Guest post by Ira Glickstein
The Atmospheric “greenhouse effect” has been analogized to a blanket that insulates the Sun-warmed Earth and slows the rate of heat transmission, thus increasing mean temperatures above what they would be absent “greenhouse gases” (GHGs). Perhaps a better analogy would be an electric blanket that, in addition to its insulating properties, also emits thermal radiation both down and up. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because GHGs absorb outgoing radiative energy and re-emit some of it back towards Earth.
Many thanks to Dave Springer and Jim Folkerts who, in comments to my previous posting Atmospheric Windows, provided links to emission graphs and a textbook “A First Course in Atmospheric Radiation” by Grant Petty, Sundog Publishing Company.
Description of graphic (from bottom to top):
Earth Surface: Warmed by shortwave (~1/2μ) radiation from the Sun, the surface emits upward radiation in the ~7μ, ~10μ, and ~15μ regions of the longwave band. This radiation approximates a smooth “blackbody” curve that peaks at the wavelength corresponding to the surface temperature.
Bottom of the Atmosphere: On its way out to Space, the radiation encounters the Atmosphere, in particular the GHGs, which absorb and re-emit radiation in the ~7μ and ~15μ regions in all directions. Most of the ~10μ radiation is allowed to pass through.
The lower violet/purple curve (adapted from figure 8.1 in Petty and based on measurements from the Tropical Pacific looking UP) indicates how the bottom of the Atmosphere re-emits selected portions back down towards the surface of the Earth. The dashed line represents a “blackbody” curve characteristic of 300ºK (equivalent to 27ºC or 80ºF). Note how the ~7μ and ~15μ regions approximate that curve, while much of the ~10μ region is not re-emitted downward.
“Greenhouse Gases”: The reason for the shape of the downwelling radiation curve is clear when we look at the absorption spectra for the most important GHGs: H2O, H2O, H2O, … H2O, and CO2. (I’ve included multiple H2O’s because water vapor, particularly in the tropical latitudes, is many times more prevalent than carbon dioxide.)
Note that H2O absorbs at up to 100% in the ~7μ region. H2O also absorbs strongly in the ~15μ region, particularly above 20μ, where it reaches 100%. CO2 absorbs at up to 100% in the ~15μ region.
Neither H2O nor CO2 absorb strongly in the ~10μ region.
Since gases tend to re-emit most strongly at the same wavelength region where they absorb, the ~7μ and ~15μ are well-represented, while the ~10μ region is weaker.
Top of the Atmosphere: The upper violet/purple curve (adapted from figure 6.6 in Petty and based on satellite measurements from the Tropical Pacific looking DOWN) indicates how the top of the Atmosphere passes certain portions of radiation from the surface of the Earth out to Space and re-emits selected portions up towards Space. The dashed line represents a “blackbody” curve characteristic of 300ºK. Note that much of the ~10μ region approximates a 295ºK curve while the ~7μ region approximates a cooler 260ºK curve. The ~15μ region is more complicated. Part of it, from about 17μ and up approximates a 260ºK or 270ºK curve, but the region from about 14μ to 17μ has had quite a big bite taken out of it. Note how this bite corresponds roughly with the CO2 absorption spectrum.
What Does This All Mean in Plain Language?
Well, if a piece of blueberry pie has gone missing, and little Johnny has blueberry juice dripping from his mouth and chin, and that is pretty good circumstantial evidence of who took it.
Clearly, the GHGs in the Atmosphere are responsible. H2O has taken its toll in the ~7μ and ~15μ regions, while CO2 has taken its bite in its special part of the ~15μ region. Radiation in the ~10μ region has taken a pretty-much free pass through the Atmosphere.
The top of the Atmosphere curve is mostly due to the lapse rate, where higher levels of the Atmosphere tend to be cooler. The ~10μ region is warmer because it is a view of the surface radiation of the Earth through an almost transparent window. The ~7μ and 15μ regions are cooler because they are radiated from closer to the top of the Atmosphere. The CO2 bite portion of the curve is still cooler because CO2 tends to be better represented at higher altitudes than H2O which is more prevalent towards the bottom.
That is a good explanation, as far as it goes. However, it seems there is something else going on. The ~7μ and ~15μ radiation emitted from the bottom of the Atmosphere is absorbed by the Earth, further warming it, and the Earth, approximating a “blackbody”, re-emits them at a variety of wavelengths, including ~10μ. This additional ~10μ radiation gets a nearly free pass through the Atmosphere and heads out towards Space, which explains why it is better represented in the top of the Atmosphere curve. In addition, some of the radiation due to collisions of energized H2O and CO2 molecules with each other and the N2 (nitrogen), O2 (oxygen) and trace gases, may produce radiation in the ~10μ region which similarly makes its way out to Space without being re-absorbed.
There is less ~15μ radiation emitted from the top of the Atmosphere than entered it from the bottom because some of the ~15μ radiation is transformed into ~10μ radiation during the process of absorption and re-emission by GHGs in the atmosphere and longwave radiation absorbed and re-emitted by the surface of the Earth.
Source Material
My graphic is adapted from two curves from Petty. For clearer presentation, I smoothed them and flipped them horizontally, so wavelength would increase from left to right, as in the diagrams in my previous topics in this series. (Physical Analogy and Atmospheric Windows.)
Here they are in their original form, where the inverse of wavelength (called “wavenumber”) increases from left to right.
Source for the upper section of my graphic.
Top of the Atmosphere from Satellite Over Tropical Pacific.
[Caption from Petty: Fig. 6.6: Example of an actual infrared emission spectrum observed by the Nimbus 4 satellite over a point in the tropical Pacific Ocean. Dashed curves represent blackbody radiances at the indicated temperatures in Kelvin. (IRIS data courtesy of the Goddard EOS Distributed Active Archive Center (DAAC) and instrument team leader Dr. Rudolf A. Hanel.)]
Source for the lower section of my graphic.
Bottom of the Atmosphere from Surface of Tropical Pacific (and, lower curve, from Alaska).
[Caption from Petty: Fig. 8.1 Two examples of measured atmospheric emission spectra as seen from ground level looking up. Planck function curves corresponding to the approximate surface temperature in each case are superimposed (dashed lines). (Data courtesy of Robert Knutson, Space Science and Engineering Center, University of Wisconsin-Madison.)]
The figures originally cited by Dave Springer and Tim Folkerts are based on measurements taken in the Arctic, where there is far less water vapor in the Atmosphere.
[Fig. 8.2 from Petty] (a) Top of the Atmosphere from 20km and (b) Bottom of the Atmosphere from surface in the Arctic. Note that this is similar to the Tropical Pacific, at temperatures that are about 30ºK to 40ºK cooler. The CO2 bite is more well-defined. Also, the bite in the 9.5μ to 10μ area is more apparent. That bite is due to O2 and O3 absorption spectra.
Concluding Comments
This and my previous two postings in this series Physical Analogy and Atmospheric Windows address ONLY the radiative exchange of energy. Other aspects that control the temperature range at the surface of the Earth are at least as important and they include convection (winds, storms, etc.) and precipitation (clouds, rain, snow, etc.) that transfer a great deal of energy from the surface to the higher levels of the Atmosphere.
For those who may have missed my previous posting, here is my Sunlight Energy In = Thermal Energy Out animated graphic that depicts the Atmospheric “greenhouse effect” process in a simlified form.
I plan to do a subsequent posting that looks into the violet and blue boxes in the above graphic and provides insight into the process the photons and molecules go through.
I am sure WUWT readers will find issues with my Emissions Spectra description and graphics. I encourage each of you to make comments, all of which I will read, and some to which I will respond, most likely learning a great deal from you in the process. However, please consider that the main point of this posting, like the previous ones in this series, is to give insight to those WUWT readers, who, like Einstein (and me :^) need a graphic visual before they understand and really accept any mathematical abstraction.
Joel Shore poses the interesting proposition
…….”If we put you in a time warp and sent you back a half century or so”…….
Well we would be back in the “Ice Age” that’s right, back then, a new ice age was confidently predicted on the basis of the then recent temperature trend.
So it appears nothing much has changed!
Hans says:
March 12, 2011 at 7:47 pm
Phil. says:
March 11, 2011 at 10:22 pm
“What on earth is the ‘quality’ of radiation?”
Which is nothing to do with the radiation, you can’t tell me what the ‘quality’ of 5μm radiation is for example.”
It is related to it’s temperature of origin, radiation energy density in J/m^3.
So it’s the quality of the source, not the quality of the radiation.
There’s no difference between a 5μm photon from the earth and one from the sun.
So not surprising related to the Stefan-Boltzmann equation (SB times 4/c).
For the LWR coming from 5777 K resulting in 0.84 J/m^3
For the SWR from earth surface at 255 K in 0.32 * 10^-5 J/m^3
Oliver Ramsay says:
March 12, 2011 at 11:54 pm
@ur momisugly davidmhoffer
“The dispute has been about whether cold things HEAT hot things.
You don’t appear to have grasped that and so, repeatedly bemoan the obtuseness of people that don’t believe that all things radiate in random direction.
WE DO BELIEVE THAT!
Tell us about how the absorption of those photons raises the average kinetic energy of the absorbing matter.”
You are correct I believe. Although cold things can radiate energy into warm things, they can’t raise the temperature of warm things. Since heat flow is proportional to the gain or loss of temperature then ergo, heat from cold things cannot flow into warm things, even by radiation.
However, this in no way invalidates the GHG idea. First, the Earth is not a closed system as per the definition in the second law, since solar energy is entering continuously. Without the sun, the temperature of the warmer ground would cool down and equilibriate with the colder atmosphere, despite the back radiation. With the sun’s input, the temperature of the Earth stays within a certain range (actually, it varies quite a lot, but the average temperature is more nearly constant). The back radiation does NOT raise the temperature of the Earth’s surface. What it does is slow the rate of heat loss into space. It is the SUN that then raises the Earth’s temperature. Voila!
Ken Coffman says:
This is just a silly game of “gottcha” on your part. It is clear that when Ray Pierrehumbert opened the Physics Today article with that statement, he meant it to be a counter-factual statement that just gave his scientific audience an order-of-magnitude idea of how much accumulated energy from the sun there would be if the earth did not re-radiate the energy that it receives. Obviously, his scientific audience would understand that such temperatures are not physically possible without the entire earth becoming a plasma or something of that sort (and, there is no reason to believe that the specific heat would be constant over such a huge temperature range, etc., etc.)
If you want to see really silly statements that are not meant as counterfactual order-of-magnitude explanations, I suggest you look no further than the co-authors of the “Slaying the Dragon” book that you link to, as I pointed out to Domenic above.
Domenic says:
Wow…You really whacked the heck out of a strawman there! Now, could you kindly tell me where it is said that on an earth with a troposphere with huge convective transport mechanisms, it has been stated that the local temperature is determined by the local amount of CO2 at that point? I find it ironic that many skeptics complain that scientists ignore the importance of convection when they do so only when they can (when considering the heat transfer between the earth and space). Yet here, you completely ignore it when you can’t.
Bryan says:
The fact that there is a lot of water does not negate the First Law of Thermodynamics. It can mean that the diurnal and seasonal temperature swings will be smaller on the Earth than on the moon but you still have to have radiative balance.
As for volcanoes, do you have any evidence that the estimates for the amount of heat due to these are off by the orders-of-magnitude that would be necessary for they to become significant in the radiative balance? (It is also basically irrelevant because the satellite data we have clearly show how the earth is radiating energy and that it is doing so according to our understanding of how greenhouse gases affect the radiative balance.)
Ah yes! The “They predicted an Ice Age” myth rears its head!
Oliver Ramsey says:
First of all, the Second Law is not a statement about whether the heat absorbed causes a temperature change. The Second Law would rule out heat flowing spontaneously (i.e., with no input of work) from a colder to a hotter even if the heat from the colder was being used to melt the hotter object without causing its temperature to change.
Second of all, in all the cases being talked about, whether it is the greenhouse effect or a person in an igloo, the heat flow IS from the hotter object to the colder object. (Some people would put “net” in front of heat flow, although others argue that this is a bit redundant since heat is a macroscopic concept.)
The reason you can warm up if you insulate yourself better (with an igloo, a down sleeping bag or what have you) is that you are producing heat and the purpose of the insulating object in question is not to “send you” heat but to reduce your rate of heat loss and thus change the radiative balance that determines what your final temperature is. The reason that reduction of heat loss occurs is due to the so-called “back radiation” but the net effect is that heat is still flowing away from you…just not as quickly as it would without said back-radiation. So, it becomes somewhat of a philosophical argument as to whether the insulating body is causing your temperature to increase…It is in the sense that if one adds the insulating body your temperature can warm up from what it was before the body was there; however, this temperature rise can only occur because your body is generating heat.
The situation with the greenhouse effect is totally analogous with the one minor difference being that the earth is not producing the energy it receives from the sun itself, but rather is receiving it from the sun.
I actually play Flanders and Swann for my students when I teach them about the Second Law. It’s not clear whether they enjoy it that much…but I certainly do!
Phil.
“What on earth is the ‘quality’ of radiation?”
You really are trying to get out of a hole you have dug for yourself.
The radiation arriving from the Sun (Solar radiation) has a higher “quality” than the approximately equal quantity of LWR leaving Earth for space.
Hans did the efficiency calculation above.
Now you can also say that the Sun is a source of higher “quality” energy than the radiative “quality” energy produced by the Earth.
The point is both “quality” statements are just different ways of saying the same thing.
It makes perfect since for someone for instance who is designing a solar energy capture system to be concerned about the “quality” of the radiation collected.
It also makes sense for them to write papers for learned journals and use the term “quality” of radiation and expect the readership of the journals to understand what is being said.
So what point were you trying to make again?
Vince Causey says:
“The back radiation does NOT raise the temperature of the Earth’s surface. What it does is slow the rate of heat loss into space. It is the SUN that then raises the Earth’s temperature. Voila!”
———————–
I rather hate to do this, seeing the anguish that has arisen around the ‘heat’ business but…
if you’ll indulge me a little further in my punctilious pursuit of precision….
I’m not happy with “It is the SUN that then raises…”
The sun doesn’t do anything different from before, so having it as the subject of the transitive verb “raise” risks the undesired connotation that it, in fact, does.
It is still akin to the statement “back-radiation heats the Earth”.
We know that the sun provides all the energy.
We know, too, that having an atmosphere results in a warmer Earth, just as an atmosphere without an Earth would be a colder atmosphere, but the devil is in the details.
It’s my contention that loose turn of phrase leads to attempts to justify a premise that never really was. Maybe like the Second Law not applying to radiation!
kforestcat says:
Been there…Done that…Have the t-shirt. I spent 13 years in industry and only recently have made the shift to the academic world.
My point is not that your training is out-of-date. My point is that some of your statements might have applied in the early days of the modeling of the heat transfer in the atmosphere but that they don’t apply to how it is done now.
There are, of course, models at lots of different levels of detail. But, my point was simply that the statements that you made about the handling of heat transfer by the models may be true for some of the simpler models but are not true for the modeling actually used to determine the radiative forcing due to greenhouse gases.
Well, Dave, this may be the first time we have not agreed!
In my Tale of the Global Warming Tiger WUWT posting, I estimated that the supposed warming since 1880 of 0.8°C by the official climate Team could be divided into 0.3°C for Data Bias, 0.4°C for Natural Cycles and Processes, and only 0.1°C for AGW.
WUWT readers were asked to comment and I combined all of their estimates in a spreadsheet at Global Warming is a Pussy Cat and, guess what? The average for all WUWT readers who responded was HIGHER than my estimate and came in at 0.18°C for AGW, nearly twice my original estimate. Therefore, far from being a case where “The planet hasn’t noticed” AGW is most likely to be a substantial percentage of the actual warming since 1880.
If you stole that percentage of Bill Gate’s fortune, I think he would notice!
Of course, 130-odd years is a drop in the bucket compared to the age of the Earth or even of human habitation here, but, it is longer than my lifetime, and yours. On the other hand, if we get a couple of decades of cooling, due to natural cycles, as we may if there are a couple of low Sunspot cycles and Henrik Svensmark’s cosmic ray theory turns out to be correct, we may well be thankful for the AGW.
Oliver Ramsay,
“It’s my contention that loose turn of phrase leads to attempts to justify a premise that never really was. Maybe like the Second Law not applying to radiation!”
I don’t have an argument with that.
“The sun doesn’t do anything different from before, so having it as the subject of the transitive verb “raise” risks the undesired connotation that it, in fact, does.”
You have come 90% of the way, yet still missed the conclusion. The sun, of course, radiates just as before, but when you add the back radiation from GHG, you arrive at a figure for radiation at the Earth’s surface which is greater than that without the GHG. As per Stefan-Boltzman, higher radiation flux must lead to a higher temperature.
Now, you may object that this amounts to the notion that the cooler atmosphere is heating the Earth, which violates the second law and contradicts my previous statement that a cooler object cannot heat a warmer object. But SB is clear – if you increase the radiative flux, the temperature must rise. So what is to be done with this connundrum?
Oliver Ramsay;
I’m curious Oliver. Do you enjoy being a punching bag? I’m not “angry”, amused is more like it. Just because I keep hitting a punching bag doesn’t mean I’m angry. I have no idea if you are angry or not. I do know that you’ve attempted to discredit my explanation from a number of different angles, and I’ve shown that each of them was invalid. You’ve attributed to me things I never said, and ridiculed me for them. You’ve attacked me with improbable interpretations of what I said presented with dripping sarcasm, and then complain that I’m treating you like you are stupid when I respond in kind. I’ve addressed the flippant remarks with the scorn they deserve, but I’ve answered every technicality you raised also. In fact, your complaint directed at my parable complete with rocker arm assemblies was in answer to your question as to why I felt so compelled to keep debating the matter and your conclusion that it must be because I am lonely. Now you assume the imaginary conversations in my parable suggest I take you for an idiot. This from the man who accused me of building igloos that would cause spontaneous human combustion.
Frankly Oliver, I think I’ve been rather civil. I can take the gloves off if you want, but am reluctant to do so given your obvious sensitivity to being portrayed as an idiot when I rebutt idiotic statements that you’ve made. I can’t imagine how much your feelings might be hurt if I was actually trying to do that, or what other evidence your retorts might then contain of this malady with which you may be afflicted.
In your last stinging retort, you admitted that:
“Cold things radiate a warm things”
Then you said
“Tell us about how the absorption of those photons raises the average kinetic energy of the absorbing matter.”
Well, didn’t you just explain it yourself? The photon carries energy. It has a mass of zero. It gets absorbed by a piece of matter. Since this changes the mass of the matter by zero, but increases the amount of energy by what the photon was carrying, it now contains more energy than if the photon had not been absorbed. The total amount of energy that piece of matter contains may in fact be dropping over the given time period during which that photon was absorbed, but it would have dropped even more if that photon had not been absorbed by exactly the amount of energy the photon was carrying. If the matter in question is you naked on the ice on the floor of the igloo, you will freeze to death slightly slower than you would have otherwise. If you are in a parka and snow pants, you will probably be just fine unless you are enough of an idiot to go sleep outside the igloo where your body heat just goes to waste instead of being absorbed by the igloo and some of it being radiated back to you.
What photosynthesis and vibrational modes and all the other issues you raised is immaterial. It doesn’t matter HOW the photon got absorbed, only if it did or not. Even idiots would know that.
Oliver Ramsay says:
March 13, 2011 at 9:30 am
“It’s my contention that loose turn of phrase leads to attempts to justify a premise that never really was. Maybe like the Second Law not applying to radiation!”
Read that a lot, and it’s very wrong. In this thread we have seen in quotes from papers that the Second Law applies to the photon gas in the Sun.
Planck could only solve the blackbody problem after applying the Second Law, and Einstein did the same to find the nature of radiation; quanta.
Vince Causey says:
“But SB is clear – if you increase the radiative flux, the temperature must rise. So what is to be done with this connundrum?”
——————–
Well, I’d flip your S-B and say that hotter radiates more.
Bryan says: March 13, 2011 at 1:50 am
Well we would be back in the “Ice Age” that’s right, back then, a new ice age was confidently predicted on the basis of the then recent temperature trend.
So it appears nothing much has changed!”
Bryan, all the information I have seen suggests that most scientists were still predicting long-term warming (from GHGs) in spite of the cooling of that era (that was attributed to aerosols). http://www.skepticalscience.com/ice-age-predictions-in-1970s-intermediate.htm
Could you provide citations to multiple scientific papers that “confidently predicted” an imminent ice age? Can you provide references to refute the information in the link? Or is this simply something you heard once?
Just some related stuff regarding the Second Law.
Cosmological
and Biological Reproducibility, Limits on the Maximum Entropy Production Principle:
‘To measure entropy in cosmology we just need to count photons. If the number of photons in a given volume of the universe is N , then the entropy of that volume is S ~ k N where k is Boltzmann’s constant.’
‘The maximum entropy is obtained when all the energy E is converted into minimal energy photons with wavelengths as large as the system. This is the maximum entropy condition (Bekenstein 1981): Smax = k Nmax = k E/Emin.’
And that’s the goal in the universe (Clausius: The entropy of the universe tends to a maximum.) So radiation from the Sun uses Earth to create high entropy IR radiation.
Think of the diagrams of Sun and Earth blackbody curves next to each other, the short wave length spectrum of the Sun on the left and the long wave length of Earth on the right. And clearly that is direction the photons take obeying the Second Law, from left to right.
If only the First Law ruled, any outgoing spectrum would be possible as long as it had the same total energy. And not only that, it could change position constantly at random.
Oliver Ramsay says:
March 13, 2011 at 9:30 am
“We know, too, that having an atmosphere results in a warmer Earth, just as an atmosphere without an Earth would be a colder atmosphere, but the devil is in the details.”
Yes it is, so I imagined earth without atmosphere but with a layer of GHG with a total amount equal to what it is now at any height giving backradiation. Does this heat the surface? More important, what would the temperature be between earth and the GHG layer? That would be 3 K.
Tim Folkerts,
Skeptical Pseudo-Science is simply cherry-picking what they want to let you see. You need to be more skeptical than to believe what they’re trying to sell.
It took me all of two minutes to find this information, and if I wanted to waste more time on it no doubt I would find more:
• In the mid-70’s Dr Murray Mitchell of NOAA stated that temperatures had declined half a degree between 1945 and 1968. That doesn’t sound like global warming, does it?
• Prof George Kukla of Columbia University noted a large snow increase in 1971 – 1972, and a study released in May 1975 reported a 1.3% decline in solar radiation between 1964 and 1972. That study would suggest global cooling, no?
• Dr Reid Bryson of the University of Wisconsin stated that the current decline [by 1975] had already taken the planet one-sixth of the way toward the average Ice Age temperature. Does that sound like a scientist predicting runaway global warming??
For a balanced overview of the past century, see here.
Back in the 1970’s scientists could speak out much more freely than they can today. To assume that they were all predicting global warming, when the planet had been steadily cooling, is to be credulous.
Skeptical Anti-Science is a propaganda blog run by a cartoonist. No doubt that’s how it gets the professional look. But the truth is not in them. That’s why their traffic numbers are so low. SS is just an echo chamber of like-minded, self reinforcing head-nodders. Stick around here. You will get all points of view – uncensored – at the internet’s “Best Science” site, instead of being spoon-fed John Cook’s CAGW agenda.
Tim Folkerts
Better still about the coming “ice age” as seen in about 1968.
I was a second year physics student then.
The cultural revolution in China, the little red book, events in France and the Vietnam War and the coming ice age were all discussed in the coffee bars.
Nobody mentioned “Global Warming”.
Ask anyone who was a student then and they will tell you the same story.
Only recently has there been an attempt to contradict what many people know from personal experience.
I suppose it all fits in with the elimination of the medieval little ice age and the earlier warm period around 1000AD.
We will next be told that the advice given by a senior scientist at UEA/CRU that we should take a picture of snow to show our children/grandchildren as snow falling in the UK would become an exceedingly rare event never happened.
These crude attempts to falsify history are bound to fail.
Could you provide citations to multiple scientific papers that “confidently predicted Global Warming” in the year 1968?………… – No! …….. – I didn’t think so!
Bryan, Tim, Smokey,
Paper records are a wonderful thing if you’ve got some hiding in your basement. Jo Nova has a post a while back showing the temp records published in National Geographic some time ago, which prompted me to dig through my 1974 Britannica. A quick look at both explains why the prevailing thought at the time was a coming ice age. In fact, I was in junior high and remember some kids crying because they thought they were going to have to flee the coming ice and abandon their homes.
http://knowledgedrift.wordpress.com/2010/03/17/national-geographic-1976-brittanica-1974/
Ken Coffman says:
This is just a silly game of “gottcha” on your part. It is clear that when Ray Pierrehumbert opened the Physics Today article with that statement, he meant it to be a counter-factual statement that just gave his scientific audience an order-of-magnitude idea of how much accumulated energy from the sun there would be if the earth did not re-radiate the energy that it receives. Obviously, his scientific audience would understand that such temperatures are not physically possible without the entire earth becoming a plasma or something of that sort (and, there is no reason to believe that the specific heat would be constant over such a huge temperature range, etc., etc.)
If you want to see really silly statements that are not meant as counterfactual order-of-magnitude explanations, I suggest you look no further than the co-authors of the “Slaying the Dragon” book that you link to, as I pointed out to Domenic above.
Domenic says:
Wow…You really whacked the heck out of a strawman there! Now, could you kindly tell me where it is said that on an earth with a troposphere with huge convective transport mechanisms, it has been stated that the local temperature is determined by the local amount of CO2 at that point? I find it ironic that many skeptics complain that scientists ignore the importance of convection when they do so only when they can (when considering the heat transfer between the earth and space). Yet here, you completely ignore it when you can’t.
Bryan says:
The fact that there is a lot of water does not negate the First Law of Thermodynamics. It can mean that the diurnal and seasonal temperature swings will be smaller on the Earth than on the moon but you still have to have radiative balance.
As for volcanoes, do you have any evidence that the estimates for the amount of heat due to these are off by the orders-of-magnitude that would be necessary for they to become significant in the radiative balance? (It is also basically irrelevant because the satellite data we have clearly show how the earth is radiating energy and that it is doing so according to our understanding of how greenhouse gases affect the radiative balance.)
Bryan says:
I just don’t buy this artificial construct.
The Surface of the Earth is 70% water. Why ignore this massive heat store?
The earth as a whole is about 0.023% water. On this scale, water is hardly a “massive” heat store.
Active volcanoes are also under the sea.
Estimates I have seen suggest that the average upwelling heat from the interior is about 0.1 W/m^w. Even if this number is off by a factor of 10, 1 extra W/m^2 would hardly be a major source of warming for the oceans. Do you have better info on the amount of geothermal energy?
The real test of the IPCC position is what would happen to the Earths climate if CO2 did not radiate in the Infra Red.
Looking at the satellite data at the beginning, if CO2 did not radiate, there would not be IR radiation from the cool upper atmosphere around 15 um. Instead, the warmer surface would provide MORE radiation leaving the earth at those wavelengths. The IPCC position is that more IR energy leaving the earth would cool the earth.
I suggest there would be very little difference to the present climate and if anything perhaps a little warmer.
Are you suggesting that allowing energy to escape from the surface more easily would RAISE temperatures? Could you provide some calculations to support this conclusion that is the reverse of what the 1st Law of Thermodynamics would predict?
Smokey says:
Balanced?!?! Are you serious? That is a balanced overview? The Business and Media Institute is a balanced organization? What have you been smokin’ there, Smokey?
That screed doesn’t even address the scientific literature. It simply looks at the popular media (and presumably cherrypicks there too). Here is a study about the scientific literature (with some discussion of the media too): http://journals.ametsoc.org/doi/abs/10.1175/2008BAMS2370.1 It is in a respected scientific publication and although a lot of people have tried to argue that it must not be true, that Connolley is biased etc., they have been awful short on actual counter-evidence (to any of the claims actually made in the paper).
Nice strawman. Nobody is claiming that EVERYONE was predicting global warming. What is being said is that in the scientific literature, even at a time when there had in fact been a global cooling trend (at least in the Northern Hemisphere), more scientists were expressing concerns about future warming than cooling. However, there was not yet a scientific consensus on climate change and an NAS study in the mid-70s concluded that climate change was a potentially serious issue that merited further study, and correctly identified the various factors influencing future climate, but also concluded that the science could not yet conclude which factor would dominate.
Hence, claims to the effect of, “How can we believe scientists today when they are predicting warming when 35 years ago they were predicting cooling? What if we had acted on their dire warnings then?” are nonsense. There was not yet any sort of scientific consensus on what the future held in store…and the same scientific bodies who are today in agreement that such a consensus exists…such as the NAS…were very clear in stating that it was premature to predict what was going to happen.
Thanks Dave for letting us know that people still keep paper records from the 1970’s. How long will it be before all, or nearly all, paper records are considered unnecessary?
Well, with Google scanning so many books, and providing the results so conveniently via the Internet, I predict that most paper publications will be discarded within a few decades in favor of electronic text versions and scanned copies.
In my free online novel 2052 The Hawking Plan the lack of paper records is taken advantage of by the flawed heroine. She orders changes to the electronic texts, and then, to cover up those modifications, has those same changes made to the online scanned copies of key documents. To complete the ruse, corresponding changes are ordered to the originals of certain documents stored in museums. The plan is coded-named “máquina del tiempo” which means “time machine” because, while it does not actually involve travel back in time, it achieves the same purpose by altering records from the past. The scheme unravels when an obscure museum document curator notices that changes have been made to the Dead Sea Scrolls.
It seems, from the copies of Britannica and National Geographic on your website, that the CRU [Climategate Research Unit] and other members of the official climate Team have their own máquina del tiempo plan in full operation.
“For a balanced overview of the past century, see here.”
You are expecting a balanced view on science from an organization whose mission is “to audit the media’s coverage of the free enterprise system. It is our goal to bring balance to economic reporting and to promote fair portrayal of the business community in the media.”?
The article did seem to do a respectable job of giving an overview of MEDIA portrayals of climate change (although I have no direct confirmation that the articles they quoted were indeed representative of the MEDIA coverage). But the fact remains that this was a media report about media reports — we all know taht media coverage of science is often quite poor.
“Could you provide citations to multiple scientific papers that “confidently predicted Global Warming” in the year 1968?………… – No! …….. – I didn’t think so!”
Interesting how you try to turn this around. YOU claimed that scientist confidently predicted cooling. When challenged to support your position, you mis-state my position (I merely claimed that the majority of scientific papers of the time supported warming rather than cooling) and you then ask me to do exactly what you avoided.
Still, I DID provide a link to appropriate information. The link even listed articles to support your position! if you couldn’t follow the article I linked to, here is a direct link to the actual study: http://ams.confex.com/ams/pdfpapers/131047.pdf
“Skeptical Anti-Science is a propaganda blog run by a cartoonist. ”
That might well, be, but ad hominem attacks never make for a strong argument. If you have an issue with a the page I linked to, then state specifically what you disagree with on that page or in the paper it references.
“It took me all of two minutes to find this information …
• In the mid-70′s Dr Murray Mitchell …
• Prof George Kukla of Columbia University …
• Dr Reid Bryson of the University of Wisconsin …”
All three of those quote seem to have come from the same Newsweek article — which is not a scientific journal. What scientific papers did they write? What were they predicting for the future?
“To assume that they were all predicting global warming, when the planet had been steadily cooling, is to be credulous. ”
I readily acknowledge that there was a wide variety of opinions among scientists. I linked to a paper that specifically showed a lack of consensus. But to think that there was a consensus for COOLING is also to be credulous, accepting sensationalized reports in Newsweek as an accurate summary of scientific thinking.
Next time, I’ll have to stick to the science and leave the editorializing to others.
Dear Joel
Regards your comments @ur momisugly March 13, 2011 at 10:11 am
Glad to hear you have some industrial experience. Hope your experience will better enable you to guide your students.
On to your other points. Per your comments:
“My point is that some of your statements might have applied in the early days of the modeling of the heat transfer in the atmosphere but that they don’t apply to how it is done now.”
“There are, of course, models at lots of different levels of detail. But, my point was simply that the statements that you made about the handling of heat transfer by the models may be true for some of the simpler models but are not true for the modeling actually used to determine the radiative forcing due to greenhouse gases.”
Sorry I can’t fully agree with you, the details I provided were from fairly recent papers describing GHG modeling. Moreover, looking at the larger picture, part of my duties involve consulting with professional atmospheric modelers regarding pollution deposition (Particulate, SO2, NOx, Hg, etc.). To a man these professionals indicate that the current state-of-the-art models do not accurately model regional/national/world wind flow patterns well enough to accurately predict pollution deposition. Get them to talk about GHG modeling of heat transfer and GHG effects? It hard to get them to quit laughing hard enough to tell you how many ways those models are inaccurate.
Given the current state of atmospheric modeling – abet much better than in the past – I not convinced of the accuracy of the current model used to: 1) determine radiative forcing or 2) determine their effects on the atmosphere.
Looks like this is one of those things we’ll just have to agree to disagree – in a friendly way.
Of course I’m allways open to be proven wrong. If you have additional literature you can recommend, I put it on my reading list.
Best Regards, Kforestcat