After the essays in May on mirrors and light bulbs, I’ve been regularly poked and prodded via email for not wanting to engage “the slayers” anymore, or to do that “third experiment” I mentioned in May. I long ago concluded by my experiences afterwards with “the slayers” that it is a waste of time and effort to try to explain anything to them. Curt Wilson, who did the second experiment and was planning to do the third, has come to the same conclusion, as have many others.
I have to give them credit though, they are entertaining. When I saw this profoundly ridiculous rebuttal (reflectional denial) at their headquarters while arguing over Willis’ Steel Greenhouse post, I just had to share it.
LOL! That’s the “slayers” in nutshell right there. No better example of the absurdity of their position exists in my opinion. Epic.
WUWT regular, Duke physicist Dr. Robert G. Brown has been trying to talk some sense into them over at Principia Scientific. I keep telling him he’s being sucked into a time and energy sink like gravity around a neutron star. Just as it is a good policy to steer clear of neutron stars, so it is with these folks who are incapable of assimilating the real world of physics, but live in an alternate reality of absurd second law constructs.
So, that’s why I’m not bothering anymore, when you have reflection denial statements like the one above, why engage in a pointless dialog with the hopelessly lost who don’t want to learn anything? Thank goodness for my spam filter.
For those that might care, keeping the filament of a lightbulb within its optimum temperature range increases its life, by limiting hotspots and thus tungsten evaporation. Putting an incandescent bulb into a reflector housing not designed for it will in fact increase the filament temperature, increasing tungsten evaporation and deposition on the inside bulb glass surface.
See: http://www.lightingassociates.org/i/u/2127806/f/tech_sheets/FAQs_Reflector_Design__Why_is_it_important_.pdf
Tungsten evaporation from hotspots is why standard incandescent bulbs eventually fail.
[snip – too stupid and condescending to post – Anthony]
tjfolkerts provides some very civil (thank you) comments on my own. While I’m currently traveling in the northeast and have limited access to my resources (probably shouldn’t have jumped in under the circumstances), there are a few observations regarding tjforkerts comments that I can provide.
I wrote:
“… the lightbulb would be reflecting upon itself a heat source that is being continuously renewed from an outside source! This bears no resemblance whatsoever to the “greenhouse gas” theory of the solar-Earth-atmosphere system.”
tjfolkerts responded: “The earth IS renewed by an outside source .. the sun!”
My reply: Perhaps I should have been more clear. The outside source I referred to was “outside” the lightbulb system and is the source of electric power supplied to the outlet where this “experiment” is connected to the power grid. The “source” of the radiation is the filament within the lightbulb. The electricity supplied to that filament is outside the system and completely unaffected by the foil! It will continue to supply energy to the filament so long as the bill is kept current! This is NOT analogous in any way to the solar-Earth-atmosphere system.
I wrote:
“(2) Why ice core data clearly show that atmospheric carbon dioxide RESPONDS to climate warming and is not the CAUSE of climate warming … “
tjfolkerts responded: “CO2 can be both a casue and an effect of warming…”
My reply: But THAT is the question in dispute. What “warming” are we discussing? Atmospheric warming or Earth surface warming? No dispute that atmospheric material can be warmed by solar radiation. But (a) to what extent and by what mechanism (convection? surface contact conduction? radiation?) is the atmosphere warmed by Earth during daylight hours as shown on typical charts illustrating greenhouse warming theory (which typically only address radiation), and, (b) what process allows the warmed atmosphere (regardless of source of warming) to increase Earth’s surface temperature (the 2nd LAW – not theory – contention). BTW, the 2-way notions, even if accurate, cannot ADD heat, i.e., you cannot explain away a violation of the 2nd Law so frivolously – the 2nd Law does not limit its application to any particular type of heat transfer, nor does it grant atmospheric exceptions.
tkfolkerts reply continued: “… the conditions in the last ~100 years ARE different from the past. The is an ‘unnatural’ source of CO2 (ie people).”
My response: I’ve always been fascinated by the idea that humanity is somehow “not natural” – but that is for another discussion and beside the point.
tjfolkerts continued: “… Surely you are not saying that the CO2 rise in the last ~ 100 years is the RESULT of warming?!
My response: Why not? Natural processes have caused warm and cold cycles (multi-decadal shifts, century periods, ice age/interglacial cycles, ice epochs, ice eras) over every meaningful time period for climate. Why, suddenly, must those natural processes be replaced with a theory that has yet to be demonstrated? On what basis do we reject the likelihood that multi-decadal warming trends of the past century are not perfectly normal today? And on what basis do we reject the strong likelihood that we are experiencing a modern warming period that is just as natural as well recorded past warming periods?
I wrote: ” … two continental locations at the same latitude …”
tjfolkerts replied: “Phoenix and Atlanta fit the bill pretty well… Yes, Phoenix is hotter. However …
1) Phoenix is significantly less cloudy, allowing in more solar energy, which by itself should make phoenix (and desert locations in general) warmer than Atlanta (or similar locations).”
My response: So changes in surface temperatures are strongly influenced by changes in cloud cover. This is key to the Svensmark theory and should provide ample rationale for thoroughly examining this climate influence. Yet Svensmark is ridiculed by “the usual suspects” … but I digress from the point.
tfjolkerts continues: “2) The difference between high and low is greater in Phoenix. The lack of GHGs mean more effective cooling at night.”
My response: The lack of clouds might just dominate the difference at night. My point was that the “climate” in these two areas have a striking difference in the dominate “greenhouse” gas, water vapor, yet the greater heat is observed where that greenhouse gas is extremely low.
I wrote: “what prevents this cyclic process from continuously warming Earth’s surface in a runaway process?”
tjfolkerts replied: “… The infinite series converges, with a finite warming from added GHGs. There are other sorts of feedbacks that could magnify the effect… but even these can’t lead to temperatures spiraling upward toward infinity.”
My response: I’d love to pursue this point further, but cannot as my time and travel resources are limited. However, for the sake of discussion, let’s assume this claim is accurate and a cooler atmosphere can, somehow make Earth’s surface WARMER (as opposed to reducing the rate of cooling). If that is the case, then an upper limit can be computed to just how warm Earth can get from this claimed greenhouse effect. What is that limit? How does it compare with past climate, in particular, when Earth is not within an Ice Epoch of and Ice Era and global temperatures average roughly 10 degrees C (18 degrees F) higher than at present (e.g., Earth’s climate when dinosaurs reigned for about 200 million years)? Over the past 500-600 million years, the correlation between atmosphere CO2 and climate is sufficiently poor to discredit a causative link and should suggest we look elsewhere to understand those factors that are responsible for Earth’s surface temperature.
I wrote: “… this miraculously clever “greenhouse effect” that knows just how much warmth is needed? … Pierre R. Latour, PhD, has given this question serious consideration.”
tjfolkerts reply: “This seems an oddly backwards way of thinking…”
My response: Why is it “oddly backwards” to suspect a “back of the envelope” calculation based on limited factors to compute a disparity between observed global temperature (a hard enough measurement to pin down) and what that calculation implies are the only possible sources for global temperature other than the misnamed “greenhouse effect”? If there is anything oddly backward, it is the quick acceptance of a theory that strains credibility on the basis of calculations of what “should be” rooted in assumptions and a background of immature climate science knowledge. Climate and climate change are extremely complex and dependent upon so many factors that are poorly understood. Even if we could accurately model the Earth’s climate dynamics, collecting sufficient data to feed the model would be extremely costly and difficult. Current models assume the GHE Theory and yet fail miserably at predicting current climate from past conditions (See article at WUWT quoting Freeman Dyson http://wattsupwiththat.com/2013/04/05/freeman-dyson-speaks-out-about-climate-science-and-fudge/)
tjfolkerts continued: “The GHGs do provide some warming via backradiation (or ‘reduction of cooling’ if you want to be picky).”
My response: But you assume the greenhouse effect to prove the greenhouse effect! You claim the temperature difference can be satisfied by a greenhouse effect, and use the assumed greenhouse effect to prove the difference is the result of a greenhouse effect. This is not science, it is science fiction. The semantics should not be treated so cavalierly. It is not being “picky” to be accurate and clear. There is a distinct difference between a “reduction in cooling” and “warming” – the former reduces heat loss while the latter adds heat. This is the very crux of the contentious issue. To suggest that a reduction in the rate of cooling is the same as warming is seriously misleading.
jffolkerts continues: “Fortunately the theory does give the right ballpark for surface temperatures, whereas a nonGHG atmosphere cannot come even close to the right temperatures.”
Latour’s excellent article wherein he does exactly what you claim cannot be done uses first principles of sound physics. He does not have to rely upon unproven THEORY (greenhouse effect WARMING of Earth’s surface) that depends upon wholly unrealistic assumptions about Earth’s characteristics (flat Earth models, blackbodies, etc.).
tjfolkerts continues: “Unfortunately, his ‘serious consideration’ is good occasionally, but overall it is seriously lacking.”
My response: Perhaps you’d like to explain where Latour is “seriously lacking” – a pretty hefty accusation in the absence of any explanation.
tjfolkerts end with: “Clearly we are not going to resolve these issues here. I just wanted to provide some food for thought to show that your objects are not ‘fatal’ to climate science.”
My response: Again, I appreciate the civility of tjfolkerts in this exchange. I’ve tried to respond in kind. And I agree that we are not likely to come to see this issue the same based on this kind of exchange. However, I strongly believe that if commenters are civil and respect differing views (the essence of real scientific inquiry), then we can all learn from each other and move the science forward. The points raised by tjfolkerts are fair and certainly reasonable from the perspective taken – and while our civility doesn’t make either of us correct, it makes the exchange worthwhile.
“And you still have not explained why a desert is hotter than a rainforest within the concept of the GHE.”
Rainforests tend to have a higher average temperature. Deserts can get cooler at night.
Death Valley highest daytime temperature: “134 °F (57 °C) on July 10, 1913, at Furnace Creek, which is currently the hottest temperature ever recorded.”….
“The summer of 1917 had 52 days where temperature reached 120 °F (49 °C) or above with 43 of them consecutive.” …
“The lowest temperature recorded at Greenland Ranch was 15 °F (−9 °C) in January 1913.”
“The mean annual temperature for Death Valley (Furnace Creek Weather Station) is 77.2 °F (25.1 °C) with an average high in January of around 67 °F (19 °C) and 116 °F (47 °C) in July.
http://en.wikipedia.org/wiki/Death_Valley
Generally, tropical rainforest:
“The average yearly temperature is approximately 80 °F (26 °C) but the temperature can range from 68 °F (20 °C) to 93 °F (34 °C).”
http://wiki.answers.com/Q/What_is_the_average_yearly_tropical_rain_forest_temperature
So hottest place on planet has average yearly temperature of 77.2 °F and generally rainforest have about average of 80 °F.
Or it tends to be much warmer at night in tropical paradises.
“What is the coldest temperature recorded in Singapore?
The lowest minimum temperature ever recorded in the month of December is 20.6 deg C ( on 2 Dec 1964), while the lowest temperature ever recorded (since record began in 1929) is 19.4 deg C (on 31 Jan 1934).
Cool weather over Singapore are caused by the following conditions :
i ) periods of cloudy to overcast weather accompanied by rain which blocks out the heat from the sun
ii ) season and prevailing wind
Singapore’s average annual rainfall is 2357.8 mm. ”
http://www.weather.gov.sg/wip/web/home/faq
“Singapore is 1 degree north of the equator. Singapore’s climate is classified as tropical rainforest climate (Köppen climate classification Af), with no true distinct seasons. Owing to its geographical location and maritime exposure, its climate is characterized by uniform temperature and pressure, high humidity and abundant rainfall. The average annual rainfall is around 2,340 mm (92.1 in). The highest 24-hour rainfall figures ever recorded in history was 512 mm (20.2 in) (1978), 467 mm (18.4 in) (1969) and 366 mm (14.4 in) (19 December 2006). The temperature hovers around a diurnal range of a minimum of 23 °C (73.4 °F) and a maximum of 32 °C (89.6 °F). May is the hottest month of the year in Singapore, followed by April. This is due to light winds and strong sunshine during those months. The highest recorded temperature is 36.0 °C (96.8 °F) on 26 March 1998. The lowest recorded temperature is 19.4 °C (66.9 °F) on 31 January 1934. Temperature often goes above 33.5 °C (92.3 °F) and can reach 35 °C (95 °F) at times.
Relative humidity has a diurnal range in the high 90s in the early morning to around 60% in the mid-afternoon, but does go below 50% at times.”
http://en.wikipedia.org/wiki/Geography_of_Singapore
So in tropical rainforests you can run around without any clothes, but without clothes in deserts, you could freeze.
Gary,
Please. Science of Dumb? Er… I mean “Doom”? I visited that site. I argued with him under the name “Jonathan” in March of this year. Those equations are simple heat transfer equations which you will find in any thermo or physics textbook. They do not invalidate the 2nd Law. I challenged Mr. Dumb to find me a textbook problem example which indicates a cooler body warming up a warmer body. Not just an equation, but a worked up problem with real numbers. He could not provide one. There are none.
george e. smith says:
Bryan, I am going to assume that English is NOT your native language. You clearly didn’t read what I wrote; to whit;
“””””….. but the terminal Voltage increases, just as if the internal resistance has increased (it has)……”””””
Doesn’t say one word about increasing the Temperature of a semiconductor.
I believe I said that the terminal VOLTAGE increases.
I believe I said that the CURRENT flowing stays constant.
I believe that Voltage times current equals power.
I believe I said the applied power increases.
I believe if you put more power into ANYTHING, it will get hotter.
I believe that Voltage divided by current is (one measure of) RESISTANCE. (not necessarily Ohmic).
I believe that a higher VOLTAGE divided by a constant CURRENT implies a higher RESISTANCE..
And finally, I believe that if you made your first LED (light emitting diode) prior to June 1966, that you probably do know more about LEDs than I do.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
George if something gets hotter then its temperature has increased.
You say;
“just as if the internal resistance has increased (it has)…”
“I believe if you put more power into ANYTHING, it will get hotter.”
My simple observation is that since the LED is made from semicondor material then in this case its resistance will go down.
This cannot be squared with your statement above.
Read the following article or any similar source on the topic.
http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity
Typo
semicondor material should read semiconductor material
gbaikie says: “I don’t think if you made Mars the surface lamp soot black that the day time surface
temperature would much warmer”
As a ballpark figure, Mars now absorbs ~ 75% of the incoming solar energy. Making it perfectly black would change that to 100%. Since temperature is proportional to P^0.25 and power has gone up by a factor of ~ 100/75, the temperature would go up by a factor of ~ 100/75^0.25 = ~ 7.5 %. So if the average is ~ 220 K now, it could increase by ~ 16 K. (Again, these are rough estimates that ignore lots of details that could change the results a bit.)
gbaikie says: “I think methane may warm it a bit more than non-GHGs.”
Mole for mole, adding GHGs has more impact than adding non-GHGs, so I agree that adding a given amount of methane (or CO2) would have more impact than the same amount of N2 (or O2).
The basic argument is related to the lapse rate. Adding more N2 would raise the CO2 on average. Since the CO2 is now radiating from a higher altitude where it will be cooler, it will radiate less, so the ground will have to radiate more to compensate. (There are even plenty of people who incorrectly argue that mass alone causes warming, even without the effect of the GHGS.)
More N2 would have a minimal impact on the solar energy reaching the surface. This would create a minimal cooling effect, which would be overpowered by the lapse-rate warming effect.
tjfolkerts says:
July 20, 2013 at 7:51 am
“Since the CO2 is now radiating from a higher altitude where it will be cooler, it will radiate less, so the ground will have to radiate more to compensate.”
You are confusing the behavious of a blackbody, which radiates less when it is cooler, with the behaviour of a gas molecule, which will only radiate on its spectral lines. The entire argument of CO2AGW is based around the absorption and re-emission of photons of exactly those frequencies; and as I never tire to assert, Kirchhoff’s Law states that in local thermal equilibrium, thermalization equals dethermalization; so the photons that the CO2 molecules high up in the atmosphere absorb and re-emit, and which mostly come from lower atmosphere layers, are already of a frequency of those spectral lines and the temperature of the CO2 molecule that captures them plays no rolw at all in the process.
“baikie says: “I don’t think if you made Mars the surface lamp soot black that the day time surface
temperature would much warmer”
As a ballpark figure, Mars now absorbs ~ 75% of the incoming solar energy. Making it perfectly black would change that to 100%. Since temperature is proportional to P^0.25 and power has gone up by a factor of ~ 100/75, the temperature would go up by a factor of ~ 100/75^0.25 = ~ 7.5 %. So if the average is ~ 220 K now, it could increase by ~ 16 K. (Again, these are rough estimates that ignore lots of details that could change the results a bit.) ”
What could be done is take dry brownish red sand and carbon and expose them to sunlight
on Earth which is around 500 to 600 watts per square meter. And measure their temperature.
On Mars the ground in sunlight near noon get about 80 F.
What I did, was I have some brownish sand [probably more reflective as compared to Mars regolith].
And took 3 barbecue briquets and crushed them into small pieces. And put them on table outside.
each sample about 6 by 6″ area and 1/8th to 1/4″ deep.
Right now it’s cloudy [looks like it might even rain- unusual weather for southern calif in summer, but cloudy in morning is normal and probably burn off. Now 8:30 am. Maybe direct sun will appear by 10 or 11 am. And they are now 68 F.
So if and when sand is 80 F [26.6 C] what will the temperature of crushed briquets be?
I think there more advantage of briquets warming quicker, due to it being black and due to lower specific heat [plus sand is a bit damp]. Plus if sun come out [unless it’s as early as around 10 am] I will have more than 600 watts per square meter.
Despite this I don’t think there will a temperature difference more than 5 C.
And air temperature has been reaching about 80 F, so the effect of air should be minor, unless surface temperature gets above 90 F [I forget it check once gets to 80 F].
Different color painted cars:
http://www.tom-morrow-land.com/tests/cartemp/
It’s already 3 C difference. Sand [still damp] 20 C and crushed briquets 23 C.
And still cloudy. 8:55 am
“Still, your pseudo “the 2nd Law” can be valid, but you need to prove it, what no one managed to do.”
It is you, greg, with the pseudo 2nd Law. The “net” concept is there. It is reinforced in the modern statistical mechanics statement of the 2nd Law in terms of entropy and probabilities. It takes almost a willful misreading to say that no energy can move from colder to warmer.
The 2nd Law is fundamentally about probabilities. There is a chance that an atom/molecule/solid will emit a photon. The probability increases if the atom/molecule/solid has more energy. A hotter atom/molecule/solid has more energy on average. So on average, more photons with higher energy will move from a hot atom to a cool atom, than from a cool atom to a hot atom. (The same general idea applies to collisions & conduction).
Energy moves randomly from any atom to any other atom. The odds just favor the transfers from warmer to cooler.
Hope this helps clarify;
http://drtimball.com/2013/a-basic-and-powerful-analysis-of-greenhouse-effect-fallacies/
gbaikie,
Experiments are always a good place to start. 🙂
I was calculating a ‘global average’ change. The difference could be greater during the day due to sunlight. On the other hand, there would be local cooling effects from conduction/convection, which would dampen any differences. So it is tough to be too precise predicting the changes for small patches like that.
Dirk says July 20, 2013 at 7:57 am:
” You are confusing the behavious of a blackbody, which radiates less when it is cooler, with the behaviour of a gas molecule, which will only radiate on its spectral lines.”</em.
Let me try to be more clear about the physics.
The blackbody curve sets the maximum possible thermal radiation. This curve gets smaller and shifts to longer wavelengths as the temperature drops.
The specific material determines how close to that theoretical maximum will actually be created by a 'glowing object'. A material like water with a high emissivity (~ 0.96) will emit a spectrum quite close to the theoretical blackbody curve. A material like polished aluminum with a low emissivity (~ 0.05) will hardly emit any thermal iR.
CO2 has bands where it emits well (eg near 15 um) and other bands where it emits poorly. In the bands where it emits well, it will emit about like a blackbody. in the bands where it emits poorly, it will hardly emit any thermal radiation. (Put another way, the emissivity varies dramatically depending on the wavelength you are talking about). But this radiation is still limited by the "envelop" of the blackbody curve.
Combine all this, and warm CO2 does indeed emit more thermal iR than cool CO2.
“Kirchhoff’s Law states that in local thermal equilibrium, thermalization equals dethermalization”
You are missing one key idea, which is that the atmosphere will (almost) always be cooler as you go higher. If the CO2 in a region absorbs some specific wavelength with 90% efficiency, it will also emit with 90% efficiency (Kirchhoff’s Law). However, as thermal energy is working its way up through the atmosphere, CO2 at any given level would be efficiently absorbing the “hot bright IR” from below and efficiently emitting “cold, dim IR” upward in its place.
So yes, the CO2 molecules still emit 15 um photons no matter what the temperature, but the cooler CO2 molecules emit fewer of them. So CO2 DOES have an impact on the spectrum.
Check out MODTRAN: http://forecast.uchicago.edu/Projects/modtran.html
Try looking down from various altitudes. (Maybe remove everything but CO2 to make things simpler). Near the surface (say 1 km up) the CO2 absorbs the surface IR, but replaces it with similar IR since it is a similar temperature. Go to 2km or 5 km or 20 km. The IR in the CO2 bands will keep decreasing as the temperature keeps decreasing.
Maybe (Wicki’s definition) of Fick’s Law is of some help here:
Fick’s first law relates the diffusive flux to the concentration under the assumption of steady state. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative).
Fick’s Law is already from 1855. You don’t see anything in that law that is called net diffusive flux, although most here will know that a lot of molecules/ions or whatever will diffuse from the lower concentration towards the higher concentration as all such movements are random. But the movements from higher concentrations to lower outnumber the opposite movements, so that the net flux is in from high to low.
Something similar is happening with radiation exchanges between a warmer and a colder object. There is radiation going from a colder object to a warmer one, which is absorbed there, but the radiation of the warmer one outnumbers that of the colder object, so that the net heat flux is from warm to cold…
tjfolkerts says:
July 20, 2013 at 11:11 am
You are missing DirkH’s point. We don’t care about emissions which occur due to ambient temperature. Those would occur in any case, with or without additional CO2. We care specifically about emissions which occur as remission of emissions originating from the Earth’s surface, roughly half of which return to that surface.
You are putting the cart before the horse. Increasing the height of the CO2 in the atmosphere does not cause greater heating. Greater temperature increases the average height of the CO2 in the atmosphere. It cannot be both, because that would constitute a runaway positive feedback loop. Temperatures go up, pushing the CO2 higher, which raises temperature, which pushes the CO2 higher, and so on ad infinitum. Pretty soon, the CO2 would boil off into space.
Anthony–You are correct to allow the “slaxxrs” a place here.
The point is–the science is NOT settled. Allowing Slaxxers to comment here verifies your search for the truth.
True, they may be after their own “Nobel Prize”, but the truth will always out.
Keep up the great effort.
We can solve this whole problem if we stop calling it “warming” and instead call it “slower cooling”.
Therefore, it is not getting peak hotter, to any material degree, it is just getting cooler slower enough to raise the average temperature over time.
We can quibble that the instaneous cooling is also slowed, thereby raising the instaneous peak temperature in these experimental situations; but the main effect of the terribly named greenhouse effect is a reduction in the rate of cooling, and therefore the higher average temperature over time, because of IR reflectivity.
I don’t think human CO2 is a big deal, but this argument about IR heating the surface is inane; and a change from saying it heats the surface,to saying it slows the rate of cooling of the surface and lower air masses, might just get the stupid semantical nomenclature arguments out of the way.
tjfolkerts says:
July 20, 2013 at 9:07 am
““Still, your pseudo “the 2nd Law” can be valid, but you need to prove it, what no one managed to do.”
It is you, greg, with the pseudo 2nd Law. The “net” concept is there. It is reinforced in the modern statistical mechanics statement of the 2nd Law in terms of entropy and probabilities. It takes almost a willful misreading to say that no energy can move from colder to warmer.”
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Again, there is no “net”-word in the historical statements of the 2nd Law. Nor can this “net” thing be derived from those historical statements. You and others can claim whatever “net”-concept you like, but no one has proven it correct. You simply misinterpret the 2nd Law by inserting something else into it. As I said, claim whatever you want but do not call it “the 2nd Law”, because it is not.
As for “cold can warm hot”, I have already demonstrated above that this assumption inevitably leads to an absurd result, which proves this assumption false, no reference to the (real) 2nd Law being necessary. Your “greenhouse effect” is physically impossible.
Marc says:
July 20, 2013 at 1:18 pm
Go Marc…..
Bart, I seem to be missing your point, too. All thermal radiation is “emissions which occur due to ambient temperature”. That is the ONLY thing we should be concerned about!
There is a fundamental misunderstanding when you say “emissions which occur as remission of emissions originating from the Earth’s surface”. CO2 emits based on its local temperature ie based on its own current energy. The constant jostling of the molecules in the atmosphere means that the “original source” of any energy is completely lost. Since the atmosphere is (almost) always cooler higher up, the net flow of thermal photons is always upward. Talking about “re-emission or “reflection” of the ground’s IR is a common simplification that many people use, but it is not a good way to really think about the situation when getting into the physics involved.
“You are putting the cart before the horse. Increasing the height of the CO2 in the atmosphere does not cause greater heating. Greater temperature increases the average height of the CO2 in the atmosphere.”
Again, I think you misunderstand what I was saying. We could raise the entire atmosphere by heating it, but that is not what I was discussing.
For the emissions to space, only the “top layer” of CO2 matters. Infrared cameras tuned to 15 um aimed at the earth from outer space only see photons that come from high in the atmosphere. Of course there is not a clearly delineated “top layer” with sharp boundaries, but think about the top few grams of CO2 in any square meter. That “top layer” is a wide slice somewhere around 15 km up with current conditions. Suppose we double the CO2. That slice at 15 km up will now have twice as much CO2. That means the true “top slice” is now the top of that slice … maybe 16 km up. Well, 16 km up the air will be ~ 6-10 K cooler, so the CO2 in the “new top layer” will emit less energy to space than the “old top layer” did.
Same basic idea applies if more N2 is added. The N2 will “dilute” the entire atmosphere, raising the top few grams of CO2.
In either case, the top is cooler and emits less energy to space — without changing the amount of solar energy coming in. The system has to re-adjust until balance is restored. The simplest re-adjustment would be for the entire system to warm slightly from top to bottom (although other changes like more clouds reflecting more sunlight could also occur).
Yep, Marc.
This topic too often gets muddled in semantics rather than physics. Either the discussion has to be very technical in the use of word like “heat” (in which case you lose the people how don’t have a degree in physics), or you can be colloquial (in which case you take liberties with precision).
Greg is case in point. He says that I am saying “cold can warm hot” and then attacks the colloquialism rather than the physics. In fact I am saying something more like ” ‘hot’ and ‘cold’ fight to determine the temperature of the ‘warm’ intermediary. If you weaken ‘cold” by making it only ‘cool’ instead of ‘cold’, then ‘warm’ will get warmer.” Seems pretty intuitive and obvious to me when stated in a more correct way.
The cool object (in conjunction with an active heater) helps determine the temperature of the warmer object — its as simple as that. The cool insulation of your house (in conjunction with the hot furnace) helps keep the house warm (compared to having the walls thermally connected to even colder air outside). The cool atmosphere (in conjunction with the hot sun) helps keep the earth’s surface warm (compared to having the surface thermally connected to even colder outer space).
Greg House says:
July 20, 2013 at 1:30 pm
Again, there is no “net”-word in the historical statements of the 2nd Law. Nor can this “net” thing be derived from those historical statements.
Greg, there is no “net”-word in the historical statements in Fick’s Law of diffusion of 1855. Despite that, it is proven that all the molecules/ions move in all directions and even some move from lower concentrations to higher concentrations. Fick’s Law only says that in average more molecules/ions move from the higher concentration to the lower one than reverse.
The 2nd Law of heat transfer doesn’t count for individual packages of radiation energy, fotons, which go in all directions and even some are emitted from a colder object and are absorbed by a warmer one. All what the 2nd Law says is that in average more radiation energy is transferred from a warmer to a colder object than reverse.
Ferdinand Engelbeen says:
July 20, 2013 at 2:39 pm
“All what the 2nd Law says is that in average more radiation energy is transferred from a warmer to a colder object than reverse.”
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This is not true, the 2nd Law says nothing about “average”, exactly like it says nothing about “net”.
Again, the assumption “cold warms hot” leads to an absurd result and is therefore false, see my demonstration above.
Marc says:
July 20, 2013 at 1:18 pm
“We can solve this whole problem if we stop calling it “warming” and instead call it “slower cooling”.”
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No, you can not save the “greenhouse effect” this way. “Slowing cooling by back radiation”-effect would mean an alleged energy supply that causes a warming of an object at initially stable temperature (with an absurd result, see above) and an increasing warming of an object that has already been in the state of warming. It is still the same impossible “back radiation warming effect” regardless of how you call it.