is that there is not the same sense of superiority and dismissive attitude here that I have found at so many others I have visited and, in some cases, continue to lurk upon. I can’t tell you who is right or who is wrong, (and apparently neither can anyone else) but I sure enjoy the debate.
[thank you . . now have you voted?]
There’s also a nice ‘pinball’ simulator located at:
http://www.cabrillo.edu/~jmccullough/Applets/PhET/greenhouse_en.jar
This might be worth playing with if you enjoy physical imagery. It allows you to look at both greenhouse gases and physical (glass) greenhouses. I suggest unchecking the “view all photons” box. Unfortunately, I can’t seem to get it to show concentrations on the “adjustable” scale…
You’re damn right I voted, and if I didn’t think it might poison the well I would also vote like they do in Chicago- often.
To: Alan McIntire
That is not how a coat works. Nor is it how the greenhouse effect works. Your body radiates heat to your coat and warms it. Your coat then radiates some of that heat to the outside. Your coat is now warmer than it was, but still not warmer than your body. So, your body now radiates less heat to your coat, so you lose less heat and your skin temp warms. Yes, you are now warmer with your coat on. Yes, the Earth is now warmer with an atmosphere. No, your coat will NOT radiate heat back to your body. It only radiates to objects cooler than itself. Again, this is a basic concept of Thermodynamics. So far, we have found no examples in the universe to refute this law.
Ira, please get this.
Other climatologists, please learn this.
RichardSmith;
Ira Glickstein PhD’s post is just so wrong on so many levels that it would take thousands of words to deconstruct it and we would be no better off. I’m not going to do this, nor am I going to write an alternative description of the ‘greenhouse effect’ in a comment that will disappear out of view about ten minutes after posting.>>>
You went from it is SO simple to it would take thousands of words…Hmmm. Logic gap?
Now you are clearly new to this site because if you’d been around for a while you would know that comments don’t disappear from view for presenting contrary views of science. Those kinds of comments are what the regulars live for. You appear to have policy at WUWT confused with RealClimate or other ChickenWarmingLittle sites where factual posts with contrary views are deleted out of hand.
So if you claim you can write something worth while, write it. Put up or…
Ira Glickstein, PhD says:
February 21, 2011 at 8:18 am
KR says:
February 20, 2011 at 8:10 pm
Ira I sympathize about “curl”. I remember when electromagnetic influences were introduced in physics with the ‘right-hand rule’; one of my classmates said quite loudly that “This doesn’t make sense!”. I looked at him, saw the thumb, index, and middle finger of his left hand extended, and gently corrected him…
I sympathize, KR! Of everything you own, your left hand is the most like your right hand, but it is a mirror-image coordinate system, and would not work right if you put it on the right hand…….
————————————————————————————–
Although it is 45 years since I encountered the right hand rule I do remember that there is a left hand rule as well. What perplexes me is that when I googled it the educational texts did not tie up with my memory in all details. My recollection is that if you grip a conductor with your right hand such that the (I)ndex finger is in the direction of the current the middle (F)indicates the direction of the field and the thu(M)b points in the direction of motion. Again from memory this is for a motor. The left hand rule applies for dynamos. So the left and right hand rules are not just frames of reference they are the physical embodiment of Maxwell’s equations. Please forgive me if I have remembered them incorrectly but I am sure the general principle is right.
Ira’s analogy study makes some sense but does not take into account a number of factors, especially regarding the carbon dioxide (CO2 )
namely the fact that net effect of CO2 is most probably not warming but zero warming or perhaps even very slight cooling (if you include the cooling caused by more photo synthesis due to higher presence of CO2)
which would actually make CO2 a make it a non-greenhouse gas (NGHG)?
Also, oxygen is a weak greenhouse gas as it also has a very weak absorption in the 14-15 um range.
theories and explanations are all nice but without actual test results they all mean very little/
we need to have actual test results showing the net warming and cooling properties of each of the O2, CO2 and H2O,
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Ira Glickstein, PhD – February 21, 2011 at 4:43 am
At night, the clouds in the humid tropics absorb and re-emit longwave radiation back to the Earth which has the effect of increasing nightime temperatures.
Its this re-emit back to earth thing again… the clouds would only re-emit back to earth when the earth is colder than the clouds… usually the clouds are cooler that the earth…. but the clouds are warmer than the vast empty space above them… so clouds slow down the rate at which the earth cools… clear skies – rapid cooling into space… cloudy skies – slower cooling into the clouds.
The clouds only re-emit back to earth at night in your dreams.
I would like to put a simple question. The whole atmosphere between the surface and the near vacuum of space is filled with CO2. So how come the OLW radiation in the CO2 absorption bands from the surface manages to get unhindered to some altitude, then gets absorbed, re-radiates half down towards the surface, again unhindered and half towards space, again unhindered? It doesn’t make any sense to me.
The way I see it is that, in the wavelengths that CO2 absorbs, the energy is struggling to get to the TOA where it finally manages to radiate a few hundred milliwatts per square meter to space. Negligible in fact. It is that narrowing of the infra-red spectrum that caused the greenhouse warming because the surface has to become warmer to radiate enough energy to space through a narrower window.
Further calculations show that 90% of the energy in the CO2 absorption band is absorbed in the first 4.5 meter and 99% in the first 9 meter. I base my calculations on “A Theoretical Analysis of the Effect of Greenhouse Gases in the Atmosphere” (http://www.lavoisier.com.au/articles/greenhouse-science/climate-change/Hammer2007.pdf) from Michael Hammer. It is well worth a read and he also has more articles on Jennifer Marohasy’s website.
RichardSmith;
Hmm. So in Bangkok at night you can hold your hand up and feel all the warmth coming from the clouds?>>>
In that single, sarcastic question, you just announced to every single reader with a basic knowledge of radiative physics that you do not have a single clue what you are talking about. You shoot your mouth off about how wrong other people are, won’t provide an explanation of your own on flimsy excuses, and then ask a question like that.
Your hand radiates heat and so does everything else including the clouds. If your hand is radiating more heat than it is getting back from the surroundings, it feels cold. If you remove the heat from the clouds, it feels even colder than it did before. And in the unlikely event that the cloud is radiating enought heat to exceed what your hand radiates, then yes, you would feel the warmth from the cloud.
Either you haven’t a clue what your are talking about or you are deliberately obfuscating the discussion.
Fred Souder says:
February 21, 2011 at 10:53 am
To: Alan McIntire
That is not how a coat works. Nor is it how the greenhouse effect works. Your body radiates heat to your coat and warms it. Your coat then radiates some of that heat to the outside. Your coat is now warmer than it was, but still not warmer than your body. So, your body now radiates less heat to your coat, so you lose less heat and your skin temp warms. Yes, you are now warmer with your coat on. Yes, the Earth is now warmer with an atmosphere. No, your coat will NOT radiate heat back to your body. It only radiates to objects cooler than itself. Again, this is a basic concept of Thermodynamics. So far, we have found no examples in the universe to refute this law.
Ira, please get this.
Other climatologists, please learn this.
I see this repeated again and again and shows no understanding of radiative heat transfer. Your body does not radiate less to your coat and become warm. Your body radiates even more as its temperature increases but your coat also is warming and radiates back to the body. There is no barrier between the body and radiation from your coat. It is the NET change in radiation that determines equilibrium temperatures and the net change is always in the direction of hot to cold. The laws of thermo are satisfied even though a cold body radiates to a warm body.
It is a cute graph, but significantly lacking. The CO2 absorbs the energy, bounces into other particles in the air transferring some of that energy, the air mass warms, rises, and shoots the energy out to space. You have barriers and ignore convection, the largest part of the entire picture when it comes to getting the heat out into space.
You also neglect the fact that air in the lower part of the atmosphere will automatically be warmer than at the top, hence, why the temperature for the surface is higher than that calculated for a black body.
I do think that the “greenhouse” gases do help warm the atmosphere, a little, but the warming is accomplished and ends after a very low threshold of the gasses, and once the amount reaches saturation for the wavelength band, nothing more will come of it.
Because we have water, ice and steam, we pretty much are guaranteed saturation of the wavelengths with water alone.
To take your ball diagram to the proper level, do the following. At 10 feet then 5 feet, then 2.5 feet and so on until you reach top of atmosphere place one of your ball creators, because that is the saturation distance for CO2 to absorb 100% of available energy. Each of the balls going down will be captured by the level just below it and just above it, split and go out again.
Now, take that same calculation and start with 5 feet. Tell me what the difference is. A doubling of CO2 will cut the saturation distance in half. I have a feeling the difference between the two calculations will be negligible, and fully offset by negative feed backs.
Neil Jones says:
Great explanation for the day-time, but what happens when the sun goes down?
Yes, the explanation given in the article is fine as far as it goes for the daytime case, but it only gives a small part of the necessary pictorial science for the layman. If we wish to discuss the somewhat erroneously titled ‘greenhouse gas effect’, it is best to start with a diagram of the the nighttime analysis of IR-active gases (alias greenhouse gases) in the atmosphere.
This first diagram would show the way in which the idealised atmosphere cools into space at night through the net emission of IR energy from its IR-active gases. Adding more IR-active gas, e.g. CO2, increases the net cooling.
The second diagram would be as shown in the article. Adding more IR-active gas increases the net heating.
The other diagrams which must be included for a more complete analysis are:
– cloudy nights and days over dry land (higher temperatures at night, reduced by day)
– cloudy nights and days over moist land or water (moderated temperatures)
– night and day over high reflective surfaces (cooler at night, warmer by day)
Thus IR-active gases are not just ‘greenhouse gases’, and because of their cooling properties they could equally be called ‘refrigerator-greenhouse’ gases. Neither term is actually correct, but it would alert the interested party to the fact that the single sunny day model view of IR-active gas concentrations nowhere near explains the full reality.
richard verney says, February 21, 2011 at 6:38 am
Well no, it’s all a matter of degree. If you widely space the glass convection currents become established which overpower the minor radiative advantage. That’s why modern window designs use a low emissivity coating on the cavity face of the inner pane only (e.g. K glass). The cavity is about conduction, expensive double glazing is Argon filled too. But there’s the point …
You cannot divorce the radiative from other thermodynamic phenomena of what you’re dealing with, especially where you have a condensing agent like water that has a huge thermal capacity in liquid form and moves big globs of latent heat at every state change.
“Climate scientists” seem to suffer from a peculiar form of myopia – radiative blindness. You only have to glance at Trenberth’s famous cartoon to see that. The phase transitions going on inside clouds are total guesswork and in my opinion are being grossly underestimated. Keep a kettle boiling on the floor and watch how much and the manner in which heat gets to the ceiling, why do you think tropical clouds are anvil shaped? They’re big radiators, getting rid of the latent heat.
Fred Souder says February 21, 2011 at 10:53 am
Fred, please learn about conduction, vapour barriers and Gortex.
Climatologists (and others suffering from radiative blindness), please get this.
I’ve never read such nonsense, next you’ll be measuring the comparative TOG rating of a black and white coat with a spectrometer.
http://www.scribd.com/doc/34962513/Elsasser1942
Dr. Glickstein, the above is for a paper on radiative heat transfer by infrared in the atmosphere. I hope this will assist you.
There are people that don’t believe in the greenhouse effect at all!?
Wow.
Speaking of Wow…
@Joe Lalonde:
February 20, 2011 at 6:17 pm
Double wow.
What Bigdinny said, and yes I HAVE voted!
Special thanks to wayne and cal for input that really made me think about all this despite my lack of physics.
Also, as others point out, Tallbroke in Japan is a nice thought. Though, if as Einstein has pointed out, everything is rerative, he’d probabry be Verytallbroke…
Albert Kallal says:
February 21, 2011 at 6:54 am
“If my acceleration is due to motion, then both gravity meters will read the same since my body will not experience a change in a gravitation field. In other words, the assumption Einstein makes is incorrect.”
This is a misunderstanding of the equivalence principle, since you have introduced a situation that is explicitly excluded. Formulation of the Principle of Equivalence is that at any local (that is, sufficiently small) region in spacetime it is possible to formulate the equations governing physical laws such that the effect of gravitation can be neglected. The important condition is that the region in spacetime is sufficiently small but you have made it arbitrarily large.
In any case, it was intended to be used as a tool to aid insight into gravity, not as a law in its own right. It was while using the thought experiment on a light beam in an accelerating frame that Einstein deduced that gravity would bend the path of light. He also worked out that a clock in the nose of an accelerating rocket would run more slowly than one on the floor, and used the equivalence principle to draw the conclusion that a clock in a gravitational field would run more slowly than one further away. It was a brilliant insight and comments like ‘Einstein was wrong,’ does him a disservice.
Gary Wilson was correct in his reply to Fred Souder. The fact that NET radiation is from warmer to cooler does not mean ALL radiation is from warmer to cooler. The atoms in your body are not psychic- they don’t know what direction the joules came from, or will come from. Each atom in the warmer body radiates in a random direction. Each atom in the cooler body radiates in a random direction. The NET effect is that the warmer body will radiate away more than it receives from the cooler body, the cooler body will receive more than it radiates away towards the warmer body.
Here’s a numerical example:
Let the flux from the sun to the ground be 4 joules/unit time*unit
area,
and stay constant.
–> SUN
–>
–>
–>
With no greenhouse gases, the earth will either heat up or cool down
until
the outgoing flux from the earth is equal to the incoming flux from
the sun.
Sun –> O O O O <– <– <–O O–> <–
You've now got an unbalanced situation where 5 joules/unit time*unit
area
are hitting the earth, 4 from the sun and half of the 2 from the
atmosphere,
and only 3 joules per second are leaving the earth, the 2 not
absorbed by
the gas, and half of the 2 from the atmosphere. The atmosphere will
gradually
warm up until outgoing flux from the atmosphere, plus the fraction of
the flux from the
earth not intercepted by the atmosphere, equals the incoming amount
from the sun.
Since in my example, half of the outgoing flux is intercepted by the
atmosphere,
the watts hitting the earth's surface will increase to
1/(1-1/4) = 4/3 of 4 joules/(unit time*unit area) = 5 1/3 joules/(unit
time*unit area).
Remember the atmosphere is intercepting half of this, so 16/6 joules
(unit time*unit area)
is intercepted by the greenhouse gas atmosphere, and another half,
16/6 joules, escapes
directly to space.
The final equilibrium balance is
atmosphere 16/12 Earth
O–>16/12 to earth 16/12(from atmosphere)–>Earth
Sun –>4 to earth
16/6 to atmosphere <–
Earth
16/6 to space <–
In the above example, 4 units are incoming from the sun to the earth,
4
units are outgoing from earth to space, and the earth's surface is
at 5 1/3 joules, a multiple of 4/3 the radiation received by the sun
and returned to space.
Note the NET flow is positive at earth's surface +16/3 to atmosphere, -8/3 from atmosphere.
Comparing WUWT readers to Einstein because of something they typically fail to understand, is ridiculous.
davidmhoffer says: February 21, 2011 at 10:57 am
You keep misquoting me. A lot of anger bubbling in there, davidmhoffer. Anger that is stopping you reading what I wrote:
‘You went from it is SO simple to it would take thousands of words’. No I didn’t. I said it would take thousands of words to deconstruct Ira Glickstein PhD’s analogy. The analogy is so wrong (as a number of other commentators have pointed out) that there is really no point in wasting more time on its details.
I have already told you I that I used some shorthand to save some space.
‘…comments don’t disappear from view for presenting contrary views of science’. I wrote ‘disappear out of view’ – there is a difference. At the time I write this there are 171 comments. Do you think anyone would thank me for writing in the middle of all that a description of the greenhouse effect so long that even you could understand it? No, Ira Glickstein PhD put his baloney up in the first place, it’s not my job to rewrite it.
I didn’t realize that I was presenting ‘contrary views of science’. The two points in my previous post 1) CO2 is a GHG and 2) GHG’s absorb longwave IR are incontestable, unless, that is, you believe the moon is made of green cheese and grassy knolls.
I happen to be strongly skeptical when it comes AGW. Which is why it annoys me that the guys at RealClimate will be laughing their heads off when WUWT posts something as flat wrong as Ira Glickstein PhD’s rubber ball and kitchen scale analogy. It doesn’t work on any level.
Dennis Wingo says (February 21, 2011 at 6:00 am): “Ira, I have to take issue with this explanation. A greenhouse works because when light comes through the glass of the structure, it is shifted to longer wavelengths that can no longer penetrate the glass.”
(1) Try opening a window in the greenhouse; does the greenhouse temperature drop because infrared light escapes through the opening, or because colder outside air is entering and warmer inside air is escaping?
(2) Build a seond, identical greenhouse using material transparent to infrared light. Is the second greenhouse warmer, colder, or pretty much the same temperature as the first?
davidmhoffer says: February 21, 2011 at 11:27 am
RichardSmith: ‘Hmm. So in Bangkok at night you can hold your hand up and feel all the warmth coming from the clouds?’
davidmhoffer: ‘In that single, sarcastic question, you just announced to every single reader with a basic knowledge of radiative physics that you do not have a single clue what you are talking about. You shoot your mouth off about how wrong other people are, won’t provide an explanation of your own on flimsy excuses, and then ask a question like that.’
Blograge! I knew you’d like that question…
HenryP says:
February 21, 2011 at 11:21 am
Also, oxygen is a weak greenhouse gas as it also has a very weak absorption in the 14-15 um range.
It doesn’t, see here:
http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2N2O2.png
Sigh. Discussions with real life (meatspace) warmists never reach this depth. They don’t even know that the CO2 GHG effect is expected to be logarithmic (No, not one of the people i know).
Yet they expect me and everybody else to pay for their economically harmful green energy schemes (and they don’t understand that economically wasteful endevours are also wasting resources). Must find ways to exploit them more…
The imposition of a second layer of GHG is not what would occur in real life. A doubling of the GHG layer would merely make the initial layer shown in fig.2 be twice as thick, which would not change the “splitting” of the energy at all, meaning that fig.2 is the only working model.
Additionally, the imposition of the second layer is above the first layer. Why this arbitary location? If the second layer is located below the first layer, then the overall amount of “ball energy” hitting the earth is reduced.
Adding the second layer complicates the entire scenario and depending where it is arbitarily placed then the result is either less or more energy hitting the earth. This should show that the logic of a second layer is incorrect.
Consequently I believe that the third figure is not correct and the overall analogy should have stopped at Figure 2. This would imply that the amount of GHG is irrelevant as there is an upper limit on the impact on temperature, which is what I understand actually theoretically occurs.
(Long time reader, but first time poster)
Thanks, Ira. I figured something like that, but in all honesty, I’m getting more confused by the moment. The arguments against GHG having any effect seem pretty good, as do the arguments that it has an effect. To quote “Vinnie” Barbarino, “I’m so confuuused.”
However, when it comes to science, that’s a good thing. It puts the brakes on orthodoxy.
Now I’m off to build two greenhouses and fill one with CO2.
I never understood, how and why most of the models and explanations of the “greenhouse effect” don’t even touch upon the most fundamental fact — namely, that a very substantial portion of CO2 present in the atmosphere at any given time is absorbed by the plants, and chemically transformed into sugars, other carbon compounds, and oxygen, therefore removing the alleged “greenhouse gas” from the circulation (even if the “greenhouse” analogy could be used to explain, what is going on in the atmosphere physically, which is unlikely — for the simple reason, with very complex consequences, that the Earth’s atmosphere is NOT a greenhouse by any measure or analogy).
Moreover, the higher the concentration of CO2 in the atmosphere, the faster plants grow, and the larger is the volume of CO2 being absorbed and transformed.
Moreover, any discussion of the published CO2 data is meaningless without mentioning that these figures are obtained downwind from the active volcano, in the vicinity of the volcano.
Moreover, it has been mathematically and physically proved, several times, by many respected scientists, that CO2 ceases to act as the reflector of heat (infrared radiation) at concentrations above approximately 300 ppm.
The whole “greenhouse” analogy doesn’t hold water.
Alan and Gary,
I should have said “radiative heat transfer” rather than radiation.
You are wrong here: The atoms do know what direction the radiation comes from. It has momentum.
You are correct here: When electrons (or other qm potential energy) spontaneously drop in their energy levels, the EMR follows a random direction. This EMR is unbounded by time, and is a form of communication with the object receiving it. If it is directed from your body back to your coat, then the electron in your coat will absorb it, knowing the direction and the source. Momentum is conserved. This only will work if the electromagnetic radiation has a source and a receiver. The reverse process also occurs. In this you are correct.
That is not what I am having a quibble about. People keep claiming that heat is transferred from the CO2 back to the ground. No, it is not. It can’t if the ground is warmer that the CO2.
As for your coat analogy, the heat being transmitted from your body to the surroundings with not coat is proportional to the temperature difference of your body to the surroundings to the 4th power.
If you put on a coat, your body is now radiating heat to your coat, which is warmer than the surroundings. (you are also primarily conducting heat, way more than you are radiating, and the coat is an insulator, but this is not what Gary was talking about). The heat transfer from your body to your coat by radiation is always in that direction (as is the conduction). This heat transfer is slower than it would be to the surroundings because of the smaller temperature difference. This is why you are warmer. You are losing less heat. It is not because the coat is actively warming you.
Also, our statements are mathematically equivalent. Again, radiative heat transfer ONLY occurs in the direction from a hot source to a cold source.
How do we know where the molecules are going? Do they give us advance notice?
Better to be silent and thought stupid, then to speak and remove all doubt.
M. Twain
@izen
I know that it is measured at different places but the data is not the same.
Example(same time different location):
Park Falls, Wisconsin, United State: ~390ppm
Ascension Island, United Kingdom: ~ 383ppm
Baltic Sea, Poland: ~ 405ppm
The Aircraft Profiles also shows also that it varies in the first 8KM more or less depending on the season. http://www.esrl.noaa.gov
Above 10km molecules and atoms tend to separate, with the heavier gases beneath the lighter ones, in a layer called the heterosphere.
Sadly all these thought experiments fail on the issue of there being no photons until there is an interaction. That interaction could be with other wavefronts coming up from the surface or with other CO2 particles… It should also be noted that most of the IR is from water vapor and not CO2 except in a very few very dry areas of the earth. In those dry areas the atmospheric window is much larger. Like Venus, CO2 on earth only provides a couple of narrow slats to cover the full emission window.
This type of thought experiment only tends to cement a FALSE idea of what is actually happening with the result of an increased magnitude of warming more easily accepted.
AJB
Sorry for the slow reply. Eventually, the only way to lose energy to outer space is radiation.
What you say is true. I, like Dr. Glickstein, was trying to give a simple answer to a question.
The question I was answering was this: “…. Cold rarefied gases measurably increase the earth’s surface temperature? No, sorry, I don’t buy it. ” I think my answer deals correctly with that question.
What you say about heat transport by evaporation, condensation and convection is true. As far as I can tell, the vast majority of heat is removed from the equatorial ocean and lower atmosphere by evaporation, transport and convection. However, the only way the earth can lose heat to outer space is by radiation.
No, a simplistic application of radiative physics does not apply. But, yes, eventually radiation rules. The mechanism just isn’t really simple. 😉
Well I would have one immediate criticism of your gold and purple ball diagram; although I like some aspects of it.
WHY !! ?? do ALL of the gold balls go right on by the atmosphere as if it wasn’t there. For a start, we know that a goodly fraction of the gold balls, which are actually a bluish shade of gold, are Raleigh scattered by the atmosphere, and split into two streams just like your blueberries. No they aren’t absorbed by the atmosphere, so don’t really change the atmospheric Temperature; but still the atmosphere splits them into two equal streams; up and down.
Then there are also some red and black balls in the gold mix, that DO get absorbed by the atmosphere, just like your blueberries, and they too contribute to the atmospheric Temperature; and from there they are quite indistinguishable from the blueberries; even though the atmospheric absorption mechanism is different (in detail) from your surface originated stream.
I also think the concept of a second layer of GHG due to “a doubling” is not a good analog. I prefer an infinity of very thin layers; each of which captures a certain amount of energy from either gold or red/black balls.
I think it is a mistake to think of some layer thickness that basically “saturates” its CO2 band. So a micron thick layer is possibly saturated; and what it captures warms that layer which them emits a thermal spectrum (of blueberries up and down).
The sparseness of that layer, is accounted for in the spectral or total emissivity of the layer. So a thin layer at 288 K is emitting 390 W/m^2 times epsilon, both up and down. It then becomes clear that gases are no different from liquids or solids in their emission of a thermal radiation continuum, that is a function only of the Temperature. The solids and liquids, just get to near a 1.0 emissivity, in a much thinner layer.
A gold metal layer beaten out to a 100 Angstrom thick film, is also not going to radiate like a solid; it is going to start looking decidedly more gas like, because of its extremely low thermal mass, so that a small radiation can result in a large Temperature drop (unless replenished from some continuous energy source).
Which brings me to another issue.
A lot of people toss out “Kirchoff’s Law” as requiring that something that absorbs such and such spectrum energy must also emit the same. So they claim that nitorgen and oxygen don’t absorb IR, so they don’t emit IR either. This forces them to invent a two step process, whereby CO2 (or other GHG) absorbs some LWIR radiation, and then thermalizes it by collision with the other molecules, and then sometime later, a warmed over N2 molecule clobbers the CO2 again, and re-energises it so it can now emit the specific CO2 spectral band of radiation that it started with. And that is how they see the atmosphere radiating LWIR. It can therefore only be emitting the CO2 specific LWIR band; say 13.5 to 16.5 microns. Why not the 4 micron band also?
So this is a consequence of Kirchoff’s law.
Well the problem is that Kirchoff’s Law applies ONLY in a state of equilibrium. It doesn NOT apply to a steady state condition; and the earth atmopshere absolutely never ever has been in any state of equilibrium. It is constantly exchanging energy with its surroundings; there’s a contunuous (in daylight) input of solar energy, and a continuous 24 hours input of LWIR thermal continuum radiation.
Kirchoff’s law does not apply to this condition; so the general inability of N2 or O2 and Ar to absorb much in the way of LWIR radiation, in no way prohibits the same gases from emitting a thermal spectrum just based on the Temperature.
Notice that so far as I am aware; there are precisely three Physical Constants that are defined as having absolutely accurate known values; with no error bars.
Those are (c) and (epsilon naught) and (mu naught), the permittivity, and permeability of free space; which together yield (c) as 1/sqrt(mu-naught times epsilon naught). That result is a direct consequence of Maxwell’s equations for the electromagnetic field.
So Maxwell did not get banished to oblivion by the quantum theory. The Bohr atom which arbitrarily declared that just for the hell of it, an electron in a “preferred” orbit of the Bohr model, would not be allowed to radiate, unless it jumped from that orbit to another. A completely unjustified piece of nonsense. Well I suppose a lawyer type might say that that refers to something that is “not in evidence”.
Well we shouoldn’t be too hard on Nils Bohr, it was an ingenious step around a thorny roadblock, but one that immediately led to a whole lot of “aha” understanding of atomic structure.
Well the de Broglie and Schrodinger Wave mechanics got back to common sense by establishing a different concept for the electron orbitals, as simply being places with a certain map of probablility of finding the electron somewhere there. Well you see that now the electron does not have to go whizzing around in some Bohr Sommerfeld eliptical planet like orbit on Bohr’s say so that it wouldn’t radiate. Radiate ! I’m not even moving; why should I radiate. How easy is that ? Maxwell is resuscitated, and we can forget that Bohr’s overstepping reality got us back to sanity eventually. Well no we shouldn’t forget it; it was the work of pure genius to see us all comfortably through an amazing time in physics. I wasn’t there to witness it all ;but I do admit to having been in on the discovery of the neutron , by Chadwick. Well I was a bit busy doing other things to attend those lectures; but I was around at the time.
Well the upshot of all of this, is that Maxwell’s explanation of EM radiation from accelerated electric charges, as the origin of thermal radiation from anything that is above absolute zero, including gases, is quite sound. I’m sure there is a quantum explanation as well; but everytime a molecular collision occurs in the atmosphere; both molecules undergo accelerations along with the electric charges thay contain; so there is plenty of bumping going on to emit thermal radaition.
But it is NOT an aequilibrium process, so don’t expect Kirchoff’s law to apply.
Ira
Ira Glickstein at February 20, 20111 at 7:24 when commenting upon a post by Ken Coffman February 20, 2011 at 5:15 pm, says:-
Sorry Ken, but, although the nighttime Earth is cooler than it is in daytime, it remains warm enough to continue emitting longwave radiation. If not for the GHGs in the atmosphere (not just CO2 but also water vapor and other GHGs) it would be a heck of a lot cooler at night and, over the entire day and year, the Earth would be too cold to support life. Those are the facts. Please do not allow the distortions of the facts about CO2 sensitivity and the temperature record by the official climate Team lead to an equal and opposite reaction in the wrong direction.
///////////////////////////////////////////////////////////////////
Whilst your post deals with the role played by greenhouse gases in general, and one example depicts the effect of a doubling of ALL greenhouse gases, Ken’s comments are directed at looking at the role played by CO2. As we all know, the debate underpinning AGW is what role does CO2 have and what is the effect of doubling this particular gas?
I have yet to meet a sceptic who challenges the assertion that a CO2 molecule has the ability to absorb LWR and to re-radiate that absorbed energy. However, the issue is not how a CO2 molecule in isolation may behave but rather how it behaves in practice in the real world environment to which it is a part. The manner in which CO2 behaves in the real life environment of the Earth’s atmosphere (including the manner in which the Earth receives its energy from the sun during days, during seasons) may mean that sensitivity is zero, or close to zero, or at any rate insignificantly small. The problem is that presently, there has been no real life experiment measuring this.
There are many reasons to suspect that CO2 in the real world has little greenhouse effect, for example, it may be that CO2’s power of absorption is largely cancelled out by its power of emission, it may be that due to the time required to radiate energy the majority of CO2 molecules have already by way of collsion/thermalisation lost the LWR energy that they had previously absorbed (when radiated from the Earth’s surface), the fact that Mars notwithstanding a rich CO2 atmosphere (admittedly of little density) does not appear to possess an enhansed temperature above its theoretical blackbody temperature (in fact some calculations suggest that its observed temperature is ever so slightly less than its theoretical blackbody temperature), etc. Further, air has little heat capacity and the wavelength of re-radiated radiation from CO2 is such that it cannot effectively penetrate the oceans (depth of penetration about 10 microns) and at most it simply boils off a small layer of the ocean which probably has a net cooling effect.
Sometimes, nature allows us to view a real life experiment. Occassionally, we get a glimpse at the real life effect of CO2 and how it operates when water vapour is removed from the equation. E.M. Smith posted an example (Frostbite Falls – 23rd January 2011) in which he looks at a record low set at International Falls on Friday 21st January 2011. That night was a low humidity, clear, still night. The clear skies meant that there were no clouds to blanket IR radiation. The fact that it was still meant that there was little turbulence or convection processes ongoing. The fact that it was low humidity meant that there was little water vapour in the air to act as a greenhouse gas. From a greenhouse perspective, we were left with a glimpse at what CO2 could achieve, ie., how much it brings to the table. The answer to the experiment was bug*er all. That night set a record low of -46 degC (ie., 227 deg K) which is below the blackbody temp of the Earth. This was notwithstanding approximately 390 ppm of CO2 in the atmosphere doing its best to heat the Earth below.
Of course, the weather had been cold for some time. On Wednesday it the high had been – 9 deg C, on Saturday, the high only managed -22 deg C. One can see from this when CO2 is left as being the only greenhouse gas (in practice it was not completely alone), it cannot prevent a drop off in temperature of up to 35 or so degrees. It is clear from this that the residency time of the CO2 ‘trapped’ IR is of short duration and when only CO2 is at work, in the real world, it provides little in the way of insulation/warming. I therefore consider it unlikely that if CO2 was significantly reduced “…it would be a heck of a lot cooler at night.” I consider that real life experience demonstartes that statement to be conjecture and unsupported and almost certainly wrong.
What keeps us warm during the night is the oceans and water vapour and clouds. It is likely that in the real world environment CO2 adds little to this and effectively contributes next to zilch.
The crux is the point made by AJB at February 20, 2011 at 10:16 pm:
“Until someone shows me otherwise, I maintain water rules the thermosphere – it’s a heat pump running at half throttle with a hunting governor (clouds) and a massive heat sink under it.” I fully concur with that.
Finally, whilst I have enjoyed reading your post (and others made by you) and not wishing to be rude, I would observe that what we need in this debate is not some physical analogy but rather some real observational atmosheric empirical data depicting the characteristics which CO2 is claimed to possess and produce.
There is one more fact that is being conveniently ignored in most discussions of the “greenhouse effect” and Earth’s thermal balance:
Large portion of the sunlight radiative energy reaching Earth is being absorbed by the plants and stored as chemical energy in organic compounds. When we release energy by burning coal, we release sunlight energy stored by the plants millions of years ago.
Where is this simple fact in “greenhouse effect” models?
Earth is not a black body. It is not a green house. It is a gigantic bio-technical solar panel exchanging heat with eternally moving and swirling air masses and oceanic currents while transforming Sun’s energy into the organically stored chemical energy, thus cooling itself and maintaining the thermal balance within a very wide range of changing variables such as insolation, atmospheric content of various gases, their vertical and geographic distribution, volcanic activity, cosmic radiation, magnetic phenomena, and thousands of other important factors not taken into account by using Boltzmann’s formula.
It doesn’t make sense to talk about “greenhouse effect” at all.
WOW, just WOW, a scale (including by the author’s own admission; springs and damping) to explain the absorption and reemission of electromagnetic radiation. I’m just shaking my head.
With respect, once the springs in the scale are compressed, “absorb the force from the ball” and have “reached equilibrium, thereby no further work is done” what pray tell causes the balls to be reemitted towards space?
Perhaps a better sequence would be:
A photon (visible) is absorbed and thereby ceases to exist
The temperature of the Earth rises (scale = +1)
A photon (IR) is emitted
The temperature of the Earth falls (scale = 0)
Somewhat less than ½ of the IR photon returns, the Earth warms (scale = +~1/2), A photon (IR) is emitted, the Earth cools (scale = 0)
Only if the photon can travel from Earth to the gases and back faster than the Earth can cool can your scale possibly show anything higher than zero after each sequence.
But of course we know that the Earth already cooled back to zero when the photon left the first time.
From a thermodynamic sense your scale has broken the laws, it cannot absorb, retain and also emit the same packet/quantum/photon of energy.
Cheers, Kevin.
“”””” Fred Souder says:
February 21, 2011 at 3:02 pm
Alan and Gary,
I should have said “radiative heat transfer” rather than radiation.
You are wrong here: The atoms do know what direction the radiation comes from. It has momentum. “””””
Well there is no such thing as “radiative heat transfer”, although people do use that term loosely, and quite incorrectly.
For a start “Heat” is a verb, and describes the process of storing energy in the kinetic motion of actual real physical matter; Ie atoms and molecules. Photons do NOT sore “heat energy”.
To the extent that once uses “heat” as a noun, it relates only to that mechanical energy of the motion of molecules, that are not at the absolute zero of Temperature. And we know the amount of that energy from the equipartition principle, that the average kinetic energy should be kT/2 for each degree of freedom for mechanical motion. since there are three translational axes, then we at least expect 3kT/2 for even a monatomic molecule like Argon. there can also be rotational modes that provide for even more energy storage; but the whole concept of “Tempertaure” and “heat (energy) are inextricably lionked by that nkT/2 relationship.
Photons on the other hand don’t have any understanding of Temperature whatsoever; they are a consequence of Maxwell’s equations for the Electromagnetic field, which also has NO Temperature input or knowledge.
And photons can go anywhere they please. photons emitted from the surface at Vostok Station while the Temeprature is close to -90 deg C, can propagate out into space (if they are lucky) and reach the back side of the moon, which is even colder than Vostok Station. Those very same photons at a different time, can miss the moon completely but proceed, covering the same 1/2 degree angular subtense until 93 million mile later they can reach the surface of the sun at about 6, 000 Kelvins.
They will land there and be received just as happily as they would be on the cold moon surface.
Electromagnetic radiation conveys radiant energy, in a manner that can be calculated from Maxwell’s equations (from the square of the electric field vector), or it can be represented by the h(nu) photon energy of quantum mechanics.
This constant insistence on applying thermodynamic principles or concepts, to systems that are NOT thermodynamic in nature; is part of what keeps “skeptics” branded as “ignorant fools”.
It’s not that more accurate information isn’t available; but there is continuous gaggle of folks who for one reason or another won’t take the time to learn a few basic concepts. You don’t have to know Quantum Chromo-Dynamics at your fingertips to understand the basic energy processes of weather and climate; and there are processes with thermodynamic properties and consequences, and also processes without thermodynamic consequences; such as EM radiation.
“”””” Phil. says:
February 21, 2011 at 1:07 pm
HenryP says:
February 21, 2011 at 11:21 am
Also, oxygen is a weak greenhouse gas as it also has a very weak absorption in the 14-15 um range.
It doesn’t, see here:
http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2N2O2.png “””””
Thanks for the very nice composite spectrum Phil. Can you describe what the assumptions are for these spectracalc computations. Are they computing some kind of intrinsic line width, for each different mode; or what are the presumed physical conditions of the sample. Does spectracalc allow one to determine broadened spectra from ambient Temperature (Doppler) and Collision (density) broadening ?
I get frustrated; when I see some CO2 or other “spectrum” and they say it was calculated to be at such and such wavenumber; but is observed somewhere else. That does not instill a lot of confidence in the calculation model.
I preume with what Astronomers dig up from their outer space laboratory; that we are somewhat better at the computation of a molecular spectrum than would deviate by 20% or more from some actual physical measured spectrum.
Unfortunately I do not have an open access to spectracalc; so thanks for posting such an informative plot.
commieBob says: February 21, 2011 at 4:09 pm
Thanks Bob. Of course radiation must eventually rule but the essence is in the detail. There is a lot going on above the tropopause that never seems to get much mention. Of late we’ve seen the business of the stratosphere becoming wetter, changing incidence of noctilucent clouds, thermosphere expansion/shrinkage, etc. (not to mention the mesopause anomaly, ionization, ozone, sprites, blue jets, and so on).
It would be really great if someone would put all this together and at least paint the bigger picture here on WUWT. What, for example, is the CO2 concentration trend in these regions and why is increased CO2 in the mesosphere reckoned to produce net cooling which isn’t AFAIK being observed? Any volunteers 🙂
Alexander Feht says:
February 21, 2011 at 2:50 pm
I never understood, how and why most of the models and explanations of the “greenhouse effect” don’t even touch upon the most fundamental fact — namely, that a very substantial portion of CO2 present in the atmosphere at any given time is absorbed by the plants, and chemically transformed into sugars, other carbon compounds, and oxygen, therefore removing the alleged “greenhouse gas” from the circulation (even if the “greenhouse” analogy could be used to explain, what is going on in the atmosphere physically, which is unlikely — for the simple reason, with very complex consequences, that the Earth’s atmosphere is NOT a greenhouse by any measure or analogy).
Only approximately half of the fossil fuel generated CO2 is sequestered each year, hence the annual increase in CO2 concentration in the atmosphere.
Moreover, the higher the concentration of CO2 in the atmosphere, the faster plants grow, and the larger is the volume of CO2 being absorbed and transformed.
The proportion sequestered remains fairly constant.
Moreover, any discussion of the published CO2 data is meaningless without mentioning that these figures are obtained downwind from the active volcano, in the vicinity of the volcano.
They aren’t.
Moreover, it has been mathematically and physically proved, several times, by many respected scientists, that CO2 ceases to act as the reflector of heat (infrared radiation) at concentrations above approximately 300 ppm.
Aside from the fact that CO2 doesn’t reflect IR no ‘respected scientist’ has proved anything of the sort, and it isn’t remotely close to being true.
The whole “greenhouse” analogy doesn’t hold water.
From your remarks above you don’t appear to know what the ‘greenhouse analogy’ is.
Stephen Fox, looks like you are the one!
Thought Ira might be the one to follow what I was trying to making so visual for him to follow step by step and to grow a bit in his view of radiative transfer within a real atmosphere but you seem to be the only one to grasp it. He really should read Miskolczi’s paper fror an astrophysicists viewpoint (two or three times).
Thanks for the mention.
My day this Monday turned out to be doublely good! ☺
Fred Souder says (February 21, 2011 at 3:02 pm): ” Again, radiative heat transfer ONLY occurs in the direction from a hot source to a cold source.”
Change that to net radiative transfer and I think just about everyone here would agree.
As written, however, the statement is incorrect.
George Smith,
Yes, there is such a thing as radiative heat transfer. Just like convective heat transfer, and like conductive heat transfer. It is not a term used loosely. It is what heats up Earth. It can be calculated. I am not getting why you say that it doesn’t exist. I understand everything else you wrote in your brief explanation of electromagnetic waves. Maybe I am using the vocabulary loosely?
Ira – long wave IR radiation from a body at an average of 15 °C as an all powerful and climate domineering radiation (and accompanying “back-radiation) is an AGW / CAGW or IPCC Think Tank invention and is the only possible explanation for how warming by GHGases can come about. – Over the years this GHG theory has changed so many times even Al Gore cannot keep up. – Every time a GHG theory flaw or fault appears, the theory changes. – The main flaw is still there thou, energy out cannot logically equal energy in. Energy in minus energy used i.e. “energy transformed” must equal energy out. That is a fact of nature Ira.
If your food intake just to stay alive is 1500 cal/day, then you will need more if you do any work. – The Earth’s various systems including the weather machine alone do a heck of a lot of more work than we ignorant little critters can even imagine. So cool down don’t do the IPCC’s work for them. It is up to them to convince the public the GH effect is real. – The Earth’s, temperature is mainly dependent on 3 things and radiation is not one of them:
1) Energy input from the Sun or the force-factor of the “Solar Constant”
2) Atmospheric pressure / Adiabatic Lapse Rate
3) The ability of water vapour to make cloud formations.
The fact that air movements are mainly near horizontal rather than vertical slows down the adiabatic lapse rate considerably thus keeping the air molecules closer together for longer – It is also likely that temperatures would be cooler without Water Vapour. But as descending “dry air” must warm at a higher rate than ascending “wet air” cools, who knows what the average will work out at? – However having said that there must be water vapour in order to have clouds and they shade the surface as well as reflect the sunlight back to space, so without them, but with water vapour still in place would this maybe be a much warmer Earth?
Remember we are talking about an acquired “Global” temperature that is higher than what can be produced by the actual energy input by the Sun alone. A puny bit of CO2 and a weak bit of IR radiation is not necessarily needed for that at all.
And as for “Willis Eschenbach’s excellent People Living in Glass Planets” – It was strange how the workings out of “The Natural Greenhouse Effect” added up exactly to what the temperatures are today. Yet we know there have been periods when the Earth has been much warmer and also much colder than today! And the mathematics used is unchangeable. So something is wrong with something Ira.
I’ve always believed, and have heard repeated here several times, that heat only travels from relative warm to relative cold. But this entire discussion has brought to mind the fact that heat, when you come down to it, is also random. Now while absolute zero has absolutely no heat, anything above that must be radiating some kind of heat.
Why should it only go in one direction?
I can see how the effect would tend to be directional. The amount of heat that the “warmer” area receives from the “colder” area would be far less than the amount of heat the “colder” area receives from the “warmer.” But the claim that it can only go in one direction puzzles me. Now. It didn’t before.
Free and open discussions are dangerous. They hurt my thinker thing.
RichardSmith;
Blograge! I knew you’d like that question…>>>
I did. I answered it.
As well as some of your other comments.
And the best you’ve done in response is accuse me of being angry.
Oh wait…. there was also that encyclopaedia you wrote explaining how I’d misquoted you. Why bother since you already know it will just disapear from view?
If you are actually a skeptic (as I am) then put some effort into debating the issues instead of obfuscating them.
WOW, just WOW again;
“there are processes with thermodynamic properties and consequences, and also processes without thermodynamic consequences; such as EM radiation.”
Boy I sure wish I knew 4 decades ago that EM radiation did not have to follow the rules of thermodynamics. I could be a whole lot richer than Warren Buffet by now. (slapping head repeatedly….)
For anybody that has any doubts, all physical processes (as we currently understand them) have thermodynamic “consequences”. Last I checked EM radiation DOES NOT HAVE A WAIVER, it might have one now, but I DOUBT IT.
Cheers, Kevin.
So, Ira, back to you.
You say “The Sun energy coming in is in the visual and near-visual (shortwave) bands, where the Atmosphere is all but transparent. The absorption spectum for GHGs has a “window” for that light energy, so it whizzes right through, just the way a police car can buzz through a red light or stop sign in an emergency.
The Earth energy going out is in the far infrared (longwave) “heat” bands, where the Atmosphere is mostly not transparent. The absorption spectrum for GHGs is effective for that heat energy, so it has to stop, as you do for a red light or a stop sign.
The reason the Sun’s light energy is in the shortwave range is that it is something like what scientists call a “blackbody” at around 5500ºK, which is really hot. The reason the Earth’s radiation is in the longwave range is that the Earth is something like a “blackbody” at 210ºK to 310ºK, which is lot cooler than the Sun, fortunately for us living beings.
The reason GHGs act that way has to do with the atomic structure of their molecules. Water vapor (H2O) is by far the most effective GHG, covering much of the radiation spectrum, particularly about two-thirds of the spectrum where Earth outputs longwave radiation, but it has a convenient “window” for UV and visible light, and some infrared. Carbon dioxide (CO2) is mostly transparent to radiation, but it has a few absorption bands, the most important of which is around 12μ to 17μ, in the range where the Earth outputs longwave radiation. Other GHGs are oxygen (O2), ozone (O3), nitrous oxide (NO), and methane (CH4), but they have relatively narrow absorption bands in the range where the Earth outputs longwave radiation. The majority of the Atmosphere consists of Nitrogen (N) that is transparent to all radiation in the bands of interest. I hope this clears things up for you.”
So, in other words, no longwave energy is coming into the Earth’s atmosphere. That only comes up from the Earth? The Sun does not emit infrared waves? And here I’ve been laboring under the idea that the Sun emits radition in every wavelength. And waves of every temperature are constantly bombarding the Earth’s atmosphere. So, in your scenario it’s impossible for entering waves to “consume” the “free” CO2 and other “free” gases before they are consumed by radiated “greenhouse” heat. And the Earth gets hotter and hotter. Until we all burn. No way out.
Baloney.
I am sorry to say that you (the author) are severely lack of fundamental knowledge of radiative heat transfer (such as mie scattering or rayleigh scattering), so are those lousy GHG warmer or scientist
how does 6μ to 20μ wavelength of radiative heat energy being absorbed, scattered, diffused what ever mechanism you can invent, by 400 ppm volumetric density of CO2 with molecule size of 3.2 Angstrom, which means your purple ball size is ~ 1/3000 of your sun light yellow ball at atomspheric temperature of 15 C ?
If CO2 is blanket over the earth like Venus, then I am sure the conductivity and heat capacity of CO2 is more of issue. But you can not say this to our 400PPM or even 1000 PPM level of CO2 on earth
A PHD in heat transfer and thermal fluid science
Does this explanation describe the process in an actual greenhouse? How does the greenhouse heating differ from the heating in a closed car?
My argument is one of semantics and the selection of GHG heating of the atmosphere by the atmospheric trace gas (ATG) CO2 as a propaganda ploy, by the IPCC, to take advantage of the general public’s naiveté about things scientific.
The explanation stresses the dynamic nature of radiation absorption and re-radiation.
The atmosphere is essentially opaque to the Sun’s radiation in the absorption bands of CO2, with an atmospheric CO2 concentration of approximately 200 ppmv.
The claim is that the radiation absorbed by the Earth of all wave-lengths and re-radiated as though from a black-body at a temperature of 33 degrees Centigrade is slowed by being absorbed and re-radiated in the manner previously mentioned and the higher the CO2 concentration, the slower the trip to space. Convection undoubtedly gives the trip a boost.
WHAT I LEFT OUT OF THE PHYSICAL ANALOGY
My physical analogy addresses only radiative energy transfer. In the real-world, energy transfer from the Sun to Earth and Earth to Space is purely radiative. However, the Earth transfers a considerable amount of energy to the Atmosphere via convection and conduction, in the form of winds, precipitation, thunderstorms, etc. These effects are absent from my analogy.
When you have convection and conduction, you don’t have a greenhouse effect unless you re-define greenhouse.
I suppose the black body temperature of 33 degrees Centigrade is an average, because the black body temperatures at the poles, the equator and points in between differ.
The black body temperature of 33 degrees Centigrade is fortuitous, being in the center of the CO2 absorption band, and all.
All the gases in the atmosphere are capable of absorbing energy, if not by radiation, then by collision.
Lots of broken lances lying around the chaotic wind-mill called Nature.
——————————————————————————————————————
DocMartyn says:
February 20, 2011 at 5:13 pm
human beings are very smart, they can take any piece of scientific knowledge and turn it into technology, so not has no one used the CO2 green house effect for anything? Why don’t we replace the vacuum in Dewer flasks with CO2? Why don’t we fill greenhouses with CO2? Why are not the wall spaces and pairs of glass panes in houses filled with CO2?
Why does no one used this CO2 ‘trick’ as a force for good?
———————————
Commercial growers sometimes increase CO2 concentrations in greenhouses to 1000 ppmv to obtain rapid and luxuriant growth.
I have not seen any data on the effect of this change in CO2 concentration on temperature in the greenhouse.
Oh, just one more observation;
Someone posted that;
“This constant insistence on applying thermodynamic principles or concepts, to systems that are NOT thermodynamic in nature; is part of what keeps “skeptics” branded as “ignorant fools”.”
Please note that; ALL SYSTEMS ARE THERMODYNAMIC IN NATURE. Please read that statement two or three or four times if necessary, once you can provide any proof that the laws of thermodynamics DO NOT APPLY to EM radiation please post this information. Thank You.
Those of you that insist that the laws of Thermodynamics do not apply to EM radiation are increasingly looking like the “ignorant fools”.
Please note that I have several Masters Degrees including intensive study of Maxwell’s laws and the Optical aspects of radiation moving through systems. Along with many decades of practical engineering experience measuring and analyzing EM (Visible thru RF) radiation. Never Ever have I heard that the laws of thermodynamics do not apply to EM radiation. Please cite any reference (outside of the climate science world please) that makes and proves this contention.
I apologize in advance for the “nasty” nature of this post, but I do not consider myself (an avowed AGW denier) an “ignorant fool”. We might respectfully disagree about the actual effects of IR radiation returning to the Earth’s surface from “GHG’s” but I will not be dismissed by being told the that Laws of Thermodynamics “DO NOT APPLY”
Cheers, Kevin.
George E. Smith says:
February 21, 2011 at 5:08 pm
“”””” Phil. says:
February 21, 2011 at 1:07 pm
HenryP says:
February 21, 2011 at 11:21 am
Also, oxygen is a weak greenhouse gas as it also has a very weak absorption in the 14-15 um range.
It doesn’t, see here:
http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2N2O2.png “””””
Thanks for the very nice composite spectrum Phil. Can you describe what the assumptions are for these spectracalc computations. Are they computing some kind of intrinsic line width, for each different mode; or what are the presumed physical conditions of the sample. Does spectracalc allow one to determine broadened spectra from ambient Temperature (Doppler) and Collision (density) broadening ?
No problem George, basically it’s the HITRAN database, in this format each line is represented as a thin line, if you want to do a high resolution calculation over a smaller wavelength range then you can take account of the broadening. I left out the H2O spectrum, which dominates in the 4-8μm region, for clarity.
I would want to see the OLR in the CO2 absorption bands in April, and then August, over Siberia and Canada:
p.s. I thought a string vest would only keep you warm if you put something over it.
Alexander Feht says:
The whole “greenhouse” analogy doesn’t hold water.
———————
Alexander you must be a charter member of the Green-House Effect Club.
Phil. says:
February 21, 2011 at 5:42 pm
Only approximately half of the fossil fuel generated CO2 is sequestered each year, hence the annual increase in CO2 concentration in the atmosphere.
Nobody knows, what proportion of the “fossil fuel generated CO2” is “sequestered” by plants, exactly (all existing “estimates” are willful fantasies). There is no logical connection between this proportion and the alleged annual increase in CO2 concentration in the atmosphere, since the nature of this increase is unknown, and the data is manipulated.
The proportion sequestered remains fairly constant.
Again, this is a pure speculation.
[Moreover, any discussion of the published CO2 data is meaningless without mentioning that these figures are obtained downwind from the active volcano, in the vicinity of the volcano.]
They aren’t.
Yes, they are.
[Moreover, it has been mathematically and physically proved, several times, by many respected scientists, that CO2 ceases to act as the reflector of heat (infrared radiation) at concentrations above approximately 300 ppm.]
Aside from the fact that CO2 doesn’t reflect IR no ‘respected scientist’ has proved anything of the sort, and it isn’t remotely close to being true.
As Jim Macdonald already mentioned above, “due to the efficiency of CO2 in absorbing IR radiation, and using Beer’s law, Professor James Barrante and others have calculated that half the available IR is absorbed by as little as 80 ppm. After that less and less IR is available as it is depleted logarithmically by additional CO2, until most all is gone by the time CO2 reaches 250-300 ppm. Little more warming can occur.”
From your remarks above you don’t appear to know what the ‘greenhouse analogy’ is.
To you, maybe, since from your remarks it appears that you know it all. Other people are not so conceited.
Albert, very good points! The gravity meter at my head on Earth will read a little less than the one at my feet because my head is a bit further from the center of mass of the Earth. Therefore, the guy in the sealed elevator would be able to differentiate between being in a fixed position on the surface of the Earth versus being accellerated in Space far from any mass. You are correct.
What, however, does this have to say about the truth value of Einstein’s theory of relativity? I would say that Einstein used the elevator idea to spark his insight that gravity and accelleration were equivalent. Just as my physical analogy of the atmospheric “greenhouse” effect is a simplified version of the truth of how GHGs help warm the Earth, and (as I point out in the last section) leave out a bunch of important details (convection, etc.), Einstein’s elevator man analogy captures a nugget of truth, while missing a relatively minor, and easily explained, caveat.
As for your and others comments that the atmospheric “greenhouse” effect is very different from a physical greenhouse, I refer you to the very first image in this post which shows a physical greenhouse and has under it the following words: “…The greenhouse effect and a real greenhouse are similar in that they both limit the rate of thermal energy flowing out of the system, but the mechanisms by which heat is retained are different. A greenhouse works primarily by preventing absorbed heat from leaving the structure through convection, i.e. sensible heat transport. The greenhouse effect heats the earth because greenhouse gases absorb outgoing radiative energy and re-emit some of it back towards earth….”
In addition, in my graphics and much of my test, I use “scare quotes” around the word “greenhouse” and call it the “atmospheric ‘greenhouse effect'” to point out the difference. Whether you or I like it or not, we (society in general) are stuck with the use of the word “greenhouse” and “greenhouse gases (GHG)” when refering to the atmospheric effect. If WUWT used a different term, who would know what we were talking about?
Re: Alexander Feht (February 21, 2011 at 7:37 pm), atmospheric CO2 is measured at a number of surface locations, including Mauna Loa and the south pole. All agree within a few ppm. As measured by satellites, CO2 varies within about 10 ppm worldwide.
Gary Hladik,
You think I don’t know that?
The only continuous record of atmospheric CO2 concentration that spans at least several decades, however, is from Mauna Loa. The methods used to produce this record, and the environment in which it has been produced, are suspect.
It is this record that is being almost invariably given by the proponents of the AGW hypothesis as a “proof” of anthropogenic influence on climate. It proves nothing of the sort.
The only thing we know for certain is that the modern atmospheric CO2 concentration is much lower than it has been most of the time, on geological scale, and that its current slight increase is well within the extreme lower range of its normal fluctuation.
Natural mechanisms influencing this parameter are poorly understood; most probably, the current change of CO2 concentration has something to do with the Earth’s gradual coming out of the Ice Age.
Even if human activity contributes some small part of this increase, there is no evidence that this most useful, life-giving trace gas can produce a statistically significant “greenhouse” effect.
Rather, it has been convincingly shown that its increase in the atmosphere follows, not precedes, periods of warming on a large time-scale, and is completely disconnected from temperature changes (as it is right now) on smaller, decades-long time-scales.
Alexander Feht says:
February 21, 2011 at 7:37 pm
Phil. says:
February 21, 2011 at 5:42 pm
“Only approximately half of the fossil fuel generated CO2 is sequestered each year, hence the annual increase in CO2 concentration in the atmosphere.”
Nobody knows, what proportion of the “fossil fuel generated CO2″ is “sequestered” by plants, exactly (all existing “estimates” are willful fantasies). There is no logical connection between this proportion and the alleged annual increase in CO2 concentration in the atmosphere, since the nature of this increase is unknown, and the data is manipulated.
“The proportion sequestered remains fairly constant.”
Again, this is a pure speculation.
Not at all, perhaps you should try reading this?
http://radioviceonline.com/wp-content/uploads/2009/11/knorr2009_co2_sequestration.pdf
[Moreover, any discussion of the published CO2 data is meaningless without mentioning that these figures are obtained downwind from the active volcano, in the vicinity of the volcano.]
“They aren’t.”
Yes, they are.
Presumably you refer to Mauna Loa, in which case you’re wrong since data taken when there is a wind from the direction of the volcano aren’t used in compiling the statistics. Of course the CO2 levels are also determined at other locations such as the South Pole which agree well with ML.
http://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html
[Moreover, it has been mathematically and physically proved, several times, by many respected scientists, that CO2 ceases to act as the reflector of heat (infrared radiation) at concentrations above approximately 300 ppm.]
“Aside from the fact that CO2 doesn’t reflect IR no ‘respected scientist’ has proved anything of the sort, and it isn’t remotely close to being true.”
As Jim Macdonald already mentioned above, “due to the efficiency of CO2 in absorbing IR radiation, and using Beer’s law, Professor James Barrante and others have calculated that half the available IR is absorbed by as little as 80 ppm. After that less and less IR is available as it is depleted logarithmically by additional CO2, until most all is gone by the time CO2 reaches 250-300 ppm. Little more warming can occur.”
Well he’s made a flawed calculation then, it is an approximately logarithmic dependence but it certainly is no where near ‘all gone’ by 250 ppm, and he would need more than Beer’s Law to calculate it. Perhaps you’d like to give a citation to his calculation?
See here:
http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2spectra-1.gif
Frank Lee MeiDere says:
February 21, 2011 at 6:13 pm
“Why should it only go in one direction?
I can see how the effect would tend to be directional. The amount of heat that the “warmer” area receives from the “colder” area would be far less than the amount of heat the “colder” area receives from the “warmer.” But the claim that it can only go in one direction puzzles me. Now. It didn’t before.”
——————————–
Does it seem reasonable to you that you could, while driving in your car, go a little slower and a lot faster at the same time? Now imagine you and your car are the average of all the molecules in a whole bunch of molecules. Heat is about motion.
Henry@Phil. & others
If you carefully study the atmospheric absorption bands you will see that oxygen/ozone does show some absorption in the 14-15 um range.
In fact, all so-called GHG’s show radiative cooling being caused (due to deflection of sunlight at various wavelengths in the 0-5 um range) as well as some radiative warming (due to the entrapment of earth’s radiation at varying wavelengths between 4-15 um).
I believe we had this argument before.
The question has always been: what is the net effect of an increase/decrease of the relevant GHG’s at the relevant concentration range in the atmosphere? Unless we have some actual test results on this, all talk here and all theories and analogies about the greenhouse gas effect is pretty much a waste of time.
In addition, more CO2 is beneficial for earth as it stimulates growth by taking part in the photo synthesis. In its turn more greenery leads to more cooling. Did you ever see much forest growth at higher altitudes and latitudes where is is very cold? Observe in Africa, if you enter the forest at night or just before dawn. You can feel it is cooler inside the forest. So more greenery (caused by more CO2) causes cooling.
So Phil.,
if you want to help us all, and win the argument, why don’t tell us exactly, how much warming and how much cooling is caused by an increase in CO2 of only 0.01% (over the past 50 years)? I really would like to see those results. In the right SI units. Where are they?
So if you don’t have those results, all talk is useless.
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Phil,
Links to designedly “friendly” sites prove nothing but the weakness of your position.
The Mauna Loa record and Keeling’s methods were criticized so much and for so long that it makes no sense for me to continue this argument.
You would excuse me if I find no pleasure in conversing with people who initially insult their opponent by assuming that he or she knows nothing, and then, realizing that they’ve blundered, scramble to justify their hasty and rude attitude by searching the Web for a couple of links that would agree with their unfounded statements.
Re. Kevin @ February 21, 2011 at 4:45 pm
I buy your reasoning 100%, (especially after reading your “nasty” post).
However, your model has the earth at 0 K as an implied assumption. If the earth is above 0 K, it will emit a photon right after the first one, and a third after that and so on. When the first photon returns through reflection or from being emitted from a second body, the earth will be cooler than when no. 1 left. That makes it possible for no. 1 to heat the earth even though it was first released from the same earth. This is consistent with the second law, as I see it.
I would very much like to hear your opinion on this. Thanks. /Dan
I appreciate the effort, Oliver, but I can drive faster or slower in any direction. I’m still not understanding why heat transference can only be in one direction.
Just a note to all when discussing the ‘absorption’ bands.
re Transmissivity
People make a fundamental mistake when they show graphs with ‘transmissivity’ or ‘transmission’ bands.
NDIR gas analysis equipment does NOT measure ‘transmissivity’.
NDIR gas analysis equipment measures the absorption or absorptivity component, only. PERIOD
This is important to keep in mind.
Graphs showing ‘transmissivity’ are incorrectly labeled. They should be correctly labeled ‘transmissivity and reflectivity’ on the y-axis.
All real world molecules have absorption, transmission, AND REFLECTION of incoming photons. A photon striking a molecule can either go through it (transmissivity), bounce off it (reflectivity), or be completely absorbed by it (absorptivity).
3 possibilities. Not 2.
In addition, all 3 of those possibilities are angularly dependent. All three of those components VARY dependent on the angle with which the photon strikes the molecule.
That always applies to any real world material. Only a true ‘blackbody’ has 100% absorption at all wavelengths, and all angles. And they don’t exist in the real world, even at the molecular level.
NDIR gas analysers and other spectral devices are not designed to measure REFLECTION or TRANSMISSION, just absorption.
The reflections (reflectivity) properties contribute to the bouncing around of all molecules, even N2. For example, the reflectivity of N2 is not known for long wavelengths. It has not been studied and accurately quantified over a wide number of wavelengths. There is much that has not been correctly quantified for properties in the long wavelengths.
That aspect of thermal radiation effects has never been studied because the measurements are very difficult to make.
Take all graphs, etc generated from HITRAN and others with a LARGE grain of salt, especially for the long wavelengths.
All the visual example that show a CO2 layer around the earth are wrong.
These images show that in some altitude there is a layer of CO2 like the clouds. WRONG.
The CO2 exist from the ground up with more or less the same amount of CO2 to the altitude of about 100KM (homosphere according Britannica). Actually, there is even more CO2 above the 100KM homosphere.
This means that visible light has to go through a 100KM thick layer of CO2 to reach the ground.
Can you imagen a 100KM thick layer of CO2 atoms.
At least some of the yellow balls have to avoid every CO2 atom to reach the ground to create some heat down here.
At least some of the purple ball have to avoid every CO2 atom to get out of the earth atmosphere or the planet will overheat.
All that is needed is to add heat carried upwards past the denser atmosphere (and most CO2) by convection and the latent heat from water changing state (the majority of heat transport to the tropopause), the albedo effects of clouds, the inability of long wave ‘downwelling’ (the blue balls) to warm water that makes up 2/3rds of the Earth’s surface, and that due to huge differences in enthalpy dry air takes far less energy to warm than humid air so temperature is not a measure of atmospheric heat content.
What is demonstrated here (and by the deep discussions) is the over concentration on simplistic radiative energy transfer. And the people involved wonder why the results of the radiative equations (to many places of decimals) with simple parameterized clouds (that only have a radiative effect) have no relationship to the ‘real world’?
What a really great post! Many thanks indeed. It’s clarified a great deal for me. Also, thanks for the comment about Einstein and physical analogies. I decided that serious math was beyond me way back at age 16 when, after our university entrance exams (in Scotland, where they used to do things sooner), the maths teacher filled the final days of term taking us into some university-level maths. It was when we got to double integration of compound trig functions that I realised that I’d never make a mathematician – ‘cos I couldn’t build a mental model of what the heck was going on. Bad decision – but wot the heck archy, toujours gai, toujours gai.
Alexander Feht says:
February 21, 2011 at 11:49 pm
Phil,
Links to designedly “friendly” sites prove nothing but the weakness of your position.
Whereas your position is backed by nothing just your unsupported assertion.
The Mauna Loa record and Keeling’s methods were criticized so much and for so long that it makes no sense for me to continue this argument.
Not by anyone who knows the subject, and the CO2 data does not rest on ML alone as has been pointed out to you.
You would excuse me if I find no pleasure in conversing with people who initially insult their opponent by assuming that he or she knows nothing, and then, realizing that they’ve blundered, scramble to justify their hasty and rude attitude by searching the Web for a couple of links that would agree with their unfounded statements.
I made no such assumption, I addressed your incorrect assertions, I didn’t need to search the web for any links. Your failure to address any of the points speaks volumes.
Nice post, but I think a better physical analogy for CO2’s atmospheric warming ability is as “a very thin, gaseous mirror.” There is no actual surface to this mirror (or to the “greenhouse”), there is only a thin gas which randomly reflects some small amounts of light in all directions equally, and lets the rest pass through. The end product is a diffusion of IR light which increases the residence time of this energy in the atmosphere. And in the midst of this, the whole process is controlled by a complex vapor-water-cycle that is far more powerful than the contribution CO2 makes.
Another remark that I want to post here is that despite the increases in GHG’s during the past 40 or 50 years there has not een any causal link that I could find between that increase and the actual warming of the planet.
Namely, if GHG’s were to blame for the warming noticed during the past 150 years, or even be partly responsible therefore, you would expect minimum temperatures to rise, in line with modern warming or even in line with the increase in maximum temperatures observed. What I find is exactly the opposite. e.g. minimum temps have declined or stayed the same.
see here:
http://www.letterdash.com/HenryP/assessment-of-global-warming-and-global-warming-caused-by-greenhouse-forcings-in-pretoria-south-africa
ergo. this post and this whole debate is a waste of time…
Unless somebody has other test results than I have?
To HenryP
I agree with you.
The Tmin data have the least amount of ‘atmospheric noise’ as well as ‘solar noise’ (and political ranting and raving noise!).
They are the clearest signals.
And all the Tmin data I seem to find, show stable or decreasing temps over the past 50 to 60 years.
Since I get named explicitly in this article, I suppose I really have to respond to it.
My basic issue is that you absolutely can not double count energy input.
There is one dominant source of energy to warm the Earth, and that is the sun.
It provides a relatively constant number of Joules of energy input to the Earth, and that alone is responsible for raising the temperature of the Earth.
It should also be remembered that heat transfer by radiation amounts to excitation of a molecule to a higher state of energy. When that molecule “relaxes” it emits a photon equal in energy to the state change.
That photon can ONLY excite another molecule if the molecule is at a lower energy state, AND it next highest state is equal to or less than the energy contained in the photon.
Since the energy that excited a CO2 or H2O molecule in the atmosphere originated from the Earth, and that Earth is likely warmer (at a higher energy state) than the photon, the photon will not cause any further excitation of molecules on the Earth’s surface, and hence increase its temperature.
In other words, heat transfer by radiation only works in one direction, from the hotter body to the cooler body. Never the other way around.
Example – shine as many 100W bulbs as you want at the Sun, but you will never increase its surface temperature that way.
One modification to the above though. If the warmer air moves (a long way) so that it is over an area much cooler than the area that caused its original warming, then some back-flow is possible (and likely).
However, also consider that warmer air will tend to convect upwards, taking it closer to the outer atmosphere from which outwards radiation takes place. Also, as it moves further from the surface of the Earth, there are many more molecules between it and the Earth which will intercept those photons.
But this is NOT new energy. It is energy that has already been accounted for and should NOT be re-counted.
Domenic says:
http://wattsupwiththat.com/2011/02/20/visualizing-the-greenhouse-effect-a-physical-analogy/#comment-604786
Thank you Domenic!
I did a similar investigation in La Paz, Bolivia (June & July from 1974).
I found exactly the same as in Pretoria.
I already mentioned Spain and Northern Ireland here as well:
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Put your results together with mine and we find: minimum temps have not been increasing in line with modern warming. The increases in GHG’s of the past decades do nothing whatsoever in keeping earth a bit warmer.
That is why I am saying: more carbon dioxide is good for the environment as it stimulates growth of greenery (photo-synthesis) and susequently also that of all animal life.
Professor Johnsons view of it all;
http://www.csc.kth.se/~cgjoh/blackbodyslayer.pdf
Frank Lee Meidere says:
February 22, 2011 at 12:14 am
Oliver Ramsay says:
February 21, 2011 at 10:25 pm
I appreciate the effort, Oliver, but I can drive faster or slower in any direction. I’m still not understanding why heat transference can only be in one direction.
———————————————-
Not at the same time, you can’t!
The more furiously that particles are charging around and crashing into one another, the more heat there is in that bunch of particles. That’s a description, not a cause and effect.
A colder thing radiates energy, not heat, to a hotter thing with nary a care. The hotter thing absorbs what it is sent, but it doesn’t become heat because it doesn’t result in the average frenetic motion of all those particles becoming more frenetic. (This was my car analogy; you can’t be both more frenetic and less frenetic at the same time) Two adjacent objects will happily radiate back and forth, but the hotter will radiate much more energetically than the cooler, such that the cooler can never heat the warmer by throwing photons at it, ‘cos they’ll just get thrown right back (or elsewhere) at a rate that is proportional to the fourth power of the temperature.
Radiation is not transfer of heat. It is transfer of energy. Heat is the kinetic energy of a volume of particles, not just one. At any moment, in a chaotic soup of particles colliding with one another, each one will have its own speed. The temperature is the average speed of all the particles.
The presence of the cooler object influences the rate at which the warmer body cools, just as the warmer body influences the rate of warming of the cooler body. However, the cooler body cannot make the warmer body warmer than it was before. In one’s imagination, it can make the warmer body warmer than it hypothetically would have been, in the absence of the cooler body.
One scenario describes a physical process, the other an imaginary state of affairs, which is initially helpful in visualizing but later distracts.
Imho, the CO2 backradiation story is the weaving of the “warmer than it otherwise would have been” into what actually happens, with a concomitant creation of energy “out of thin air”, if you’ll forgive me.
“”””” Fred Souder says:
February 21, 2011 at 6:01 pm
George Smith,
Yes, there is such a thing as radiative heat transfer. Just like convective heat transfer, and like conductive heat transfer. It is not a term used loosely. It is what heats up Earth. It can be calculated. I am not getting why you say that it doesn’t exist. I understand everything else you wrote in your brief explanation of electromagnetic waves. Maybe I am using the vocabulary loosely? “””””
Well Fred, that is precisely the problem, you ARE using the vocabulary loosely. And I say that not in any critical or derogatory manner.
One of the unfortunate things about the study of science (any science; not just Physics) is that we have many words which have perfectly ordinary every day common lay usage; but those words MAY also have a very specific and NOT substitutable scientific technical meaning. And misuse of terms with specific scientific meaning, will simply convey false impressions.
A good example, is the word “Brightness” when referring to some source of light; but also used in referring to things that aren’t at all visible (like an infra-red, or even a microwave source.) Particle accelerator engineers and scientists talk about the “brightness” of their particle sources.
It turns out that Photometry is one of the most screwee up areas of physics, and an easy one to miscommunicate in. A lay person, might reasonable say that “The sun is very bright today”; or perhaps, “my desk top isn’t nearly as bright as I would like” “I need to get a brighter lamp to illuminate my desk more brightly.”
To the scientist, some of those usages of the word bright or brightness, are not even measured in the same units; so they clearly can’t be referring to the same things. So we DECRY the use of the word bright or brightness, when talking about light sources (or IR ones) in a scientific context.
So we can more pedantically say that the sun has a high “Radiance” or a high “(radiant) Intensity”; which are energy related terms; or photometrically, we would say it has a high “luminance” or a high “(luminous) Intensity” Those are quite different terms with different units. Radiance (luminace) is measured in Watts per square metre, per steradian (lumens per square metre, per steradian). Radiant (luminous) Intensity, is simply Watts per steradian (lumens per steradian); from an assumed point source. With light that’s a fancy term for candlepower.
We can also talk about Watts (lumens) per metre squared which would be Radiant (luminous) emittance.
When it gets down to the desk surface, it is still Watts (lumens) per square metre, but we now call it “Irradiance (illuminance).
So back to your “RADIATIVE HEAT TRANSFER”.
Now there isn’t any (well much) MATTER between the sun, and the earth; so there is no mechanism by which “Heat” can be transferred fromt he sun to the earth or vice versa, since “Heat” is a property of real physical matter; not of photons which are also elecromagnetic waves.
ENERGY however CAN be transported from the sun to the earth, and also the other way, by means of EM RADIATION, which is either an EM wave, or a stream of photons; your choice. The transport is of ENERGY, not of HEAT.
That energy could be subsequently converted into heat by some mechanism that absorbs the energy; but it doesn’t have to be. for example, if the radiant energy from the sun is in an appropriate wavelength range, it can be absorbed by some semiconducting material and converted into an electric current, instead of being converted directly into heat.
The critical issue, is that the photons; or the elctromagnetic waves can go any darn place they fancy; although they can be absorbed if they encounter matter; but they can transport across empty space (vaccuum) from a very cold place to a very hot place with impunity; including travelling from Vostok Station to the surface of the sun. EM fields or photons do not even know what Temperature is; that is a property of real physical matter; made up from atoms of some of the 92 (naturally)known elements. Sans atoms; there can be no heat.
It would help if people used “heat energy”, when referring to heat as if it was a noun, whereas some of us prefer to think of heat as a process, so it is a verb, meaning to raise the kinetic energy of random motion of atoms, and molecules.
And when I said that “Skeptics” get branded as “ignorant fools”, that was NOT my sentiment; that was the perception of the AGW crowd. And that is why I try to get the community here to understand the disticntion between “radiant energy”, and “heat energy”
The transport of the latter is restricted by the second law of thermodynamics; the former is not; which is why I also said that photons and electromagnetic fields are not part of thermodynamics.
We do know that EM theory reuires that any (material) body that is at a Temperature above absolute zero can radiate a thermal EM spectrum of radiant energy. In a closed isothermal cavity, that is in thermal equilibrium, there will be a well understood density of electromagnetic radiation (energy), whose source of energy, is whatever maintains the Surface Temperature of that cavity. The radiation itself is quite oblivious to the Temperature of the cavity walls.
Suppose for the sake of discussion, that there is ONE point on the inside of that surface, that is one degree C lower in temperature than every other point on the surface. That point must also be radiating EM radiation, just slightly lower in radiant emittance, than the rest of the cavity wall; and that wall is totally absorbing everywhere.
What on earth happens to the photons emitted from our colder spot; if as some suggest, they can go nowhere else, since everywhere else is at a higher Temeprature ?
Well fortunately those photons, have no idea whatsoever what the wall temperature is so they simply cross the cavity and get absorbed wherever they land. How easy is that to understand.
And skeptics and lay folks need to understand the difference, and the difference in the technical terminology; if they wish to avoid that “ignorant fools” label the AGW crowd wants to brand them with. I’m just trying to help folks understand.
As I skim through the replies and questions Ira sparked, I sometimes scratch my head at the number of questions that are asked but are actually answered in the article, the slew of criticisms on points that the analogy was clearly never designed for, and arguments about cold things not being able to heat warm things, one that I see coming up in almost every thread over and over and over, plus a few others.
1. The physical model isn’t designed to explain how CO2 interacts in the atmosphere over all. The model was designed to illustrate one single characteristic of CO2, that being how it reacts with long wave radiation in the context of the “greenhouse effect”. It does a pretty good job of that. Expecting it also explain thermal quenching, convection, etc is silly. It wasn’t a model of the atmosphere that was proposed, it was a model of how CO2 interacts with long wave, and that’s it. Its like building a model of a car to test in a wind tunnel. It tells you nothing about the car’s horsepower, and it wasn’t supposed to.
2. This cold things can’t send heat to warm things argument never seems to end. The amount of heat any given object radiates is well known and easily determined. The caculus to arrive at the final equations is complex, but the equations themselves are easily understood by anyone with high school math. Here’s a couple of decent explanations:
http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
http://www.egglescliffe.org.uk/physics/astronomy/blackbody/bbody.html
The point being that the temperature of the surroundings has NOTHING to do with the calculation. Any body emmits heat or energy flux as photons, and those photons travel at the speed of light until they hit something. The photons neither know nor care if what they are hitting is warmer or colder than where they came from. The amount of heat radiated by the warm body is much higher than the amount of heat radiated by the cold body, so obviously if there are no other factors, the warm body cools and the cold body warms. But remove the cold body, and the photons it was emitting that were being absorbed by the warm body go away with it. So the warm body is still cooling, but it has no off setting photons from the cold body, so it cools faster. What did the early settlers use to insulate their houses in the depths of winter? Answer: SNOW!
3. Why don’t we use CO2 to heat greenhouses or insulate houses if it does what is claimed? I love this question because of all the ridiculous answers it generates arguing over what it would or would not do. The answer is in part that greenhouses heat up because the prevent heat loss via convection, but that still leaves why not use CO2 for other applications to retain heat? The answer is because CO2 is a pretty lousy insulator and there’s tons of materials on the market that do a far better job in a far smaller form factor, and are practical to install and maintain. Trying to compare what a few inches of CO2 could do for a building compared to thousands of meters of atmosphere is just silly.
That must be why double stars disappear. They keep heating each other up until they get so hot they just explode.
Amazing. Utterly amazing.
Glickstein’s explanation of the “greenhouse effect” is nothing more than the “ballgame” version of the simplistic notion that radiation streams affect the temperature of all matter–gaseous, liquid, or solid–in the same way that they would a blackbody. And it perpetuates the rampant confusion between local radiative intensity and thermal energy transfer. It is only in space that the two can be equated.
What such pseudophysical, radiation-only explanations totally miss is differential thermalization of various substances through all the other means of thermal energy transfer: conduction, convection, and–most importantly on a largely oceanic planet–evaporation. Scores of careful energy transfer eperiments around the globe have repeatedly shown that moist convection is the principal means by which the base of the atmosphere is directly heated. Without it, the near-surface air could never become nearly co-thermal with the surface, because all the noncondensing GHGs taken together lack the thermal mass to accomplish that. It is through these neglected mechanisms that a nearly null-net radiative exchange between surface and the bulk constituents of the atmosphere, including clouds, is maintained. The intensity of that exhange should not be confused with energy transfer rates, which are a separate matter.
The “ballgame” analogy nevertheless can be made semi-realistic for those who lack deeper physical comprehension. Think of a pitching machine that flings balls at a backstop that forcefully bounces them back to a bevy of inept fielders with a collective .500 fielding average. They are weak-armed to boot and can only roll balls back toward the backstop. There stands the noted hitter, “Mighty” Joe Aqua, who picks up the returned balls at the backstop and hits them into the outfield, well beyond the infielders’ reach. The outfielders delight in throwing the balls into the bleachers and beyond. There is no infinite loop of returned balls that would double (as in the binomial series) the number of balls reaching the backstop. There’s only the increase indicative of the fielding average.
Oliver Ramsay, your explanation needs a few clarifications…
“A colder thing radiates energy, not heat, to a hotter thing with nary a care. The hotter thing absorbs what it is sent, but it doesn’t become heat because it doesn’t result in the average frenetic motion of all those particles becoming more frenetic.”
Radiation will register as a temperature increase if the radiation is within the absorption spectrum of the other body (colder or hotter, doesn’t make a difference). That’s how a microwave heats food, and how the sun heats the earth. The radiation results in more frenetic motion of the bonds within individual molecules (stretching, rocking, scissoring). Unless the molecule exists in a vacuum, that bond motion will result in the molecule pushing against neighboring molecules. The molecules then move in relation to each other – a temperature increase.
“The temperature is the average speed of all the particles.”
Almost, but not quite. Temp is the average kinetic energy – that’s velocity times mass. Given clusters of 100 atoms each of iron and hydrogen, the temperature of the iron cluster will be much higher than the hydrogen cluster if all atoms have the same average velocity. It takes more energy to move a higher mass to a given speed. Think of how much you would have to speed up iron atoms to get them moving as fast as hydrogen atoms are at room temperature – you’d have to vaporize the iron.
@davidmhoffer says: February 22, 2011 at 11:36 am
In an idle moment I foolishly returned to this thread. Ira Glickstein PhD’s protegé wants the last word, apparently.
‘What did the early settlers use to insulate their houses in the depths of winter? Answer: SNOW!’
So all the photons streaming into the house from the cold snow kept the house warm? Mmm. Food for thought, there, davidmhoffer.
– The early settlers didn’t know what Professsor Planck knew about the relationship of the energy levels of photons and the temperature of the body emitting them. Ira Glickstein PhD doesn’t seem to know this either – at least it plays no role in his rubber ball and kitchen scale model, which you so admire.
– Snow is cold, though. It is not capable of raising the temperature of any object above its own temperature. If you don’t generate heat in your snow covered house it will quite quickly get to snow temperature. Use snow as an insulator, or to keep the wind from whistling between the logs, but forget the energy it is radiating. It’s only useful if you are colder than snow.
‘The physical model isn’t designed to explain how CO2 interacts in the atmosphere over all. The model was designed to illustrate one single characteristic of CO2, that being how it reacts with long wave radiation in the context of the “greenhouse effect”. It does a pretty good job of that.’
No it doesn’t. Ira Glickstein PhD’s model IS bonkers, and I don’t understand a word of this defence of it. You cannot use the laws of motion as an analogy for the laws of thermodynamics. You cannot use a scale measuring – er… what? momentum? work? general bounciness? – for temperature. You cannot just sum impacts together as an analogy for increasing temperature, or heat, or… whatever.
I note with a sinking heart that he is planning a sequel. More overcooked graphics and ridiculous analogies, I bet.
Nobody argues against the fact that some trivial increase of atmospheric CO2 has been, indeed, taking place during the last few decades. It is very minor, compared even to the most recent historically recorded swings of the same parameter.
The most important point is that this CO2 increase is not correlated with the temperature changes in any way; that is, there is no “greenhouse effect.” None. Nothing to worry about, nothing to discuss.
It is also important to remember that this increase is negligible, compared to drastic changes of CO2 concentration in the atmosphere, as measured during the 19th and 20th centuries. The proponents of the AGW hypothesis, including the authors of all IPCC papers, are inexplicably (or understandably, depending on your point of view) ignoring this fact.
On the long-term, geological scale, the amount of CO2 in Earth’s atmosphere was almost always much higher than today.
The veracity of Mauna Loa record is a secondary issue of little importance. Willis Eschenbach, whose opinion I respect, even published an article on WUWT, few months ago, defending the Mauna Loa record.
However, I remain a skeptic. The Keeling’s curve is simply too smooth, too artificial, compared to most other CO2 data, to be real. Something is wrong there, something is being done with the equipment, or with the calibration methods, or simply with the representation of acquired data, to produce the desired curve. I am not a specialist in calibration of Siemens gas analyzers but some specialists, including Knorr, made the same observation.
Finally, when I am told that Mauna Loa record is confirmed by the measurements made on several other stations around the globe, I cannot help but keep in mind that all these stations are staffed by people carefully chosen to walk the green party line, and all these data are prepared and published, almost exclusively, by the green hoax zealots.
There is no hope for any objectivity in this field. Too much money, too many careers, too huge a corruption of people and information are involved for me to trust anything or anybody. I only trust (to some extent) my own eyes and brain, comparing what other people are saying, trying to separate the husk from the grain, and to adjust opinions by taking into account the self-interest of opinion-makers.
I am sure that time will prove me right, as it has on many other occasions. Meanwhile, as CO2 concentration gets a bit higher every month, global temperatures are dropping precipitously. This warms my heart but costs more and more in heating expenses.
Steve says:
February 22, 2011 at 12:41 pm
Oliver Ramsay, your explanation needs a few clarifications…
————————————
Thanks Steve,
I certainly take your point “velocity X mass”.
My contention was that there would not be thermalization arising from vibrational excitement if the incoming radiation were less than the outgoing, as would be the case where the other body is cooler.
Now, I know nothing about magnetrons, but I assume that the filament is at a higher temperature than the food it heats. The sun is hotter than planet Earth, albeit somewhat cooler than planet Gore.
davidmhoffer says:
February 22, 2011 at 11:36 am
… “The point being that the temperature of the surroundings has NOTHING to do with the calculation. Any body emmits heat or energy flux as photons, and those photons travel at the speed of light until they hit something.” …
————–
Hi David,
Well, humm. I’m going to have a hard time explaining this to you so bear with me, I have thought much on why these people could possibly think the way they do and the only thing I keep coming up with has to do with what Feynman showed so very clearly with little simple cartoon drawings like Ira has drawn above. See this link:
http://vega.org.uk/video/subseries/8
You only have to absorb the first and a bit into the second lecture to see what I am about to say.
It gets into the statistical amplitude at any given point in space being the possibility of a photon being found at a that point. He gives a number of examples, reflection and gratings, explaining to the audience just how photons can possibly cancel to where there is no photons at all at some places and the amplitude is zero so the probability is zero. His imaginary scintillators are recording absolutely no photons where clearly there should be photons found there for the whole surface is being illuminated. I sure hope you don’t think IR is somehow different that SW in its purest sense.
Kind of like taking a large hollow perfect sphere, perfectly smooth and it the same temperature everywhere, what is the amplitude calculated by his quantum electrodynamics at any point within. I really don’t know, no, I think zero. Clearly there would be at any given point inside the sphere all frequencies, all polarizations and all directions. Do all amplitudes cancel like in the problem he was having with the infinities?
If you look at this one way then yes, there would be no photons within the sphere at all, all canceling as in reflection where there is absolutely no photons. If you believe there is no way photons can cancel, that is, there is no place in that sphere where the amplitude is zero then you are visualizing as you stated above that in your words “the temperature of the surroundings has NOTHING to do with the calculation”
I tend to lean on Feynman’s side. There is cancellation but I don’t have the facilities, programs and books with the equations to prove it to you. So, I see why there is two sides to that argument.
Now if you ever tries to measure within that sphere you could not for any equipment or probe would destroy the symmetry and cast an infinite number of shadows on the opposite side. Then I think you would see you imagine, photons everywhere within!
Whoops… number of misspells above so please ignore.
to Alexander Feht
I’ve been studying Keeling in detail. And I am rapidly coming to the conclusion that Keeling knew for quite a while that CO2 was not causing temperature rises, and could not cause temperature rises. He had to be aware of the data from Amundsen-Scott that showed no rise in temperature while an increase in CO2 was recorded. The Antarctic is the most pristine site in the world to take baseline data. And he knew it….I found evidence that he knew of its pristine nature. The south pole is much better than Mauna Loa. But, when funding wound down, he probably chose Mauna Loa to focus on because its a much nicer place for him to live and hang around rather than the South Pole.
From: http://www.aip.org/history/climate/Kfunds.htm
“The survey’s logistics, like its instruments, depended on things that happened to be available for unrelated purposes. One lynchpin would be a weather observatory built in 1956 atop the volcanic peak Mauna Loa in Hawaii. Rising above the lower atmosphere and surrounded by thousands of miles of clean ocean, it was one of the best sites on Earth to measure undisturbed air. Funding for the Mauna Loa Observatory was split between the U.S. Weather Bureau and the National Bureau of Standards. It was also reported that “The Armed Forces are keenly interested in some of the projects at Mauna Loa” thanks to concerns with high-altitude equipment and monitoring satellites.(9) The military accordingly provided help for road-building and the like.
Another key station would be in the pristine Antarctic, where scientific work depended wholly on military assistance. It was almost a parable, the coldest of Cold War science. The U.S. Navy and other services, intent on developing expertise that would prepare them for warfare under any circumstances, would gladly pick up some credit along the way by giving scientists heroic logistical support. This was only one of many ways that the Navy and other armed services, by funding work connected with their military missions, provided essential support for research that would turn out to tell something about climate change. ”
“When Keeling set up his recording spectrophotometers at these stations, they proved to be worth their cost. Spikes in the record on the strip charts pointed to CO2 contamination blowing past from volcanic vents on Mauna Loa, and from machinery in Antarctica. Stalking such problems with a meticulous attention to detail that verged on the obsessive, Keeling managed to extract a remarkably accurate and consistent baseline number for the level of CO2 in the atmosphere. In late 1958, his first full year of Antarctic data hinted that a rise had actually been detected.”
That website
http://www.aip.org/history/climate/index.htm
although run by someone who does believe in AGW, is very rich in historical detail of how this whole fiasco came about.
David, one more thing. If you go ahead and watch lecture three and four, it gets into the couplings in his diagrams. That is another reason I think no photons within the sphere. For at every interaction there is a coupling cost (loss of energy) that occurs and it seems on the top that if you were always having photons passing back and forth in reality then there would be a constant coupling loss of energy occurring and that does not seem real to me. In a nutshell *that* is why I think no photons within. Of course the coupling is the fine structure constant.
Oliver Ramsay “Thanks Steve, I certainly take your point “velocity X mass”. My contention was that there would not be thermalization arising from vibrational excitement if the incoming radiation were less than the outgoing, as would be the case where the other body is cooler.”
Well there would be thermalization (that has a specific definition in thermodynamics, btw), but I get your meaning. As you pointed out, radiation from a cooler object will slow the rate of cooling of the hot object, not increase the temperature of the hot object above it’s initial temperature.
A ball of steel that is half a degree away from molten in a 30 degree room won’t get to it’s melting point if you move it into a 300 degree room. The room is still the cooler object, so the steel ball cools. The only difference is that it will cool slower as it is cools to a “room temperature” of 300 degrees instead of 30 degrees. The room does transfer energy to the ball, but nothing in comparison to the original energy content of the ball.
Eureka!! – The proof of “back radiation” as a heat-engine, is that The Sun has lasted for some 4.5 to 5 billion years – It is obvious, even to a dumb-scull like me that back radiation from the planets, moons and other bodies floating around in the solar system is keeping The Sun much warmer than it otherwise would be. –
Oh no, no, no I thought for a moment I had it there but then I suddenly remembered the “Ice-core graphs” and they show that, in the past when both CO2 concentration and Earth’s temperature are at max. peak (and back radiation both from CO2 and Water Vapour may also therefore very well be at maximum) the Earth usually chooses to return to glaciations.
Oh well, I had better a look for “The Hot Spot”- I suppose.
Fred Souter: Say you have a regular camera that takes photos in the visible light range (shortwave radiation). You take a photo of the Sun with that camera, and that is proof that shortwave radiation from the Sun arrived on Earth. No controversy here. Right?
OK, now you get a camera that takes photos ONLY in far infrared light (longwave radiation). It has absolutely no sensitivity to light in the visible range. I worked on aircraft systems that had what is called a Forward Looking IR (FLIR) camera. You may have seen video from such a camera showing how, in absolute darkness, the people in the airplane can see things of higher and lower temperatures. For example, if you are looking at a moving truck at night, the engine compartment and the tailpipe and the tires will look white in the image and the rest of the truck will look gray or black. If it is daytime, with a camera of that type, you can distinguish between a truck that has its engine running now or recently had it running and a similar truck that has been parked for a while and has cooled down.
If you are in space, far from Earth, and you point that FLIR camera at the Earth, in daytime or nightime it will show the warmer parts of the Earth in white or light gray and the cooler parts in dark gray. It will show space around the Earth in black because there is no longwave radiation coming from empty space. OK so far?
Now, take that FLIR camera near the Sun and point it at the Earth. Will you be able to distinguish the Earth from the space around it? YES. The Earth will be a lighter shade, in contrast to the space around and behind it. That is proof that the longwave radiation from the Earth has reached to the Sun and some of it will impact into the Sun and, ever so slightly, warm it.
That shows that the Earth, which is a lot cooler than the Sun, emits longwave radiation into space, some of which falls onto the much hotter Sun, warming it a tiny bit, even as the Sun emits shortwave radiation into space, some of which falls onto the cooler Earth, warming it considerably.
If that example is not convincing, imagine (as an earlier commenter did) that you and I are in a water fight and you are spraying me with water from a fire hose. I am spraying you with water from a garden hose that happens to have blue dye in it. No doubt, I will get a lot wetter than you, but … BUT, you will get some of my blue water on you, will you not?
When scientists say that radiation goes from the hotter to the cooler object, they are talking about the NET transfer of heat energy. The Sun transfers a lot more energy to the Earth than the Earth does to the Sun, so the NET transfer is from Sun to Earth. However, just as some the blue water from my small hose hits you, and much more water from your fire hose hits me, the NET transfer of water is from you to me – but you get some of my blue water. Right?
During the morning rush hour, 100,000 cars come into the city and 10,000 go out of it. The NET flow is 90,000 cars into the city. However, as anyone who cares to look will see, there is a flow in both directions, both into and out of the city.
“No, your coat will NOT radiate heat back to your body. It only radiates to objects cooler than itself. Again, this is a basic concept of Thermodynamics. So far, we have found no examples in the universe to refute this law.”
Your wording is a bastardization of the second law. Radiation and heat are different types of energy transfers, for one, so “radiate heat” is just a muddy term.
Unless your coat is at absolute zero it is radiating energy to everything around it. Odds would be extremely high that it absorbs more heat from the environment than it emits, though.
“Steve says:
February 22, 2011 at 12:41 pm
“The temperature is the average speed of all the particles.”
Almost, but not quite. Temp is the average kinetic energy – that’s velocity times mass.”
Almost, but not quite. 🙂 Velocity times mass is momentum. Kinetic energy is 1/2mv2.
THANKS “PJP” – your mention of truckloads of energy in the Willis Eschenbach Topic is what triggered this Topic. Good to “see” you again!
Really? Someone said “It is better to light one little candle rather than curse the darkness.” If I light a candle and take it near the Sun, will the Sun not get even a teeny, tiny bit warmer?
I remember my high-school physics teacher’s interpretation of the first law of thermodynamicss.
He would say “joules equals joules equals joules” while jumping up and down, nearly frothing at the mouth.
Many here are saying that there is a difference between energy and heat, but my physics teacher would disagree.
Another thing is the following which is a quote but I cannot remember the source, but I will follow with an informal proof of the concept. Here goes, difficulty factor pi.
“If all the matter in the universe consisted of stoves and pots of water, then in between a google and a googleplex years, one of the pots would freeze.”
If anyone recognizes that and can lead me to the source, I would be appreciative.
Now for an informal proof
Imagine a volume of gas at a certain temperature, temperature being the average kinetic energy of the molecules of the gas, which exist with differing velocities according to the Maxwell-Boltzmann distribution. Now if we let time advance and collisions between the gas molecules to occur, it would be reasonable to believe that when two molecules collide with initial velocities a and b, one faster than the other such that a > b, then after collision, the velocities would be a1 which would be lower than a and b2 which would be higher than b2. Then continuing, after a finite amount of time the velocities of all the molecules would be the same.
But, since this does not happen, because gases maintain the maxwell-boltzmann distribution, thus it is unreasonable to conclude that two molecules that collide always transfer energy from the faster molecule to the slower, sometimes a slower molecule increases the energy of a faster molecule.
And where am I going with all this….
The fact that heat is always transferred from hot to cold is not a fact at all, it is just due in part to chance, it is just more likely.
As for disproving the greenhouse effect, I prefer the essay “Ponder the Maunder”
It varies from instant to instant; if the sun sets (e.g.) while you are outside, you will begin to chill somewhat as the coat’s emissions now exceed absorptions. Then a new balance will be reached, varying around a new lower “set point”. (Variations in breezes, body heat emitted due to exertions, etc.)
Ira Glickstein, PhD says:
February 22, 2011 at 6:38 pm
“During the morning rush hour, 100,000 cars come into the city and 10,000 go out of it. The NET flow is 90,000 cars into the city. However, as anyone who cares to look will see, there is a flow in both directions, both into and out of the city.”
———————————-
You didn’t quite appreciate what my metaphor was about. It was not trying to represent radiation of energy. You can step on the gas and the brake at the same time but you can’t speed up and slow down at the same time.
I was just saying that although something can be sweet and sour at the same time, it can’t be hotter and colder at the same time. If a hotter object is heating a cooler object a lot and the cooler object is heating the hotter object a little at the same time that the cooler object is cooling the hotter object a lot and the hotter object is cooling the cooler object a little, we have landed on planet Gore and we probably will burn up.
In reply to Dan’s post (circa February 22, 2011 at 12:04 am);
The zero degree was a hypothetical “temperature” that was chosen to align with the original authors “scale” where zero was the initial condition, i.e. the average temperature of the Earth’s surface (~255K). It is not meant in any way to represent zero degrees Kelvin.
I am still waiting for info about how the laws of thermodynamics do not apply to electromagnetic radiation.
Cheers, Kevin.
“”””” bob says:
February 22, 2011 at 6:54 pm
I remember my high-school physics teacher’s interpretation of the first law of thermodynamicss.
He would say “joules equals joules equals joules” while jumping up and down, nearly frothing at the mouth.
Many here are saying that there is a difference between energy and heat, but my physics teacher would disagree. “””””
I can’t even imagine just where you found that; because I don’t recall anybody asserting that. “Heat” is certainly a form of energy; and I don’t think anyone here has denied that. In particular it is the kinetic energy of molecules that are at a Temperature above absolute zero, and in fact the Temperature is defined in terms of that energy; specifically the mean energy per degree of freedom.
So you simply have been misreading what people have been writing. Now there have been several including me; who have said that Heat (energy) and electromagnetic radiation energy are NOT the same; so what did your Physics teacher tell you about that ?
So what is YOUR interpretation of the First Law of Thermodynamics; now that your teacher, apparently has taught that to you ?
As for your “proof” bob, that heat only sometimes by chance, moves from high Temperature to low Temperature; there’s a snag in your argument; because that Temperature is defined in terms of the mean energy per degree of freedom of a large assemblage of molecules; not of a single molecule. It is true, as I have also argued, that the statistical distribution (Maxwell-Boltzmann) of kinetic energies of a large assemblage of molecules (at a given Temperature), is identical to the time distribution of the energy of any single molecule; averaged over a suitably large time interval.
Since the M-B distribution is a map of where (energy wise) any molecule of the set can be found at any instant, and over time any particular molecule could be found at any location in that distribution; therefore one can argue that the Temperature is also the time averaged energy of any single molecule in the set.
But your snag is still there, because the time averaged energy distribution of any single molecule loses any information about any single inter molecular collision such as the collision you described.
So your proof, is no proof of anything; other than that you do not understand the problem.
“”””” Kevin (not a PHD) says:
February 22, 2011 at 7:22 pm
In reply to Dan’s post (circa February 22, 2011 at 12:04 am);
The zero degree was a hypothetical “temperature” that was chosen to align with the original authors “scale” where zero was the initial condition, i.e. the average temperature of the Earth’s surface (~255K). It is not meant in any way to represent zero degrees Kelvin.
I am still waiting for info about how the laws of thermodynamics do not apply to electromagnetic radiation.
Cheers, Kevin.
Well Kevin (not a PhD); you do not need a PhD to know that the statement of yours above is nonsense. There is nothing at all hypothetical about absolute zero; and there are no degrees Kelvin; just simply Kelvins; and zero Kelvins IS the absolute zero of Temperature and in no way hypothetical.
Perhaps you could describe for us, some of your own investigations at Temperatures lower than your hypothetical and quite arbitrary zero Kelvins; and it is not and never has been related in any way to the average Temperature of the Earth surface; or of any other planet.
So specifically which Law of Thermodynamics is Electromagnetic Radiation related to.
Shall we start with the zeroth law first:- “All systems which are in thermal equilibrium with a given third system, are also in mutual thermal equilibrium.”
So when was the last time you encountered an electromagnetic field that was in any kind of equilibrium; and specifically thermal equilibrium; which would require it to have a specific Temperature. No I don’t think the zeroth law is any help.
Maybe the First Law of Thermodynamics:- “The total internal energy of a system is a conserved quantity. Energy cannot be created or destroyed, but only transferred from one system to another.” My that is not quite the same as your Physics teacher’s mouth frothing version. Well Photons can certainly be created and destroyed, as can Electromagnetic waves as described my Maxwell’s equations. Dosen’t look like the first law applies to electromagnetic radiation either.
Well I’ll let you take a look at the others yourself to see what you can come up with; maybe you could review it with your frothing Physics teacher.
Here (IMHO) is the “money quote” from PJP;
“But this is NOT new energy. It is energy that has already been accounted for and should NOT be re-counted.”
With respect to the original author I would like to edit this quote “But this is NOT new energy. It is energy that has already been accounted for and ACCORDING TO THE LAWS OF THERMODYNAMICS CANNOT, REPEAT CANNOT be re-counted.”
In my opinion this is EXACTLY the flaw in the “greenhouse theory” you cannot count the energy twice any more than you can count your paycheck twice (at least legally that is).
Cheers, Kevin.
To Mr. George E. Smith;
Quoting your comment directly;
“Dosen’t (sic Doesn’t) look like the first law applies to electromagnetic radiation either.”
Again I respectfully suggest you provide references.
All of my training teaches me that the First Law of Thermodynamics (and all of the other laws as well) apply to all forms of electromagnetic radiation. Sorry, I realize now that this might shatter your belief in the “greenhouse effect”, but these are the facts. I did not invent them, I’m just relaying them to you and others that may or may not be receptive to them.
Again the “scale = 0” analogy was based on the original authors choice of “scale weight reading (analogous to the surface temperature)”, this is the original text, hopefully quoted accurately. This does not (as far as I can interpret the original author’s intent in any way represent the “hypothetical” 0 degree Kelvin case). As an aside 0, (zero) degrees Kelvin is still (as far as I know) a hypothetical situation that nobody (including myself) has ever achieved.
Cheers, Kevin.
@Ira – re candles and the sun: I can’t be absolutely, 100% certain, I am not a physicist, but do try to understand some of the basics, even if that may be without a complete grasp of the fundamentals – life is just too short, and I made the decision a long time ago to drop my university career as a physicist to study other topics which I found more interesting.
That said, I do have a grasp of how heat (energy) moves through exciting molecular state, and there really is a minimum amount of energy required to do this.
So, sadly, no, I do not believe that a candle held near the sun will warm it just one tiny bit.
——-
@ Kevin – I don’t argue that there is an effect which an atmosphere has which keeps the surface of a planet warmer than it would be without one. I will even go so far as to say that I further buy into the idea that different gases will have different effects, and that gases which are opaque at certain frequencies which coincide with the frequency of radiation from the planet will work better at keeping the planet warm than a gas which does not exhibit those properties.
However, I consider the term “greenhouse effect” a misnomer, and that has probably contributed to more misunderstanding and argument than any other single item.
A greenhouse’s warming effect is predominantly due to its impeding convection, not impeding specific frequencies of radiation. The Earth’s atmosphere has no such effect.
What the atmosphere is, is an insulating blanket. A special sort of insulating blanket.
It has lower insulating properties for higher frequency radiation than it does for lower frequencies. This is mostly due to H2O rather than CO2, but I won’t deny that there is some small contribution by CO2.
But back to the point you originally commented upon – yes, there is only one energy input (the sun), energy can be (and will be) shuffled around by the atmosphere, but that shuffling will never add more energy. In fact, it will absorb some, because moving around the atmosphere (and the seas) takes energy, and that comes from only one source (well … not true, there is the radioactive decay at the center of the Earth, but in comparison I think we can ignore it for this discussion).
So The atmosphere will actually remove some small fraction of the energy input, but NEVER, EVER add to it.
George E. Smith says:
“Now there have been several including me; who have said that Heat (energy) and electromagnetic radiation energy are NOT the same; so what did your Physics teacher tell you about that ?”
Let’s see, since heat capacity is commonly measured in Joules per Kelvin, thus heat can be measured in joules as in you need x amount of heat in joules to raise the temperature of y from z to d. And although electromagnetic radiation is normally specified by its wavelength or frequency, I’ll leave it to you to verify that joules works just as well.
The first law is commonly stated that “energy can neither be created nor destroyed only altered in form”
And do you believe that heat cannot be transferred from a cold object to a warmer one?
And since you brought up degrees of freedom, I’ll assume you know that a photon can have but three, 2 for the direction it is traveling and one for the joules.
And the macroscopic properties of matter must be consistent with the microscopic properties, do you agree?
Cheers
“George E. Smith says:
February 22, 2011 at 8:01 pm
Well Photons can certainly be created and destroyed, as can Electromagnetic waves as described my Maxwell’s equations. Doesn’t look like the first law applies to electromagnetic radiation either.”
If an electron goes from the third energy level of hydrogen to the second, a photon is created, but the hydrogen atom loses the same amount of energy. Conversely, if this same photon hits another electron in the second energy level of another hydrogen and knocks it to the third level, the photon is destroyed but the hydrogen atom gains the same amount of energy. Do you agree?
Kevin,
My point was that there will be more photons emitted after the first one, with a corresponding drop in temerature of the emitter. If the first photon for some reason returns to the emitter it will find the emitter several “photons” cooler than when it left.
It would then be possible for it to heat the emitter to some degree.
There will of course be no net increase in energy or temperature, only a lower rate of cooling.
We need to somehow explain why cloudy nights are warmer than clear nights and other similar phenomena.
Your comment is appreciated.
First, thank you for taking the time to answer so thoroughly. This is starting to make sense to me.
If I can rephrase what you’ve said: “heat” is the excess or additional excitation caused by radiative energy. (I’m not going to worry about conductive or any other form at the moment.)
Going by what I understand so far, it would seem that the cooler object influences the way the warmer object cools by slowing down the cooling,, but that the colder (or less energetic) the cooler body is, the less it slows down the cooling of the warmer body.
Both are radiating “back and forth,” which means that some of the energy lost by the warmer body is being replaced by the cooler body. The less energy from the cooler body, the less energy is fed back into the warmer body, and hence the less heat.
But in that case, it still seems as though “heat” is being exchanged.
Here’s what I’m seeing, and maybe you can correct my impression:
Body A is really hot. That means that it has absorbed a batch of energy causing its molecules to buzz all over the place. This movement is called “heat.” Now, Body A is also all alone. There may be another body somewhere else in the universe, but for all practical purposes, it’s just sitting there somewhere in between galazies.
Some of Body A’s energy is being radiated out in discreet quantum, and this energy never comes back. Every bit of energy simply shoots out in a straight line, never to return.
Now along comes Body B. Body B has absorbed less energy than Body A, therefore its molecules are buzzing around a lot more slowly. But they’re still buzzing. Body B takes up position close to Body A. Now some of the energy from Body A is getting absorbed and re-emitted by Body B, and some of the re-emitted energy is going back to Body A. As a result, Body A is becoming cooler at a slower rate than when it was all alone. The less heat Body B has, the faster Body A will cool, because it will be more like being alone. The more heat Body B has, the slower Body A will cool.
Does this make sense? Or am I still missing something?
Hi Ira, and thanks for trying to help clarify this for me. I’ve been somewhat enlightened by Oliver’s explanation, which is helping me understand the conceptual difference between heat and energy.
Now you are saying that “heat” is a measurement of net flow. I think this may now clarify an error I was making in my understanding of Oliver’s explanation.
To use another analogy, as long as my business is bringing in more money than it’s putting out, it is making a “profit.” The amount of this profit may increase or decrease, but as long as more money is coming in than going out, I still have a profit.
Am I close?
Living In The Lag
What Ira’s cartoon mostly lacks is the 4th Dimension: time.
In my Gedanken Experimental revisualization, we start with the Earth just a few degrees below its historic minimum; the exact number is unimportant.
*But it is shielded from the Sun totally (by, shall we postulate, an angled omni-mirror that bounces away any outgoing radiation into deep space off the ecliptic).
*Then, suddenly, the mirror is withdrawn, and a short time later the wave front(s) of radiation from the sun begin impinging on the planet.
*SW is absorbed by the surface and some is re-radiated in the CO2 signature band (~15μ), and absorbed and re-radiated, etc., eventually resulting in some form of outgoing radiation of equivalent energy. This is the LAG period, let’s call it Lp.
*From that moment on, the outgoing radiation matches incoming (averaged over a few multiples of Lp).
* But the energy level in the atmosphere and on the surface is higher by the total emitted as 15μ for one Lp’s duration. This has a slight warming effect.
It should be a fairly direct exercise to calculate, to a reasonable approximation, the temperature impact of such emission over one Lp. That is the total we’ve “borrowed” from the first moments the mirror was zipped out of the way.
* Note that if the mirror is suddenly (instantaneously, Gedanken-wise) zipped back into place there will be continued “Lagged” emission till that little reservoir is drained, and we’d experience another Lag when the mirror is re-removed.
Wayne;
Well, humm. I’m going to have a hard time explaining this to you so bear with me, I have thought much on why these people could possibly think the way they do and the only thing I keep coming up with has to do with what Feynman showed so very clearly with little simple cartoon drawings like Ira has drawn above. See this link:
http://vega.org.uk/video/subseries/8>>>
Sorry Wayne, I didn’t watch the series, and as for your explanation, sorry again, but the links I posted are to the explanations of laws of physics and the mathematical equations that quantify them that you can find in any physics text book. If your explanation is correct then you’ve debunked laws of physics that have been established since 1879 and been verified by experimentation thousands of times. You can hypothesise all you want about how photons do this that or the other, but the amount of energy radiated by a body at a given temperature is governed by those laws, proven repeatedly by experimentation, right down to the later work of Wiens and Planck and others that allow not only calculation of how much energy is radiated at a given temperature, but at what frequencies and the distribution of those. Go back and look at the formulas again – they are independant of the temperature of the surrounding environment.
RichardSmith says:
February 22, 2011 at 1:03 pm
In an idle moment I foolishly returned to this thread. Ira Glickstein PhD’s protegé wants the last word, apparently.>>>
Ira is my protege? I’m flattered. Being as he has a degree in physics, a PhD I understand where as my degree is in….oh yeah. I don’t have one.
‘What did the early settlers use to insulate their houses in the depths of winter? Answer: SNOW!’
So all the photons streaming into the house from the cold snow kept the house warm? Mmm. Food for thought, there, davidmhoffer.>>>
Sigh. No. If there is a heat source in the house, the house will be warmer with snow piled up all around it than with no snow. And, to anwer your next point, yes, if there is no heat source in the house, it will drop in temperature until it is at the same temperature as the surroundings. But it will drop much slower if the house is insulated with snow.
But let’s tackle your most seriously flawed statement:
Use snow as an insulator, or to keep the wind from whistling between the logs, but forget the energy it is radiating. It’s only useful if you are colder than snow.>>>
Someday perhaps you will come winter camping with me? We’ll trudge out into the wilderness and find camp site. You’ll lay your sleeping bag down on top of the snow and I will go to work pushing loose snow into as big a pile as a I can. You’re probably already snoring by the time i finish hollowing out my pile of snow and crawling insider of hit. Now the snow is colder than I am, yet an hour later I’ll probably have to take off my jacket to keep from over heating, maybe even open the sleeping bag zipper. In the morning I come to check on you, see if you’re ready to hike the next leg. Unfortunately you are frozen solid, convinced that the snow of the Quinzee would only help you if you were colder than the snow.
You might argue that my pile of snow, called a Quinzee wouldn’t have warmed up without my body heat. True. And that is the point. Your body heat does warm the snow, and the snow then transmits some of that heat back into the quinzee. Igloos work by the same principle.
The only foolish mistake you made in returning to this thread was to continue commenting.
davidmhoffer says: February 23, 2011 at 4:22 am
‘”In an idle moment I foolishly returned to this thread. Ira Glickstein PhD’s protegé wants the last word, apparently.>>>”
‘Ira is my protege? I’m flattered. Being as he has a degree in physics, a PhD I understand where as my degree is in….oh yeah. I don’t have one.’
David – we’ve abused each other enough by now to be on first name terms – your ability to misread almost everything I write astonishes me. I wrote that you were Ira Glickstein PhD’s protegé, not that Ira Glickstein PhD was your protegé. Perhaps you are being ironic in a really cool, self-deprecating way. I’d certainly lay off the Red Bull for a while.
‘Someday perhaps you will come winter camping with me?’
You old smoothie! But – and here I have to be brutally frank, I’m afraid – there’s a very long list of people (starting with Keira Knightley) that I’d rather go into the woods and melt snow with than you.
Ah! There’s the phone. Must be Keira. Have to dash. Toodlepip! Melt some snow for me!
I have two comments:
First, Ira Glickstein was describing a simple model of radiation and the greenhouse effect, just as Galileo was using a simple model of rolling balls down and up inclined
planes to reach the conclusion that bodies in motion tend to stay in motion unless acted on by a force. The attacks on Glickstein’s model were an irritant to me, like attacking Galileo’s model for ignoring friction which slows rolling balls to a stop in the real world. To understand any phenomena, we’ve got to start simple, as with Galileo’s experiment and Ira Glickstein’s example, and gradually add complicating factors as
we begin to understand the concepts.
Second- regarding Richard Smith and David M Hovver’s snow remarks. We are
confused by snow because it’s white and reflects visible light. In the infrared, snow
acts almost as a black body. That’s why snow melts much more quickly around tree trunks than farther out in the middle of a field.
I want to make another comment by approaching the problem from a reverse angle.
Remember that the sun radiates photons predominantly from 0-5 um.
Here is a paper that confirms to me that CO2 is (also) cooling the atmosphere by re-radiating sunshine:
http://www.iop.org/EJ/article/0004-637X/644/1/551/64090.web.pdf?request-id=76e1a830-4451-4c80-aa58-4728c1d646ec
they measured this radiation as it bounced back to earth from the moon. So the direction was: sun-earth-moon-earth. Follow the green line in fig. 6, bottom. Note that it already starts at 1.2 um, then one peak at 1.4 um, then various peaks at 1.6 um and 3 big peaks at 2 um. You find everything back in fig 6 top (the actual measurements).
Obviously we know that CO2 also has big absorption at between 4 and 5 um and most recently they also discovered some absorptions of CO2 in the UV range. So this is not shown in these graphs but we know about it and it would be there had they been able to measure it with their equipment.
the question: So what exactly happened here?
The sun’s photons hit on the CO2 and found a few places where “it went inside” (absorbed). But once the molecule was filled here (and in a new state), it started behaving like a mirror at that particular wavelength stretch. That is the only way to explain what is happening.
remember: this is the radiative cooling caused by CO2.
Now, CO2 also has absorption between 14 and 15 um. Remember that earth emits predominantly in the 10-20 um range. So we can imagine that when some of earth’s radiation hits on the CO2 at 14-15 um it will be send back to earth. This is what is called the “greenhouse effect”. It will cause some warming just as the deflection of some of the sun’s radiation (away from earth) by CO2 will cause some cooling.
The question is: which is bigger: the cooling or the warming? If the warming is bigger, CO2 is a GHG. But it appears that no one could answer me this question satisfactorily. So I don’t know (exactly).There are no results. It appears nobody knows how to test it.
In addition, CO2 also causes cooling by taking part in photo-synthesis. Namely, forests and greenery need energy to grow. That energy is extracted from their surroundings.
So what is the net effect of the increase in CO2 in the atmosphere? My results seem to indicate that the net effect is zero or possibly even slight cooling.
http://www.letterdash.com/HenryP/assessment-of-global-warming-and-global-warming-caused-by-greenhouse-forcings-in-pretoria-south-africa
I found similar results in La Paz, Bolivia during the dry months there. Also, Willis mentioned Northern Ireland (no change in temps there either).
And in Spain is the same.
If this be true, that would disqualify CO2 as a GHG.
Again, this whole discussion here is meaningless unless somebody proves to me (us) that the net effect of more Co2 is warming rather than cooling.
bob says:
February 22, 2011 at 9:35 pm
George E. Smith says:
“Now there have been several including me; who have said that Heat (energy) and electromagnetic radiation energy are NOT the same; so what did your Physics teacher tell you about that ?”
Let’s see, since heat capacity is commonly measured in Joules per Kelvin, thus heat can be measured in joules as in you need x amount of heat in joules to raise the temperature of y from z to d. And although electromagnetic radiation is normally specified by its wavelength or frequency, I’ll leave it to you to verify that joules works just as well.
—————————————-
bob,
I’d be interested to hear how heat achieves the construction of sugar moecules in photosynthesis.
Alan McIntire says: February 23, 2011 at 6:17 am
– Well this post started with Einstein and now Ira Glickstein PhD is up there with Galileo. There is no way – no way – that you can use kinetic processes (bouncing balls) as an analogy for thermodynamic processes such as absorption and emission of radiation. No way.
‘To understand any phenomena, we’ve got to start simple’ you write. Well, yes, start simply, by all means, but don’t start wrongly because you will never be right.
– Despite being material enough to be thrown by pitching machine, Ira Glickstein PhD’s balls don’t even obey the laws of motion, such as when they split and one goes upwards and one goes downwards. Don’t know what Sir Isaac (no PhD) would make of that.
– ‘We are confused by snow because it’s white and reflects visible light. In the infrared, snow acts almost as a black body.’
The phrase ‘black body’ describes a radiator/absorber that behaves perfectly in accordance with Planck’s equations and should not be used in other contexts. You seem to be using it here to mean that snow absorbs IR well. Not quite the same thing.
Alan McIntire says:
February 23, 2011 at 6:17 am
“Second- regarding Richard Smith and David M Hovver’s snow remarks. We are
confused by snow because it’s white and reflects visible light. In the infrared, snow
acts almost as a black body. That’s why snow melts much more quickly around tree trunks than farther out in the middle of a field.”
———————————————-
That’s a somewhat extravagant claim. There will always be a tree-well around a tree, where there is less snow to start with, because the branches divert snowfall to the drip-line and wind will scour close to the trunk and dump at a wider circumference.
Hence, the springtime sight of bare ground around trees.
Of course, the tree is an effective absorber and will create a micro-region of relative warmth, largely by conduction. Nevertheless, the lee-side snow mound often persists as the last vestige.
davidmhoffer:
David, I don’t want to leave the impression I was trying to correcting you, I wasn’t, just a little expanded thought. However, one statement was clearly stated wrong and there’s bound to be some other flaws in that whole line of thought. Well anyway, if you ever get a chance to listen to those lectures you might enjoy them. I find it next to impossible to discuss on a blog anyway, too easy to be taken wrong. Keep up the good and clear explanations as you did above.
“”””” Kevin (not a PHD) says:
February 22, 2011 at 8:51 pm
To Mr. George E. Smith;
Quoting your comment directly;
“Dosen’t (sic Doesn’t) look like the first law applies to electromagnetic radiation either.”
Again I respectfully suggest you provide references. “””””
Well Kevin, I was planning on coming back this morning, to at least provide a reference to the first two thermodynamic laws that I cited; (a) to credit the authors who wrote them in those words (I’m not a plagiarist), and also to show you where you can go and look for yourself. I learned the definitions I use almost 60 years ago so I’m sure they teach different words today.
So I cited here from “Handbook of Physics” Edited by Walter Beneson, John W. Harris, Horst Stocker, and Holger Lutz; published by AIP Press. I assume that is American Institute of Physics. It is ISBN 0-387-95269-1. I bought mine from the Stanford University Book Store; mine were all lost 50 years ago. Note that is a Handbook, and not a Text book, so it doesn’t teach Physics to people who don’t already know it.
And as for this “please provide references”, I do so, ONLY to give credit to sources I may draw from; not to assist others (you) to find it themselves. For that I suggest you refer to http://www.google.com, where you can find all the references you want; and then you can write them and ask them to provide you references for THEIR information.
When I went to school, the idea was to actually learn something; so you could do it for yourself; or even get somebody to pay you to do it for them. Nobody will give you a job based on http://www.google.com as your curriculum vitae.
@ Frank Lee Meidere
It’s good to see you’re still there.
Yes, outside of creative book-keeping with two sets of books, you can’t make a profit and a loss at the same time.
Heat is not the only possible consequence of radiation. For two things in LTE there is no heat transfer although they are merrily tossing energy back and forth with great abandon.
Also, UV polymerization of resins in dentistry. A lot of the energy of photosynthesis is not turned into heat until you put the log on the fire.
I hope you’re following George and Richard!
“”””” davidmhoffer says:
February 23, 2011 at 3:56 am
Wayne;
Well, humm. I’m going to have a hard time explaining this to you so bear with me, I have thought much on why these people could possibly think the way they do and the only thing I keep coming up with has to do with what Feynman showed so very clearly with little simple cartoon drawings like Ira has drawn above. See this link:
http://vega.org.uk/video/subseries/8>>>
Sorry Wayne, I didn’t watch the series, and as for your explanation, sorry again, but the links I posted are to the explanations of laws of physics and the mathematical equations that quantify them that you can find in any physics text book. If your explanation is correct then you’ve debunked laws of physics that have been established since 1879 and been verified by experimentation thousands of times. You can hypothesise all you want about how photons do this that or the other, but the amount of energy radiated by a body at a given temperature is governed by those laws, proven repeatedly by experimentation, right down to the later work of Wiens and Planck and others that allow not only calculation of how much energy is radiated at a given temperature, but at what frequencies and the distribution of those. Go back and look at the formulas again – they are independant of the temperature of the surrounding environment. “””””
For what little it is worth, I am in complete agreement with Davidmhoffer here, the thermal EM radiation from any body depends only on that body and its Temperature; and has nothing to do with the Temperature of its surroundings. People often make the same sort of mistake when talking about evaporation (say of water). The evaporation process, depends only on the Temperature of the water (liquid). It doesn’t depend on the Temperature of the air.
But the capacity of the air to retain that evaporated water, IS a property of the air Temperature via the Clausius-Clapeyron equation.
The Temperature of the surroundings of a radiating body will influence the amount of radiation from elsewhere that can land on that body; but it has no effect on the emissions from the body.
EM radiation, is a one way process. The EM force is one of the two forces of nature that has infinite range; the other being gravitation. You launch a stream of photons, or an electromagnetic wave, and it goes on forever, unless it encounters something else made of matter. At that point, you will typically get two new waves formed; one that propagates in the forward direction (transmitted) and one that travels in the reverse direction (reflected). Free space acts like a medium with a characteristic impedance of 377 Ohms (120.pi), and if a wave encounters some new medium, that has a different impedance, then you get partial reflections just like you do in any mismatched transmission line, that is not properly terminated.
The physical universe (including biological) can absorb EM radiation and convert it into all kinds of other energy forms, such as plants, or electricity, or other photons; or even as new matter itself (pair creation); and one of the energy forms that EM energy can be converted into is what we call heat; which is mechanical energy of moving atoms or molecules. In that form the laws of thermodynamics limit where you can go from there (the heat), but they don’t determine the behavior of EM fields; nor of gravitational fields.
“There is no way – no way – that you can use kinetic processes (bouncing balls) as an analogy for thermodynamic processes such as absorption and emission of radiation.”
Well you can obviously use bouncing balls as an analogy for the thermodynamic process of heat transfer. That’s what statistical thermodynamics does. Radiation, on the other hand – I agree that it’s a little confusing. Bu it isn’t THAT confusing. He’s just representing energy packets as bouncing balls.
Maybe if he started with exactly two wavelengths of light it and dropped the physical analogy it would be easier to understand?
Imagine a sun sized energy source that is emitting nothing but green light (pick your wavelength of green, doesn’t really matter). Except for what is blocked by objects visible under green light (clouds, soot, …) this light gets to the surface of the earth and heats it, but miraculously the heat is radiated as one and only one wavelength of infrared light. So at some point right above the top of atmosphere, we observe a given energy of green light coming in from the sun, and a given energy of reflected green plus infrared light coming out from the earth. If the two balance then equilibrium has been reached and the earth is as hot as it’s going to get. If there is an imbalance then the earth’s average temp is either rising or falling, depending on the sign of the imbalance. (And no, you can’t determine this by one atmospheric measurement. Heat is radiating in all directions, so you have to balance total input with total output).
Now if you add particles to the atmosphere that are only visible under our one wavelength of infrared light, what happens? The energy reaching the surface from the sun is unchanged – our particles don’t reflect green light. The particles will be excited by the infrared light, though. That means they will bounce around and hit neighboring particles – kinetic energy aka heat. And they’ll still radiate the energy they’ve absorbed as they cool off. So you have added particles to your atmosphere that are still radiating all of the incoming energy, just as before, but only after that energy has excited them. Even if 100% of the energy that they radiate is directly out of the atmosphere (not 50% back down) you’ll get a temperature increase in your atmosphere, because you have particles excited by radiation that were not there before. The average kinetic energy, aka temperature, of your atmosphere has increased. The energy flow through the atmosphere hasn’t changed one bit, but radiative energy has been converted to kinetic energy. Your atmosphere is now doing more work than it previously was.
Between the point in time that we add these particles and they reach their “maximum bounciness” (temperature) from the infrared radiation we will detect an imbalance in the total energy input/output. Input will be ever so slightly higher than output until our particles are as excited as they can get under that wavelength of infrared light.
So with only two wavelengths it really is that simple. There’s no violation of the laws of thermodynamics here. These aren’t the droids you’re looking for… move along.
Ira Glickstein, PhD says:
February 22, 2011 at 5:54 pm
hehe that analogy gave me a chuckle, very good.
This will read flippant but I really am not trying to be.
Here’s my problem with lab experiments being extrapolated to an incredibly complex and large system as our climate.
Your water fight analogy sounds quite reasonable, however in the REAL world, when I hit you with the gush of water from my fire hose, you’ll be knocked over on your a$$ and wouldn’t hit me with even a drop of water from your puny little garden hose.
And so with our wonderfully huge and complex climate/weather system. There are so many other large heat/energy exchanges happenning that the puny little back radiation is knocked over on it’s a$$.
The only place where radiation is formidable is very high in the atmosphere where the big boys don’t play (with their big fire hoses) and even then it’s game is to lose energy to space, i.e. it cools the earth.
George E. Smith:
February 23, 2011 at 9:27 am
Thank George, I was already perfectly aware of everything you just said. Should not have tried to take deeper. My mistake.
Here’s a most illuminating citation from that same Physics Handbook that I referenced above, in the Thermodynamics section.
“Electric energy may be converted loss free into heat by the Ohmic resistance of a conductor; but heat energy cannot be converted completely into electric energy. ”
Perhaps that is the key message of Thermodynamics. “Heat”, is the end of the line as far as energy usage is concerned. You can convert other energy forms to heat with good efficiency; but once you have the heat; you can’t go backto where you started; and the thermodynamic laws describe the limits of that process; and it is in the second law that you find that you can’t go up in tempertaure; only down; and the whole thing eventually grinds to a halt at absolute zero.
That is why I have often said that using electricity to generate heat for cooking or washing etc should be a Federal felony offence. It is wasteful. Electricity is obtained from other energy souces, at great expense, and we should only be using it for things that use electricity; like your electric toothbrush or your ipaeioud. And may I also add, it is also insane to use electricity for transportation.
I’m rather partial to Clausius’s form of statement of the second Law of Thermodynamics; well he said it in German of course; and my German is quite inadequate.
“No cyclic machine, may have no other effect, than to transport heat from a source at one Temperature to a sink at a higher Temperature. ”
Weird English to be sure; but that “other effect” which must accompany any uphill transport of heat, would be the doing of “work” on the sytem. That;s what Clausius meant by his ‘may not have no other effect’. And of course we know that refrigerators DO function; but they need a compressor to do the work necessary to drive the heat uphill from the cold box to the hot outside.
Incidently Clausius, is also known to have first derived the Optical Invariant from the second law. That invariant of all optical systems, whether imaging or not, basically affirms that the “brightness” of a source cannot be increased by optical transformations. Now brightness is the wrong word to use, because it has lay meanings which are quite difefrent from its scientific meaning so we don’t use “brightness” any more. Radiance (or Luminance photometrically) is Watts (lumens) per steradian, per square metre of a source area. It is of course what black bodies put out from an exit surface or aperture.
If an optical system could form an image that was of higher radiance than the source, you could take two black bodies, one at a Temperature T, and use the super optical system to image it at a higher radiance on the aperture of the second black body, and thereby drive the second BB to a higher Temperature; whcih the second law forbids.
But notice the second law applies to cyclic systems; which aren’t the same as one way systems; and EM radiation is one way; from source to the end of the universe (unless it hits something).
RichardSmith;
‘Someday perhaps you will come winter camping with me?’
You old smoothie! But – and here I have to be brutally frank, I’m afraid – there’s a very long list of people (starting with Keira Knightley) that I’d rather go into the woods and melt snow with than you.>>>
Ah, such an amusing, clever response. I give you two examples of real world instances where people keep warm by using snow that is much colder than they are. Examples that you can test for yourself, and which, by the way, kept thousands of people from early settlers to plains natives to the Inuit warm enough to live through the harshest winters for centuries. Your devastating scientific rebuttal? A poorly crafted personal inuendo.
I’m thinking that it is a very good thing that that all those people couldn’t read and didn’t have your education. Because if they did, they would have known that the snow was colder than they were, so no point building a quinzy or an igloo to stay warm in. I guess that’s an example of what you don’t know can’t hurt you? Or maybe its faith based physics? They just BELIEVE that they can stay warm inside of a pile of snow that is colder than they are and their faith sustains them? If they lose their faith in the middle of the night, do they suddenly freeze to death?
Your education in physics is useless to you unless you can observe the real world around you and understand how the physics you have been taught fits into the real world. Physics is just a way to describe how the real world works mathematicaly. If you apply the math and get something different than the real world observations, either your math is wrong or the real world is.
There is only one real world example of a warm body being unable to be warmed by a colder body that I can think of. It is an instantaneous condition that occurs when a class M entity incorrectly responds to a stimulation from a class F entity which can loosely be describes as “does this dress make me look fat?” Any error in response by the class M entity will trigger the class F entity to cease radiating warmth across all frequencies including communication bands. There are no known explanations in physics for the phenomenon although experimentation suggests the effect may be biological as certain flowering plant species brought into proximity with the class F entity seem to mitigate the condition.
Steve says: February 23, 2011 at 9:30 am
‘Maybe if he … dropped the physical analogy it would be easier to understand?’
My point exactly, Steve. Glad you agree: Ira Glickstein PhD’s analogy is a crock.
‘…this light gets to the surface of the earth and heats it, but miraculously the heat is radiated as one and only one wavelength of infrared light.’
What? The wavelength of the photons emitted by the surface is a function of its temperature, not the wavelength of the incident light. Is that what you meant with ‘miraculously’? I don’t understand why having only one wavelength of insolation simplifies things.
‘There’s no violation of the laws of thermodynamics here.’ Where did I write that the laws of thermodynamics were being violated? I wrote that ‘Ira Glickstein PhD’s balls don’t even obey the laws of motion’.
As I noted in my first comment in this post, the greenhouse effect is a perfectly clear phenomenon for which there is plenty of evidence (which you shouldn’t interpret to mean that I accept all the evils that the AGW fanatics ascribe to CO2 – I don’t). I haven’t a clue why you have served me up this garbled explanation – ‘kinetic energy aka heat’, ‘average kinetic energy, aka temperature’, ‘ The energy flow through the atmosphere hasn’t changed one bit, but radiative energy has been converted to kinetic energy. Your atmosphere is now doing more work than it previously was.’
Your final ‘move along’ I just illustrates your arrogance. Learn some physics – and learn it well – before you start lecturing others. You should also learn to read and comprehend what people write instead of just listening to the voices in your head.
Yep, still here. And George’s remarks about the sun sending energy, but not heat, to Earth also helped. I feel like I’ve got the idea if I stand very still and don’t turn my head at all to either side. But then my eyes move and I suddenly think I can see heat transfer from cooler to warmer — just not in quite the same way I was thinking of it before.
Let me stick with the “profit” analogy for a minute. While finances of any kind usually throw me for a loop, I can at least see that “money,” like energy, can be moved about, but does not become “profit,” or heat, except in some situations.
So we have bank accounts A, B, and C.
Bank account A (BA-A) has $1,000 to start. Bank account B (BA-B) has $500. Bank account C (BA-C) has $100.
Now in normal banking, funds are withdrawn and transferred according to conscious intent, but in this case the computers have gone haywire. Once every minute, the computers transfer 1/100 of the money in each account to another account. It does this in increments of $1. Furthermore, the computers believe there are ten accounts, which mean most of the time they’re transferring money to nothing, and it’s lost.
This represents objects randomly radiating energy in discrete units, only some of which are picked up by nearby objects. It also reflects the fact that objects with more energy radiate more energy.
In the first minute, the computer makes ten transfers from BA-A (1/100th of $1,000), each equalling $1. Two dollars end up in BA-B, one dollar ends up in BA-C. The rest are lost. So:
BA-A = 1,000 – 10 = 990 // Net effect is “cooler.”
BA-B = 500 + 2 = 502 // Net effect is “warmer.”
BA-C = 100 + 1 = 1001 // Net effect is “warmer.”
But in that same minute, the computer makes five transfers from BA-B, which started with $500. One dollar ends up in BA-C. The rest is lost.
BA-A = (1,000 – 10) + 0 = 990 // Net effect is “cooler.”
BA-B = (500 + 2) – 5 = 497 // Net effect is “cooler.”
BA-C = (100 + 1) + 1 = 102 // Net effect is “warmer.”
And in that same minute, the computer makes one transfer of one dollar from BA-C which is simply lost.
BA-A = [(1,000 – 10) + 0] + 0 = 990 // Net effect is “cooler.”
BA-B = [(500 + 2) – 5] = 497 // Net effect is “cooler.”
Ba-C = [(100 + 1) + 1] = 101 // Net effect is “warmer.”
As time goes on, it seems obvious that a few things will happen. First, BA-A will lose money more quickly than the rest. This is equivalent to the idea that the hotter an object is, the more quickly it will lose its heat (and the source of that whole “when-should-you-put-cream-in-coffee-too-keep-it-warm-longer” thing).
It also seems obvious that each bank account will, at various points of time during the process, both gain and lose money, meaning that while they are all losing money (going into bankruptcy), there are steps along the way in which each will temporarily gain a short term profit. In other words, while they are all cooling off, each one is also periodically getting some “heat” from the others. Most of this profit/heat will come from BA-A, which has the most money/energy to give off.
Eventually, of course, all the accounts will reach a state of equilibrium. I think there’s a problem in my analogy with the amount. Because I’ve set the computer to send out 1/100 every minute, while setting the least increment to be $1, I think we might end up with BA-A coming to a standstill with more money than the rest, whereas in real life objects would come to equal each other in the amount of heat (even if each contains more or less energy), but I don’t feel like working it out and this is a damned analogy for crying out loud and my head hurts.
So I’m left with these questions:
1. Was “heat” transferred from a cooler object to a warmer object or not?
2. If this analogy doesn’t fit, what areas are wrong?
3. Can any of this be transformed into an equation that would tell us where Jimmy Hoffa’s body is?
Thanks for putting up with me.
No, I’m wrong. Although BA-A may end up with more money than the rest when they all reach the end of their transfers, this is simply reflecting the fact that objects can have different energy levels while still having the same amount of heat. In this case, all bank accounts will come to equilibrium when they are no longer “radiating” dollars — hence the heat/profit will be the same.
RichardSmith;
You should also learn to read and comprehend what people write instead of just listening to the voices in your head.>>>
Physician, heal thyself.
RichardSmith: “What? The wavelength of the photons emitted by the surface is a function of its temperature, not the wavelength of the incident light. Is that what you meant with ‘miraculously’? I don’t understand why having only one wavelength of insolation simplifies things.”
It’s pretty obvious that in the real world the surface of the earth does not have a uniform temperature. Even if the surface were one uniform material, it’s a rotating sphere – hence “miraculously”. I only want to deal with two possible wavelengths of light, and you can’t understand how that’s simpler than reality? To question my motives for such an obvious fact makes you sound intentionally obtuse.
“Where did I write that the laws of thermodynamics were being violated?… etc… etc… blah blah blah…You should also learn to read and comprehend what people write instead of just listening to the voices in your head.”
I was actually addressing the comments in total, Mr. Kettle. The only comment of yours that I was addressing is the notion that Newton’s laws of motion can’t be used in an analogy to explain heat transfer.
In cased you haven’t noticed, WUWT commenters have been debating whether or not a “greenhouse effect” is physically possible for too long, and it’s embarrassing. An appeal was even made directly to you in these comments, to which you replied, “I’m not going to do this, nor am I going to write an alternative description of the ‘greenhouse effect’ in a comment that will disappear out of view about ten minutes after posting.”
So you flay Ira’s explanation, despite that commenters affirmed that it helps them understand, and then you refuse to provide a more helpful explanation. That is called “being a part of the problem.”
“”””” Frank Lee Meidere says:
February 23, 2011 at 1:02 pm
Oliver Ramsay says:
February 23, 2011 at 9:12 am
Yep, still here. And George’s remarks about the sun sending energy, but not heat, to Earth also helped. I feel like I’ve got the idea if I stand very still and don’t turn my head at all to either side. But then my eyes move and I suddenly think I can see heat transfer from cooler to warmer — just not in quite the same way I was thinking of it before. “””””
Hey Frank, if just ONE person can gain some insight that he didn’t previously have, from my chicken scratchings, then I will consider my time to have been well spent.
As I have said on may occasions:- Ignorance, is NOT a disease; we are ALL born with it. But stupidity has to be taught, and unfortunately there are far too many who are willing and able to teach stupidity.
I’m not here to debate with PhD physcists (I’m not one); I’d love to learn from them whatever they would like to teach; that’s one reason I’m here, but I’m also here to try and help others whose education paths took a different course. Hey I hire a mechanic to fix my cars; I can fix most stuff myself; but not as efficiently as he can; so I gladly pay him for his inestimable skills.
It’s not about what you know, but what you make out of what you know; whatever it is that you know and do.
Ira, I have read through the answers you have made to some of the comments above. All of them very good and important
But, the one which to my way of thinking is the most important of all your answers is; (Ira Glickstein, PhD says on “February 22, 2011 at 6:53 pm in an answer to what PJP says on February 22, 2011 at 9:30 am: “THANKS “PJP – ——- Good to “see” you again! ———- Really? Someone said “It is better to light one little candle rather than curse the darkness.””
And then comes the important bit -: “If I light a candle and take it near the Sun, will the Sun not get even a teeny, tiny bit warmer?”
Of course if you light a candle and take it near the Sun, the Sun will then get a teeny, or even a tiny bit warmer. This is because the candle + flame brings “new or added energy“ to the Sun. If however you was to take your best saw up to the Sun and cut a big lump out of it (energy and all) and then put it back a couple of days later, I doubt very much if you would have made the Sun any warmer than it was before. -Please think about that one -.
Ok, so “sawing a bit off the Sun including it’s energy” may sound ridicules, but that is quite a good analogy of what radiation does; it constantly takes a proportion of enrgy away from a heat-source and “throws it away”. The Sun’s radiation transports, or emits, short-wave electro-magnetic radiation away and thus avoids “a big bang” – (There may also be back radiation from planets etc. provided the radiative forces are strong enough to reach the Sun)
On a smaller scale the same “Energy Transport System” or radiative principles work here on Earth too. But here the back radiation is caused by GHGs and not “space debris”. The principle however is the same. In other words; “you cannot increase either the power or the effect of solar irradiation by the introduction of any kind of back radiation.
However -here follows a few sentences by which I stand to earn an extra PhD or even a Doctorate in Climatology from the IPCC – please read on; – “A study shows that by burning fossil fuels we are in fact re-introducing heat-energy into the Earth’s atmospheric system. This is heat-energy which should have been returned back to space eons ago but never did so until humns interferred. The study further finds that this kind of radiation is eternally damned to remain in the atmosphere and therefore cannot be re-radiated back to space as confirmed by well established energy flow budget plans. (see Trenberth & al 1997).
One of my favorite jokes is about the physics major and engineering major who are waiting for a bus outside a building. While they wait, four people enter the building and six come out.
“Hey,” asks the physicist, “Do you know how many people are in the building?”
“No,” answers the engineer, “I have no way of knowing how many people are in the building right now, but I can tell you there were at least two in the building before we came here and started observing.”
“Dumb engineer,” snorted the physicist, “Four went in and six came out, so there are exactly minus two people in there! Want to check my math?”
PS: I am an engineer, but my PhD advisor and some of my best friends happen to have been physicists, and I have the highest respect for them. My little joke was simply to illustrate how some people can ignore their experience in the real world and believe that physics theories and mathematical equations govern everything. It takes a physicist to believe quantum wierdness and spooky action at a distance and Schrodinger’s cat and other things that I have difficulty believing without some kind of physical analogy. However, I know that my knowledge base is far from complete, as is the knowledge base of all humanity, so, some of the stuff I cannot fathom may turn out to be actual truth. Einstein’s prediction of how the EPR paradox would come out if actually tested turned out to be wrong when, well after his death, it was finally checked in the mid-1980’s.
In Reply to Dan (circa: February 22, 2011 at 10:53 pm)
I agree with your statements. I try to isolate what happens to a single photon (or small packet of energy) to make it more clear how the “Greenhouse Effect” cannot create any “Extra Energy”. If it cannot cause this at a microscopic scale, the fact that there are billions and billions of photons (apologies to Carl Sagan) makes no difference. And the fact that it “all happens very fast” also makes no difference.
Quoting yourself;
”We need to somehow explain why cloudy nights are warmer than clear nights and other similar phenomena.”
It is already explained, the clouds do indeed slow some forms of EM radiation. This change in the “speed of heat” varies with the amount of cloudiness. EM radiation is absorbed and remitted backwards towards the surface and it has to try again to escape. Slower cooling == Temporary Higher temperatures. The operative word here is temporary. In the case of clouds this happens across a broad wavelength range. Also the clouds have a larger thermal capacity and require more energy from the surface to raise their temperature which also slows the heat flow away from the Earth.
Unfortunately the “Greenhouse Effect” is credited with slowing this heat on a “permanent” basis with a resulting “Higher Equilibrium Temperature”. This is explained in some references as a “Net Energy Gain”, or in the press as “Heat is Trapped”. Neither of these is possible.
Ironically enough (IMHO), the actual effect of increases in (non-water vapor) GHG’s (especially CO2) is that energy actually travels through the atmosphere faster since it is travelling at the speed of light (quite speedy) versus the speed of heat (comparatively sluggish) through the non-GHG’s via conduction and convection. Yes the non-GHG’s may not emit IR radiation to cool the Earth, but the energy that travels through them can (and does) return to the surface and is can then be emitted through “windows” in the atmosphere. This slows the energy much more than a few more bounces as EM radition.
So increases in manmade GHG’s (again IMHO) causes the gases in the atmosphere to warm up faster after sunrise and to cool faster after sunset. In my humble opinion this effect is so small that we could not possibly spend enough money to observe, measure and model it. The historical temperature data does not contain the necessary information, even after being waterboarded into confessing to AGW.
Thanks for your thoughtful feedback.
Cheers, Kevin.
“”””” Kevin (not a PHD) says:
February 23, 2011 at 5:21 pm
In Reply to Dan (circa: February 22, 2011 at 10:53 pm)
I agree with your statements. I try to isolate what happens to a single photon (or small packet of energy) to make it more clear how the “Greenhouse Effect” cannot create any “Extra Energy”. If it cannot cause this at a microscopic scale, the fact that there are billions and billions of photons (apologies to Carl Sagan) makes no difference. And the fact that it “all happens very fast” also makes no difference.
Quoting yourself;
”We need to somehow explain why cloudy nights are warmer than clear nights and other similar phenomena.” “””””
Well Kevin (not a PhD), once again a wrong conclusion. Sure cloudy nights are warmer than non cloudy nights; other things being equal.
BUT The cloudy night is not the cause of the warmer night; it is the other way round.
The warmer moister daylight conditions the day before, set up the surface conditions for those clouds to form when the sun goes down. The hotter the surface Temepratures the day before, the higher the water vapor laden air has to rise to reach the dew point so the clouds form higher when it is hotter the day before, as is observed. Adn the lower the humidity, is the day before, the higher still that the moisture there is has to rise, so the clouds are even higher.
The surface conditions form the clouds, the clouds DO NOT form the surface conditions.
In response to George E. Smith;
I apologize if my earlier posts in reply to your insights were a little curt. I get a little sensitive about that “ignorant fool” thing (not necessarily from one of your posts, but the term was deployed here), guess I need a thicker skin sometimes.
Let me clarify a few things about EM radiation and the Laws of Thermodynamics as I understand them;
1) A single EM wave (or a photon, they are considered as equivalent explanations of observed physical effects, i.e. a duality) travelling in “free space” (sparky (electrical engineer) talk for a vacuum) is not AFFECTED by the laws of thermodynamics. Therefore it automatically complies with the laws. For example, if I walk along a road I am not affected by the speed limit, but I do comply with it, unless I’m really frisky and can beat a 5 mph limit someplace.
2) Outside of a vacuum the EM wave is affected by the laws, for example once it interacts with air some amount of the EM energy is lost by conversion to heat in the air molecules. This is one of the many reasons you can only drive so far away from your favorite radio station before the signal goes away. Usually these effects are relatively small and are ignored when a “first order” analysis is performed.
3) The laws do indeed affect multiple EM waves, for example, when two laser beams (same wavelength) meet there are locations is space where they destructively interfere. At these locations there is no energy (at least from those beams) present. However at another location (exactly 1 laser wavelength away) the beams are constructively interfering and twice the energy is present.
4) Once an EM wave (or photon) interacts in any way with matter (i.e. absorption with the ground or the gases) ALL of the laws of thermodynamics apply. Any references that refute this would be welcome, because if this is not true I will be richer than Buffet and Gates by a factor of billions and billions (hahahahaha, anybody got an emoticon for an evil laugh????)*
Cheers, Kevin.
[*Reply: “MUA-A-A HA HA HA-A-A-A!!” might work. A washing motion with your hands helps. ~dbs :- ) ]
In reply to Ira Glickstein, PhD;
I apologize if my posts have been “strong”; however I still feel that your analogy explaining the “Greenhouse Effect” has several flaws. Of course, if you have read my posts you can see my feedback.
But on another topic, here’s a good expansion on your joke;
A building inspector wants to find out the height of an office building to update the database at the department of building heights, widths, mass and attractiveness. This is in response to directive 123.21/5/8-99.2345.
He has a budget of $100 to obtain this information.
He goes to the building with an engineer, a scientist, and a car salesman.
He says I’ll give $50 to the first person that can tell me the height of this building.
The engineer runs off as fast as he can to rent a surveyors transit to directly measure the height.
The scientist quickly runs up to the roof and throws a coin off the top, He measures the transit time to the bottom and starts calculating the height of the building.
The car salesman, he runs into the building and finds the building manager, He says, Hey Buddy I’ll give you $25 bucks if you tell me how tall this building is.
Cheers, Kevin.
“”””” 4) Once an EM wave (or photon) interacts in any way with matter (i.e. absorption with the ground or the gases) ALL of the laws of thermodynamics apply. Any references that refute this would be welcome, because if this is not true I will be richer than Buffet and Gates by a factor of billions and billions (hahahahaha, anybody got an emoticon for an evil laugh????)
Cheers, Kevin. “””””
Once the photon interracts with matter (ie by absortpion with the ground or the gases) then it is no longer a photon. After that you can do with it whatever you please, and make your fortune.
And the energy in an EM wave goes as the square of the amplitude. Unless your two laser beams are generated from the same laser, they will not form standing waves; with stable amlitude zeros; they would have to be phase locked sources to do that.
But since you already know it all, then I will save my further comments for others who maybe don’t already know it all like you do.
But after ten years of formal training in Physics, including three different Physics majors in my degree, not to mention the two majors in Mathematics; followed by 50 years of in the field practicing in Industry; I seem to have become somewhat adept at convincing my several employers that I have some idea what I’m doing.
I’ve even got nine US Patent placques cluttering up my desk shelf, plus four more at home that I don’t have room for; and two more on the way from the Patent office. So they’ll probably catch up with me soon, and ask for them all back.
I’m obviously working in the wrong field.
And if you had two phase locked laser beams forming a standing wave with zero amplitude at some point, the chances are very good it will still be zero at exactly one laser wavelength away, or even at one half wavelength away. You might find a more sizeable signal just 1/4 wavelength away; well but don’t quote me on that; that is just my opinion, and I offer no references in support of that.
Frank Lee Meidere says:
February 23, 2011 at 1:02 pm
Yes, the bank transactions are a thumbnail sketch.
Q1. Did a cooler heat a warmer? A1. It’s against the law.
It’s true the law doesn’t pry that closely because they would find individual molecules becoming internally excited and having that excitement turn into external motion. If you go back up-thread Steve mentioned this.
It’s not appropriate to ask one molecule to represent all of his brothers and sisters because they are so independent-minded. At any moment a volume of air including water vapour for example has a temperature, but within that body, if you were really quick you could find a bunch of molecules so sluggish that they would qualify as ice and, right next door you’ve got some that would scald you. The reason they’re moving as they are is the collisions that have taken place. Incoming photons add some very, very local pepper but it doesn’t constitute heat until there’s a respectable amount of it. After all, there are others adjacent that are spitting out photons just as fast as they can, so that would be cooling. Except, it’s not. It’s all about the average.
In discussions we tend to visualize radiation across human-scaled distances but radiation occurs within volumes of stuff, not just between different things like “the surface” and “the atmosphere”. Conduction utterly overwhelms radiation within a steel bar. Many of us think it does in a gas at 1000 millibars.
Q2 Answered above, I hope, but the withdrawals would have to be pro-rated as the account dwindled.
Q3 Is he still missing?
You know, I think that does it. So in my banking analogy, we don’t consider the various profits and losses until the end of the day, at which point they would average out to what we would expect: BA-A ends up “cooler,” while the other two end up somewhat “warmer.” At least until equilibrium is reached.
Thank you Oscar, George, and Ira. This has helped a lot.
George, calm down, I’m not questioning your understanding of EM radiation.
Yes indeed the laser beams need to be coherent over the length of interest, and for a “stable” interference signal they need to be phase locked (most easily established from the same source, but not a necessary condition) etc. etc. This was intended to be a high level example of interference, not a detailed example including all of the caveats including; coherence length, phase matching, wavelength matching, etc. etc. My major point was that the energy at the location of destructive interference is not destroyed; it just shows up someplace else, in full compliance with the laws of thermodynamics.
This is supposed to be a “thought” experiment right ?
My point again is that the laws of thermodynamics apply everywhere (from molecules to the entire universe (however big that may be)). In some cases these laws have no apparent affect (i.e. EM waves in a vacuum). But they still apply, everywhere, everyplace, all of the time.
I do not care to get into a ——- match about who has more education and patents and experience, etc. I am glad to hear that your employer values your contributions, as does mine.
I never claimed to “know it all”, please note the beginning of my post where I said “AS I UNDERSTAND THEM”. I am certainly open to any information that increases my understanding of the laws. Telling me how many patents you have does not increase my knowledge about the laws of thermodynamics.
Cheers, Kevin.
George E. Smith, Kevin,
Thanks for your comments.
Seems even very knowledgable persons disagree on a lot of issues (or maybe the forum type of discussion can turn anything into an argument).
In my original post I tried to reconcile the observation that any form of shielding seems to slow the radiative cooling of an object, with the second law of thermodynamics which states that heat or energy only goes from hotter to cooler.
The idea that the shield is heated by the emitting object and then heats the emitter by radiation is not consistent with the second law unless you look at the process in detail like we just did.
I know this “backradiation thing” is slightly AGW-ish, (shudder) but facts are facts.
Brgds, Dan
Ira Glisckstein;
One of my favorite jokes is about the physics major and engineering major who are waiting for a bus outside a building. >>>
I think the first time I noticed this odd acceptance of mathematical results without thinking was when calculators first started becoming common. There’d be come calculation or other that needed to be done and all the slide ruler guys would say “four” just as the calculator guys would say “three point nine nine nine nine nine…”
I used to say “so…four?” and some of them would argue. I’d ask them to sell me what the difference was by subtracting four from their results on the calculator… and some of them STILL didn’t get it.
I developed a few quips over the years to make various points:
Q: If two trains are 100km apart, one going 30 km and our and accelerating at 1 km/hr/min and the other is going 20 kilometers an hour accelerating at the same rate, what will the speed of collission be?
A: What makes you think the rail company is stupid enough to have them on the same track?
For the physicists…
Q If I throw a ball straight up, and there are no other effects except gravity, what is the velocity of the ball at the peak of the trajectory?
Physicist; zero
Q Zero? Are you certain? Zero? Motionless?
Physicist; yes
Q So if it is motionless at the peak of the trajectory, how does it get back down?
And for the engineers:
Q can you model the suspension of a car with a capacitor, a resistor, and an inductive coil?
Mech Engineer; of course not
Elec Engineer; don’t be stupid
Q could you, Mr EE, write down the equations you would use to calculate current in that circuit on the white board? And could you Mr ME write down the equations for motion in a system with a spring, a shock absorber and a known coefficient of friction?
Ok, look at those equations side by side. Now, can I ask the question again?
And possibly my all time favourite
Q What is centrifugal force?
A Force outward on a body travelling in a circle
Q If I tie a string to a weight, and swing it around in circle, am I pulling on the string or pushing on it?
Hmmm, I had lots of problems with your analogy until I ready your explanation of what was left out. Now I think it’s pretty good. I think you left out something in your list of what’s left out. Maybe this has been pointed out already:
There is no heating effect merely from low-band light present in the atmosphere. In fact, you can bounce (completely “elastically”) as much IR as you like and it creates no heat. What creates the heat is the “inelastic” bouncing of IR. It strikes a surface (or a free-moving atmospheric particle) and LOSES some energy. This energy manifests as heat.
Thus your analogy is misleading as it represents the “collisions” as elastic, whereas the heating effect is entirely dependent on inelasticity. The analogy looks good insofar as it represents the amount of IR radiation passing through the atmosphere at every point but it fails at what some will consider to be the most critical point.
When I saw your first diagram I thought you were representing the heating effect as the momentum transfer from the balls bouncing off the scale. If that were the case one of your earlier questioners would have been right, in that you cannot manufacture further momentum simply by bouncing balls around in a closed system. Then as I read I decided you didn’t mean this. Then by the time I was finished, I was unsure.
Perhaps the analogy needs a “redo” taking this and a few other worthwhile objections from the comments into account. Our physical intuition concentrates, consciously or unconsciously, on momentum transfer in your analogy and this confuses the issue. In the radiative heating context momentum is practically a nonissue. I hate to tinker but perhaps you need balls with no momentum but finite weight (no, Galileo would turn over in his grave; he demonstrated that gravitational mass and momentum mass are interchangeable). Well, something like that. Or a weightless ball — someone suggested “flubber” above — that leaves “goo” behind when it bounces, and the goo has weight. the “weight” equals the heating effect. shortwave radiation leaves practically no goo, but longwave leaves much more.
Hmmm, looking at my suggestion it’s going to really mess up your simple analogy. I changed my mind. It’s a nice start, but perhaps you need a slightly different analogy, to avoid the problem with momentum.
I heard a version of that same joke during the slide rule days before calculators. For those unfamiliar with a slide rule, there are marks for two significant figures and then, to get more, you have to estimate the distance. (Like reading a clock that has no second hand and attempting to estimate seconds by the position of the minute hand.) Well, at our college, they installed really big slide rules (perhaps six feet long) at the front of the classrooms and the profs used them to demonstrate calculations. With the larger slide rule, some thought they could estimate to four or five or more significant figures.
Well the joke is that some profs got so used to the slide rules that they used them even for calculations they could do in their head. So, one time, when the prof had to multiply 2 x 2, he used the slide rule and announced the answer: "3.995, but, for convenience, we’ll call it 4.”
“”””” Kevin says:
February 23, 2011 at 8:13 pm
George, calm down, I’m not questioning your understanding of EM radiation. “””””
Is that one of those:- “Have you stopped beating your wife yet ?” statements ?
So what is your evidence that I am not calmed down; why would I be other wise ?
So where in any of my posts did I assert, or even hint that I might believe that the Laws of Thermodynamics do not apply everywhere in the Universe. Can you provide a reference for any such assertion by me ?
A similar situation is the statement often asserted by posters at WUWT, that the Heisenberg principle of uncertainty, only applies to microscopic things, and doesn’t apply in the macro world.
So those folks are asserting that in the macro world, you CAN ( in a macro situation) have dx . dp < h/2pi despite Heisenberg's assertion that you can't.
So, many folks including me, believe that the laws of Physics apply everywhere. Apparently string theorists believe that there is a separate universe for every conceivable different set of Physical laws. They of course have no proof of that; or even any evidence of such behavior; no basis whatsoever; which simply is NOT science.
So you apparently believe that not only do the laws of physics apply everywhere, but they also apply to everything; or every concept even. The question is, what experimental observational evidence accompanies the application of some physical laws; say the laws of Thermodynamics, to some physical situation, where they create no consequences whatsoever.
In fact you could rewrite the laws of thermodynamics to be anything you want them to be, and then get the same null experimental data when you apply them to some systems. You may choose to believe that those laws apply to that system; others may differ.
You may choose to have two laser beams interfere and produce zero amplitude at a specific point in space; and assert that there is no energy at that point; it is somewhere else, I believe you suggested.
Well may I counter with a suggestion that the total laser energy, at any point whatsoever in that region of overlapping laser beams, is also precisely zero. You won't find any energy at any such point whether the electric field there is zero or any finite value. And you won't find any even in a thought experiment; just as there is none there in real physical fields.
As for my quip about Patents, and such; was it not YOU who made a point of telling us that YOU are not a PhD; as if that message, was supposed to convey some important information to other readers.
Since it was you who raised the credentials issue for us all to wonder about, I simply chose to lay my cards on the table so readers can see, I have nothing up my sleeves.
One could make the point that PhDs tend to learn more and more about less and less. In my case, I elected to forgo advanced degrees, as having no value for my intended career path; and pursued a multidisciplinary career in Industry; where a working knowleedge of many subjects was of more use than an extensive knowledge of a very restriced specialty.
I have no problem with those in certain fields who DO have the need to have highly refined formal training in certain specialties.
Dr Laura has a PhD; she doesn't know anything about either EM radiation or Thermodynamics. I thought of getting one in Ice Cream Making; but couldn't find any job listings requiring that skill.
It's good that you have a job with an employer who appreciates your knowlwedge. So I don't have to worry about you coming after my job.
Thanks R. Craigen for you comments and thoughts. Physical analogies are always a problem because , if you account for everything, you end up with something as complex as the thing you are analogizing and the whole point of the exercise is to come up with somthing simpler to aid insight and understanding.
Let us consider the balls and the scale as a physical system only, in an idealized case with no gravity and perfectly elastic balls and tray. If I pitch a steady stream of balls at the tray of the well-damped weight scale, they will compress the springs. During that time period, the tray will be moving down against a force, which requires energy, so, even if the balls and the tray are perfectly elastic, and we ignore the effects of gravity, there will be energy consumed in compressing the springs, and, as a consequence, the balls bouncing off will have a little less speed than the balls coming down.
However, once the springs are compressed to the point that their force upwards exactly matches the force of the balls coming downwards, the tray will not move and there will be no energy consumed. So, the upward bouncing balls will have the same speed and energy as the downward ones.
I thought of the scale analogy while riding my bicycle, after having sketched up several versions, including one where the pitching machine was aimed horizontal and was impacting a hinged vertical plank such that it was no longer vertical. The scale analogy was pleasing because, in the case of the Sun and the Earth, when the Sun comes up and bathes the Earth in Sunlight, the portion of Sunlight absorbed slowly raises the surface temperature (like springs being compressed) until the point where surface temperature is such that an exactly equal amount of far-IR energy is re-emitted from the Earth. After that point, the Earth temperature remains constant (like the height of the tray on the weight scale) and an equal amount of energy comes into and out of the Earth (like the equality between the energy in the yellow balls and the purple ones).
Another thing I liked about the analogy is that, if I placed a fixed plank some distance above the tray, the upward-going balls would bounce off it in a downward direction, further compressing the springs until a new equilibrium was reached. To make the fixed plank more like an Atmosphere with GHG, which absorbs Far-IR energy and re-emits it in random directions, I considered having holes in the plank such that half the balls passed through (like the IR re-emitted upwards) and half bounced down (re-emitted downwards) . However, since the balls represent large quantities of energy (like the “truckloads” suggested by “PJP” whose question ignited the analogizing in the first place), I thought it better to have them split in half, going both up and down.
In any case, this thread seems to have got lots of us thinking, and some (but not all) have accepted the idea that GHG (mostly water vapor but also including CO2) in the Atmosphere are responsible for raising the temperature of the Earth above what it would be without GHG.
Some, however, seem to be so upset at the official climate “Team’s” distortions of AGW into CAGW (Catastrophic), that they do not want to accept the Atmospheric “greenhouse” effect in any way, shape, or form. In their mind, to do so, and admit that human-caused CO2 (burning fossil fuels) and land use (causing reduced albedo) are responsible for even a little additional warming, is to give AGW credibility.
I think disbelieving AGW is an error both scientifically and also in terms of winning the hearts and minds of the general public to the rational skeptic cause. I am skeptical about CAGW, not AGW. I think that CO2, per se, is not bad, and perhaps up to 1000 ppm or more might be beneficial. I think a modest temperature increase is, overall, beneficial (which is why I moved from NY to FL :^) and that the large majority of the warming we have experienced is due to natural cycles not under human control. Furthermore, the small part due to human activities is inevitable because, considering the inability of most government projects to work effectively, ther is no way we can change it much. I think it is prudent to conserve and use energy efficiently (hence my 40-50 miles/week on a bicycle and our use of an electric gold cart and a Prius hybrid) not so much for environmental reasons but because of the cost in blood and treasure to protect our access to foreign sources.
“”””” I think it is prudent to conserve and use energy efficiently (hence my 40-50 miles/week on a bicycle and our use of an electric gold cart and a Prius hybrid) not so much for environmental reasons but because of the cost in blood and treasure to protect our access to foreign sources. “””””
Ira, may I suggest that the cost (in blood and treasure) that you refer to is a domestic political decision; and not a global problem.
The US has plenty of fossil fuels to meet its needs. And our primary “foreign” source, is our nearest neighbor, Canada; with whom we share no hostilities. Our apparent shortages are of our own making; witness a dictator in Washington wh simply decrees on his royal sceptr that we shall not utilize our own energy resources.
And it isn’t for environmental reasons, because we will sit by and watch our industrial competitors, and even our enemies, come into our territorial sphere of interest, and pursue the very same resources that we refuse to use ourselves.
If you think an electric gold cart or a Prius, is an environmentally protective solution for you; then go for it. Some of us don’t see it the same way. Where I live it simply isn’t safe to commute by bicycle, although I have done that anyway.
Most of our blood and treasure expenditures go not to protect our sources; but to protect the sources of our “friends and allies” who simply won’t do it for themselves.
I would love it if we told our allies to protect their own sources of energy, and not rely on us to do it for them.
Dan, with respect;
You wrote;
“I know this “backradiation thing” is slightly AGW-ish, (shudder) but facts are facts.”
I don’t believe that I ever suggested that backradiation does not exist. I freely admit that it exists.
I also admit that “backconduction” also exists in solids (or liquids, or gases). Let me explain, a colder molecule is vibrating slowly and is in contact with a warmer molecule. The colder molecule does indeed transfer some energy (instantaneously) to the warmer molecule, however the warmer molecule transfers a WHOLE lot more energy (instantaneously) to the colder molecule. The Second law just says that the NET flow is from the warmer to the colder location; that’s all, nothing more. It does not say that energy can only flow one way, it says that the NET energy can only flow one way. Net needs to be calculated instantaneously, it is not permissible to apply “dampening” or “averages” to this calculation.
So the point is that there is nothing unique about “backradiation”. In any system energy flows in many directions all at the same time. Backradiation does not have the ability to create “extra” energy.
My point is that the AGW hypothesis calls for the creation of “extra” energy, (sometimes called “Net Energy Gain”), in the absence of better explanations from climate scientists this currently and always has violated the laws of thermodynamics.
My further point is that the fact that backradiation exists does not (by itself) demonstrate that it (backradiation) can cause a higher equilibrium temperature to be achieved. It may be able to achieve this feat, but there are many other factors that need to be investigated such as the “speed of heat” through the materials involved and the thermal capacity and volume of the materials involved.
I have a quick little analogy about AGW; I’m driving down the highway emitting mosquitoes out in front of my windshield. As this stream of mosquitoes strike my windshield they slow my forward progress and reduce my speed. So are these “extra” mosquitoes, or are the just sourced from my vehicle. This analogy is not much worse than measuring temperature with a scale (a device that only converts mass (when subjected to gravity) to a mechanical displacement).
Cheers, Kevin.
Ira says:
In any case, this thread seems to have got lots of us thinking, and some (but not all) have accepted the idea that GHG in the Atmosphere are responsible for raising the temperature of the Earth above what it would be without GHG.
Henry@Ira
Ira, the problem I have lies in the definition of a GHG. Take for instance ozone. It bounces off quite a bit of UV radiation but it also entraps some of earth’s radiation (especially at around 13um). We call ozone a GHG. But what do you say: if ozone increases in the atmosphere (which it actually does, lately), what is the net effect of this? Is it more cooling or more warming?
(straight answer please)
Henry;
You might like to specify high- or low-level ozone. They are quite separate in virtually all respects.
By “level” I mean altitude, of course, not quantity.
Ozone (O3) has a very narrow peak absorption in the longwave band of interest and is thus technically a GHG, even though its contribution to warming the Earth is miniscule and may be counteracted by its blocking of UV in Sunlight. I do not know what the net effect of an increase in O3 would be, but I am pretty sure it is very small either way.
When we speak of GHG in the context of any significant amount of warming, we generally mean H2O (water vapor), the most important and influential GHG, and CO2 (carbon dioxide), which is the next most heavy hitter. CH4 (methane) and NO (nitrous oxide) , along with O2 (oxygen) and your example O3 (ozone) are minor players with narrow peaks, as far as I know.
Water vapor, when it condenses in the Atmosphere, forms clouds that I and most other skeptics believe have a net negative feedback effect. The official climate Team models clouds as a positive feedback, which I believe makes their predictions incorrect. Their estimates of CO2 sensitivity (the increase in global mean temperature due to a doubling of CO2) are, IMHO, at least four times too big. They seem to believe that CO2 interacts with H2O in a way that multiplies its effect, and that may tie into their modeling of clouds as positive feedback. Some commenters in this thread seem to think that Atmospheric CO2 has a cooling effect, but I have not seen that confirmed. Is that answer straight enough?
henry @ BrianH
We know that most ozone is made from naturally from oxygen and UV. We need that.
Henry@Ira
if you study the atmospheric aborption bands (excluding clouds) , you will find that ozone cuts a significant part (ca. 15-20%) of the sun’s radiation. It also makes a significant dent in the outgoing radiation of earth (@ 13u).
so with the good comes some of the bad. Surely, looking purely at those graphs, I would say the net effect of more ozone must be cooling rather than warming. So why call it a GHG?
We should call it something else.
Co2 and even methane cool the atmosphere as well. You can find the proof here.
http://wattsupwiththat.com/2011/02/20/visualizing-the-greenhouse-effect-a-physical-analogy/#comment-605627
In the case of CO2, the question is what is the net effect, cooling or warming?
If the net effect is cooling, then why do we still call it a GHG?
HenryP;
As I mentioned elsewhere, Mars has 1% of Earth’s atmospheric density, but it’s pure CO2, making it 25-30X as much of a CO2 “blanket”. But the blackbody theoretical temp and the actual surface differ by only 0.1°C, and, IIRC, it’s LOWER on the surface than the bb number (280.0K vs 280.1K).
Oops!
Thank you Kevin for an interesting conversation.
Regards,
Dan
I’m pretty sure back-radiation exists. And back-back-radiation and back-back-back-radiation and even back-back-back-back-back-back-radiation.
Kevin;
My point is that the AGW hypothesis calls for the creation of “extra” energy, (sometimes called “Net Energy Gain”), in the absence of better explanations from climate scientists this currently and always has violated the laws of thermodynamics.>>>
I’m a hardcore skeptic and that is exactly what I believed when I first starting reading the science supporting AGW. I remain a skeptic, but the above is not the claim AGW science makes. In Ira’s model, and in the AGW claims, and in the IPCC reports, the increase in CO2 results in a perturbation of the system followed by a new steady state in which the rate at which energy leaves the system per unit of time is identical to what it was before the increase. Which is exactly what the physics says should happen unless the change also affects the amount of energy being absorbed.
What does change is the temperature gradient from earth surface to top of atmosphere. Interestingly, as seen from space, unless the size of the atmosphere changes, the temperature would be seen to be identical. But the “curve” from surface to TOA would be different, same net effect or average so to speak, but a different shape.
AGW theory says the shape of that curve results in much higher temperature at surface.
I say not freakin’ likely.
henry@BrianH
thanks, yes, that adds more weight to my argument. How is that on Venus, do you know? I vaguely remember that it should be even warmer if CO2 were a GHG.
henry@OliverR
I actually did some thinking about that. What I see is happening, is this: let some of the 14-15 um radiation be sent back to earth by the CO2. When it comes back (after that same radiation hits something on earth) it seems to be always coming back from earth at a longer wave length (mostly by-passing the CO2 at 14-15).
So, I would say no, there is no back-back etc. radiation. There is only (one) re-radiation (deflection) of the same photons…..
But I would like to hear the opinion of other people on this blog about this. Namely if what I say is true, then the whole idea of earth’s atmosphere acting like a giant greenhouse falls in the water. There is no entrapment. There is only somewhat delayed cooling. Is that the same as warming?
Sorry David, you posted almost at the same time as me, but your post does seem like an answer for me! Thanks!
I have said it several times; and I can repeat for those who may have missed that. The claim that there is no GHG “warming” effect, due to whatever trace gas, is for me, not a hill worth dying for.
That GHGs do capture some LWIR radiation that is emitted from elsewhere (surface or atmosphere), is known Physics, and that this results in raising the atmospheric Temperature, is also well understood. OK I don’t know how accurately this has ever been pursued to the extent that quantum theory can tell us precisely what happens; but I am personaly confident that it does warm the ordinary atmospheric gases through the molecular collisions that are the manifestation of heat. I think it is quite naive to deny that much.
What happens after that is far less certain; and to me far less interesting, because I am convinced beyond any reasonable doubt that whatever happens, will be ultimately regulated by cloud modulation. H2O is basically in control of the earth’s comfort region.
I know nothing of, and have little interest in (besides natural curiosity), the various ENSOS, el nino, la ninas, AMOs and the like. I know they are significant contributors to earth local climates. I’m happy that folks like Bob Tisdale, or Bill Illis, and others here keep track of those things and come here to explain them to us. So I don’t dismiss that stuff; it’s just my skillset is not oriented to studying that; so I’m glad they do.
But I see too much exposure to ridicule by the AGW crowd, because a lot of skeptics, don’t really understand enough quite basic science (Physics) to grasp the issues; and I refuse to believe it is because they are incapable of that. They are perfectly able to understand if it is explained to them in understandable ways. If I can help in that process, my time is well spent.
Well ALL Physical models (of the universe) and ALL mathematics, are pure fictional creations of our imagination.
There is nothing in any branch of mathematics, that actually exists anwyhere in the known universe; which after all, is all we care about. We made it all up out of whole cloth; a tool box !
And the equally fictional models of our theories, are already “analogies” if you want to use that word.
So I don’t see any point in trying to create some (presumably) simpler analogy to substitute for what is already a simple concept.
To do so, is to simply introduce confusion, and false leads to aspects of the “analogies”, that are NOT compatible with the already well accepted models.
Others much smarter than we are, have already reduced the “analogies” to about their simplest state. Heed the caution of that Einstein you mentioned; when he said (reputedly), that “scientific theories should be as simple as possible; but no simpler.”
Good words to live by. Better Ira, to use your imagination to try and make the accepted “models” understandable to lay persons; than to try and invent alternatives.
HenryP :
February 25, 2011 at 4:44 am
Henry, it is never the same photon. I could argue here but I will let Dr. Feynman do it for me by having you listenen to http://vega.org.uk/video/programme/46 at 80 minutes into the video (you can just jump to that position). He does not agree with your view of photons (light– radio waves, IR, visible, X-rays, etc.) but many thoughts you are having are getting closer. Maybe we can take the next step for I want to get to the bottom of this also but only by proper physics.
BTW: for some reason other Waynes began posting under this article, Wayne and JackWayne, they are not myself, just lowercase wayne.
In reply to Davidmhoffer (circa February 25, 2011 at 4:13am);
Since someone else still seems to be interested in flogging this room temperature horse I might as well do so as well. In between bouts of shoveling the accumulated Global Warming from my driveway up here in upstate New York I have read your post with interest.
Thank you for your insight let me rephrase it to see if I have understood it correctly;
The AGW theory (as posited by Ira, the UN IPCC, and many others) is that GHGs are able to redistribute the energy into different altitudes in the atmosphere. This materially changes the “speed of heat” through the atmosphere and causes the surface/atmosphere system to achieve a new higher energy state near the surface (i.e. melting icecaps, etc. etc. etc. etc.).
Is hope this is an accurate summary ? Please correct me as necessary.
To quote your insight;
“a perturbation of the system followed by a new steady state”, I am sorry but in my experience the “perturbation” of a system (.visa. .ve. energy) requires “extra energy”, and a “new steady state” requires that this “extra energy” be forever after present, otherwise the perturbation becomes a temporary effect (i.e. the WEATHER, it’s been in all the papers).
So as I see it some interpretations of the greenhouse gas hypothesis require that;
The thermal mass of the oceans (huge), the rocks (big) and the gases (tiny) all achieve the equilibrium temperature that is determined by the miraculous ability of GHGs to absorb, retain, and also simultaneously emit IR radiation. This is very much similar to my analogy of the mosquitoes hitting your windshield being able to determine the speed of your vehicle.
An alternative explanation (not part of the much acclaimed consensus) COULD BE;
Energy arrives from the Sun, thereafter the massive thermal capacity of the oceans and the rocks accumulates this heat. The speed of heat through these portions of the system and their thermal capacities determine the “average temperature” thereafter. Very complex interactions between clouds, humidity, albedo, etc. etc. cause a chaotic system to occur. We used to call this the weather, but once some people got a hold of computers that could calculate “energy gains” they decided they had this all figured out and could tell us what would happen in 100 years with 99% accuracy (a mister Hansen comes to mind). I freely admit that I do not have the ability to tell what will happen in 100 years. But of course I am not seeking other folk’s money to pretend that I can.
Here is just a short back of the envelop calculation for the folks that might still be open to the the flaws in the Greenhouse Effect;
The time for a photon to be absorbed and converted to thermal energy: probably less than a microsecond, buts let’s say its 100 microseconds. It’s probably the same going the other way, i.e. thermal to photon.
The time for a photon to travel all the way to the top of the atmosphere (~5 miles * speed of light) = (30,000 feet * 1 nanosec/foot) = 30 microseconds.
So each pass through the atmosphere by a photon takes maybe 130 microseconds. Lets insert some wiggle room (to account for calculation errors) and say that each pass takes 1 millisecond. So if a photon has been stricken with the dreaded back/back/back/back….radiation affliction it might be delayed by 10 milliseconds.
And this can cause a higher equilibrium temperature while the sun light striking any surface of the Earth cycles from zero to a whole bunch every 86,400,000 milliseconds ?
I hereby consider this room temperature horse to be totally flogged……..
Cheers, Kevin.
Ira,
wayne’s question gave me an idea. Your juice trucks and your physical model visualize the process by which CO2 absorbs and re-emmits photons. But that isn’t wayne’s question. What wayne is asking for is a way to visualize how the process translates into temperature increase. He asked if it was “delayed cooling”. And it sort of is, but that’s not quite it. But I think I came up with a pretty simple visual that explains it. I’d like to send it to you after I get it drawn, probably tomorrow, and see if you think it makes sense. ira @ techie.com ?? wayne, if you give have an email address to share I’ll send it to you as well as it was sort of your idea.
The truth is that
a) some warming is caused by CO2 but nobody has any quantified measurements in the relevant range, i.e. from 0,02% to 0.05%. Experiments shown to me so far are all insufficient and/or without relevant value.
b) some radiative cooling is caused as CO2 also has quite a few absorptions in the 0-5 um range, but again nobody has any quantified mesurements of that
c) cooling is also caused by CO2 due to its participation in the process of photo synthesis. To carry out photo synthesis and “growth” you need warmth, hence the reason why forests do not grow at higher altitudes and latitudes.
the question is what is the net effect?
Clue: LOOK AT THE PATTERN OF MODERN WARMING
at the various weather stations. If warming is caused by greenhouse gases, you would expect minimum temperature to show more rise.
Yet, it does not!!!
henry@georgwsmith
So why are we here? What did I learn at WUWT?
We are here because we want to learn why people have said that more CO2 is bad.
From the beginning (where I believed more Co2 is bad a la Al Gore) I have now arrived at a point where I believe more carbon dioxide is not bad, it is also not only good, in fact IT IS BETTER….for everybody….
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Is that not amazing?
Sure, David, send it along to ira@techie.com. advTHANKSance!
I thought of another anology that may help wayne and Kevin (or not). Say you have a bathtub with a slightly clogged drain. You turn on the water full-force and the water level rises. The rate of water going down the drain depends on the pressure, so, as the water level rises, the water drains a bit faster until, with a foot of water in the tub, the rate of water coming in is exactly the same as the rate of water going out, and the tub stays at 12 inches forever, so long as the rate coming in and the clog in the drain remain constant. OK so far?
Now, if you increase the clog in the drain a bit, the rate of water going out will decrease slightly, and you will have a bit more water coming in than going out. As a result, the water level will rise a bit, increasing the pressure, and that will increase the rate at which the water drains out of the tub. At some point, say 13 inches, the rate of inflow and outflow will be equal.
OK, the rate of water coming in represents the rate of shortwave (visible and near-visible light) energy from the Sun coming in to the Earth. The level of water in the tub represents the amount of heat energy stored in the Earth system (temperature of the mass of the oceans, land, atmosphere, …). The rate of water going out represents the rate of longwave (far IR radiation) going out of the Earth’s Atmosphere into Space.
The clog in the drain represents the level of GHGs that slow down the rate of energy loss from Earth to Space. Increase that clog a bit, and, all else being equal, the water level will rise until the extra pressure restores the rate of water going out and stabilizes at a new, higher level. Increase GHGs a bit, and, all else being equal, the Earth’s average temperature (of the mass of the oceans, land, atmosphere, …) will rise until the extra longwave radiation restores the rate of energy going out and stabilizes at a new, higher level.
Of course, all else is not equal. When temperatures rise there may be more water vapor evaporated into the Atmosphere and that may result in more clouds and, if clouds have a net cooling effect (as I think they do) that may reduce the rate of incoming shortwave radiation and thus reduce incoming energy rates such that the temperatures will not rise as high. On the other hand, more water vapor in the Atmosphere, with H2O being the most important GHG, may further slow the rate of energy loss from Earth the Space and cause further temperature increase.
The official climate Team says that water vapor feedback has a net positive effect, which is why they estimate the sensitivity of doubling CO2 as high as they do, +2ºC to +5ºC. Some prominent skeptics estimate CO2 sensitivity as four to ten times less, +0.25ºC to +1ºC. But, from what I have read, all climate experts, including prominent skeptics, estimate CO2 sensitivity to be positive.
Now, I am not a climate scientist (and I do not even play one on TV or at WUWT :^), so I cannot be sure about any of this (and I doubt even climate scientists can be sure, witness the wide differences in their estimates and predictions). However, I am a System Engineer who is used to dealing with very complex military avionics systems with extremely complex subsystems and components and feedbacks. I am used to dealing with differing estimates from experts in various domains of communications, navigation, and computer technology, human factors, aerodynamics, and so on. My conclusions are based on my experiences and the available data, and I have a fairly good track record with complex systems, but none of them were related to climate.
The experiences of WUWT commenters differs from mine and you may have access to different data, so we may each reach different conclusions. The absolute truth will not be known for a century, if ever, but we may get some good indications if the coming decades see stabilization of temperatures despite what seems inevitable CO2 increases, which will argue for a much lower level of CO2 sensitivity than estimated by the official climate Team.
NONE of the above argues that moderately rising levels of CO2 and/or moderate temperature increases are bad. Indeed, they will certainly be beneficial for some portion of the Earth’s population, perhaps a majority. This thread is strictly dedicated to showing that the Atmospheric “greenhouse” effect does operate to keep the temperature ranges on Earth in the livable range, and that GHG are esssential to that purpose.
Ira,
I sent the slide deck to you at that address, please let me know if you got it or not. Once I got it done, I took my own run through it and thought hmmm… wayne’s “delayed cooling” isn’t quite right, but its awfull darn close!
[SNIP – Duplicate comment]
Ira says,
But, from what I have read, all climate experts, including prominent skeptics, estimate CO2 sensitivity to be positive.
Henry@Ira
You cannot rely on that. Here, you have to come with results. We need actual measurements with actual results. [SNIP – See Godwin’s Law – Ira]
We know that most of the increase in CO2 occurred during the past 30 or 40 years. So, if you are right we should see some warming. Now carefully read my report, here.
http://www.letterdash.com/HenryP/assessment-of-global-warming-and-global-warming-caused-by-greenhouse-forcings-in-pretoria-south-africa
the finding is: there is no warming. Mean temps. have stayed exactly the same over the past 37 years. …. Max. temps have been rising but at the same time minimum temps have been falling. I found the same in La Paz, Bolivia during the dry months there. It is the same in Spain. Willis checked Armagh in Northern Ireland (where they records going back 200 years).
There is no warming caused by CO2 or by an increase in GHG’s in general.
The reason for that is probably that the radative cooling by CO2 (as proven) and the cooling caused by nature due to CO2 (by taking part in photo synthesis, as proven) cancels the warming that is caused by the CO2…..
Now, unfortunately, unless you have different measurements, you cannot claim that I am wrong.
FYI
Apparently since 1987, there has not been as much ice in the Ostsee (the sea between Poland and Scandinavia). If the cold weather there continues, you soon will be able to walk from Poland to Sweden.
Just to sign off here:
Science is not like politics, or elections or the number of votes for a person or position. In science you really only need one man who happens to be right……
Your argument has a logical fallacy, IMHO. Example: All experts say computers are made of metals and plastics. Therefore, an increase in cost of these raw materials will have the effect of increasing the cost of computers. However, over the past 30 years, the cost of computers has decreased, despite an increase in the cost of the raw materials. Therefore, the experts are wrong, and computers are not made of metals and plastics.
Global mean temperatures are affected by many factors, mostly natural cycles, but also including levels of GHG, including CO2. The fact that temperatures have stabilized and even decreased over the past decade and a half, while CO2 continues its rapid rise, is an indication that CO2 sensitivity as been overestimated by the official climate Team, but it does not mean that CO2 has a zero or negative effect.
In my example, the cost of raw materials is undoubtedly a factor in the cost of computers, but, despite an increase in that aspect of cost, other, stronger factors, such as the efficiency of mass production, distribution, online sales, and other cost-cutting effects fueled by competition, have reduced the net cost.
Ira, your model takes it as generally accepted science that the CO2 molecule is opaque to infra red and transparent to UV and visible light. The facts are: it is not transparent at a number of places from 0 to 5 um where the sun shines. You can check that. I have shown you that they can actually measure (some of ) this radiation as it is mirrored back again from the moon. Nobody has actually proven scientifically that the warming (due to entrapment of earth’s radiation between 14-15) is bigger than the cooling (due to deflection of the sun’s radiation at various places between 0 and 5 um). In addition, as also shown to you, the carbon dioxide causes cooling due to its participation in photo synthesis.
so where are the test results that would prove to me what the net effect is of the warming and cooling of the CO2 in the atmosphere? What they actually did at the IPCC is look at the increase in warming since 1750 and then correlate this to an increase in GHG’s and the CO2 since 1750. Then they came up with a “value” for forcing. But THAT IS PUTTING THE HORSE BEHIND THE CARRIAGE. There were no test results (that I could find)
Check my post here.
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
wayne
I’ve posted an article and series of slides in response to your question about “delayed cooling” here. I think that may be a reasonable term in fact, but this should provide you with a more detailed depiction of what happens (IMHO) and hopefully answers your question.
http://knowledgedrift.wordpress.com/2011/02/27/co2-exactly-how-does-it-warm-the-planet/
HenryP;
so where are the test results that would prove to me what the net effect is of the warming and cooling of the CO2 in the atmosphere?>>>
There are plenty of test results that are credible in the IPCC reports. I long since began accepting Doubling CO2 = 3.7 watts/m2 as being a reasonable approximation. My quibble is the misleading manner in which the credible testing is then presented. They calculate a 1 degree temperature increase as a result, but only in the fine print do you learn that isn’t at earth surface, it is at the “effective black body temperature” of earth, which is about 35 degrees colder than earth surface. Then they state in the fine print that this may not correlate to changes in earth surface temperature. Then they proceed to discuss earth surface temperature as if it does. They document that the effect is logarithmic, but then construct economic “scenarios” based on various temperature increases, carefully ignoring any mention of just how massive an amount of oil would have to be burned to achieve that.
You are correct, CO2 has narrow absorption bands near 2μ, 3μ, 4μ, and 5μ which are in the part of the near-IR and mid-IR spectrum where the Sun radiates. However, since the Sun’s radiation peaks at around 0.5μ, the amount of radiation in those outlying and narrow bands is greatly diminished. So, I accept your point that CO2 does reflect a small amount of Sunlight back to Space, preventing it from warming Earth. Thus, increasing levels of CO2 will increase that reflection. But, IMHO, that factor is so small it in not significant in the larger picture.
The amounts of energy reflected by CO2 to Space are so small, compared to the amounts of energy in the approximately 12μ to 17μ LW band that are reflected back to Earth that the conclusions are scientifically accepted and correctly so IMHO. As for the energy absorbed in photosynthesis when CO2 (which as I wrote on WUWT is PLANT FOOD) is taken up by plants does cool the Earth and absorb CO2. However, when the plants are consumed as food by animals, or when they die and rot, or when they are burned as fossil fuels, both the CO2 and energy are returned to the Atmosphere. Therefore, over the long term, the photosynthetic cooling and CO2 sequestration effects are cancelled out.
Bottom Line Henry: I am on your side in that I do not think there is any kind of Global Warming “tipping point” or “runaway warming” crisis, nor has there been one. The official climate Team has distorted the temperature record and the science behind the Atmospheric “greenhouse” effect in a way that violates academic integrity. But, that does not mean everything they say is wrong. Even a stopped clock is correct twice every day :^)
Thanks Dave, I read and highly recommend the CO2 posting on your blog. I also recommend your humorous and all too-true Physicist and Climatologist topic, as well as the other climate-related materials on your blog. THANKS!
Henry@Ira
Most recentlty they also discovered absorptions of CO2 in the UV range, which they now actually use to find CO2 and measure it on other planets. You forgot about that.
The absorption band of Co2 at 2 and in the 4-5 range is not that small. From a few good graphs, you are able to see that it does eat in the sun’s output. And although the sunshine intensity is low at between 4-5, that radiation is in fact very hot. A lot of the sunshine when measured in W/m2 is still in IR (43-45%). Here, in Africa, you can not stand in the sun for longer than 5 minutes. And then you look for cover. It is too hot. Admittedly, CO2 also absorbs between 14 and 15 (not 12-17). But water vapor also absorbs here as does oxygen/ozone. How do you disentangle that?
Another interesting observation I made here (in Africa) is that the heat on the skin from the sun decreases as humidity rises. (clouds do the same thing, of course),
So this confirms my observation that without the CO2 in the atmosphere even more heat would be slammed on top of us. So my question is: how much cooling and how much warming is caused by the CO2 in the atmosphere?
Your argument about the cooling caused by vegetation made some sense to me. However, it is also true that people have made living spaces in places that were once desert or semi desert. Las Vegas and Johannesburg are examples. Johannesburg is now a city that has the most trees in Africa. They brought water in and planted the trees. So your argument there also falls away and now (the last 50 years or so) you do have to take into account the cooling caused by (more) vegetation. Note that earth has become a lot greener during the past few decades (which is good).
Henry@David
there are no real test results. Ira’s argument that the “cooling caused by CO2″ is neglegible is what I have heard often, but there are no test results from real experiments. Everyone repeats the same mistake made by Arrhenius over and over again. He ignored the cooling. He did not know about it. Hence, the reason why his formula did not work (at all).
If you have experimental results I would love to hear about it. But I know what you will find. It is all just based on correlations, mathematical calculations and computer models, all based on the pre-assumption that the increase in CO2 caused (most of) modern warming…..
What I need to see is experimental measurements showing the cooling and warming in W/m2 per 0.01% CO2 per M3 dry air per time unit and the same for water vapor of course, as well as the measurements of the interaction of water vapor and CO2 on heat retention (when you mix the two)
Again I want to say that we need a complete re-think and re-measurement of everything that we thought was ‘the law”. I am more and more convinced earth needs more carbon dioxide, not less, if we want to go greener. But we need to change people’s minds. Big time.
#We can only do that if we present real experimental evidence.