Visualizing the "Greenhouse Effect" – Atmospheric Windows

Ira,
Are there any experiments which detect the incoming re-emitted radiation from the atmosphere? Did a quick search and only came up with models. It seems like we should be able to detect the radiation coming back at us from the atmosphere if this model is valid.

Can you please give me the references for CO2 IR re-emittance

Finally someone has addressed the “atmospheric window” effect. There is a lot more to be said, but for now, “it’s about time”.

From the looks of that first chart, ~100% of 7μ and 15μ radiation gets absorbed by the atmosphere on the way back to space, mainly by H20 and CO2. Maybe a tiny trickle bounces its way from molecule to molecule and makes it to space.
If that’s so, then doubling or even tripling the values of H2O in our atmosphere should have no effect on absorbtion. You can’t absorb more than 100% of the radiation, right?

RJ,
I would guess that the vast majority of energy leaves earth by radiation. It has recently been discovered that our atmosphere is being continuously shed by the solar wind, and replenished by volcanism. This would be the only vehicle for convection that I can think of, and no idea if it is significant.

Inspection of the infrared absorption windows for CO2 and H2O shows the much greater greenhouse effect of H2O. Yet I’ve often heard that the H2O only appears in the computer models as being forced by CO2, and therefore it doesn’t matter that H2O is a far more effective greenhouse gas than CO2. (People who want to regulate CO2 generation say this) My opinion is that the sensitivity to CO2 is weak, and it is an artifact of the written models that show CO2 effects predominating over H2O. Furthermore, because H2O changes from gas to liquid and back again, the H2O may even have a negative, regulating influence on the CO2 contribution to the greenhouse effect. Certainly the density driven convection caused by cloud formation and evaporation has a strong stirring effect that carries heat aloft. (A key difference between Earth and Venus is Venus’ lack of winds and vertical convection that carry heat upward)
I would like to see a discussion of these issues, as I think this is key to the AGW enthusiast/ skeptic differences of opinion.
Thanks,
Dan

etudiant says:
February 28, 2011 at 2:18 pm
Relative humidity in the upper atmosphere (300mb level) has fallen from around 55% in 1950 to about 45% now.
Should this not have a material impact on the greenhouse effect?
It is hard to get concerned when such substantial changes don’t even warrant discussion, much less explanation. Or is there some obvious offset that makes this moot?
——–
Sadly Dr. Miskolczi’s paper and it’s implications are rarely mentioned here, for that aspect of which you speak is probably why increased co2 has had little effect in reality (or it least it hasn’t had any measureable effect in the last 60 years). The slight warming came from some other reason and that is the real mystery, what other reason.

jknapp; it is a misundertanding on your part. The wavelength specific nature of say CO2 or H2O is a function of the absorption modes of those molecules, which relate to specific mechanical resonances of the molecules themselves.
BUT most of those excited molecules DO NOT get a chance to re-radiate, that photon, and return to the unexcited state. The time interval between molecular colliwsions is a few nanoseconds; but the lifetimes of the excited states, can be microseconds to milliseconds; so the energy is lost in collisions, before the molecule gets a chance to re-radiate. That thermalization heats the whole atmosphere; the N2, the O2, the Ar, and anything else; and it is that mixture of gases, at somer average temperature in the 250-300 K range, that is the source of the atmospehric emitted thermal continuum spectrum, that is not related to specific molecular energy levels, but only to the Temperature of the gases; whcih determines the dynamics of the collisions, and the resulting chaotic accelerations of the colliding molecules, and the electric charges they contain.
So the atmosphere does radiate a black body like thermal spectrum, and the presence of the gHG molecules simply means that there will be bands of that continuum emission, that are also captured by the GHG molecules, as well as the emissions from the surface.
The only function of the GHG molecules is to heat the atmospheric gases; along with all the other mechanisms that are heating it. After that, the GHG molecules serve no function in the climate process whatsoever.

In your animated diagram what happens to the downward re-emitted 7μ radiation when it reaches the earth surface? I believe that what happens is that it may emitted again as 7μ IR radiation, or at a longer wavelength such as a photon in the 10μ band. In the former case it will have a high probability that it will be absorbed and downward emitted again, and in the latter case it will be lost to space.
Thus the 7μ band sees not an equilibrium of up and down radiation flux, but a continuous stream of loss to 10μ. This would cause more energy to be lost than in your model.

This graph, about the atmospheric absorption, is from the 1970’s. Could anyone provide a recent one? Just to compare things.
Thanks in advance.

etudiant said:

Relative humidity in the upper atmosphere (300mb level) has fallen from around 55% in 1950 to about 45% now.

Can you provide a reference for that?

Thanks for intresting post. Have you considered that Quiet Sun makes atmosphere to shrink and as we know from sound waves, low frequency sound waves go easier through thinner wall as well shorter waves starting to go through if wall is thinner. I believe that IR acts same way. Is there any measuremet of IR behavior between situations when atmosphere is puffed up or shrinked down? Collapse of thermosphere can make diffrencies to athmosphere’s density at least down to 30 km altitude. I believe, it can have measurable effects to atmospheric temperature.

If absorption of the re-radiated energy by water vapour is logarithmic akin to that of CO2, and the concentration of water vapour in the atmosphere is genrally already several orders of magnitude higher than CO2, how can an increase in absolute humidity have any more than a miniscule effect? It seems the models rely on this increased humidity feedback to amplify the small incremental warming from CO2 to a significant several degrees C. As we know from the characteristics of CO2 the bulk of the so called “damage” is done within the first 100ppm. Is water vapour any different?

Another little thought visualization for CO2 in the atmosphere.
Let a backyard swimming pool represent the atmosphere.
Let the air above it represent outer space.
A black colored ball bobbing in the water represents CO2.
The black ball is calculated by size in relation to the pool for its appropriate ratio as per CO2 in the atmosphere.
The sun comes up and warms the water, and the black ball is a heat sink due to its color. The heat absorbing ability of the black ball represents CO2’s greenhouse effect.
At the end of the day, heat absorbed by the water is released to the air, representing atmospheric heat released to space. Heat absorbed by the ball is released to the water representing CO2’s heat retention/reflection in the atmosphere.
How much is that tiny ball bobbing in the pool going to maintain the pool temperature?…. I do not think it is even measurable. The dynamics of the entire pool are too great to overcome by this little ball and reach a temperature equilibrium regardless of the little ball’s efforts.
A black ball representing the man made CO2 would be even more insignificant.
CO2 is treated in AGW articles like it is a nuclear heat source of magic abilities to retain/conserve heat. I don’t buy it.
I do not believe that CO2 in tiny amounts can heat the earth as claimed. Mars is almost 100% CO2 and it’s still too cold for us to live there… where is the runaway greenhouse effect on Mars?
A simple visualization like this displays the obvious that it is physically impossible for CO2 to have any major effect on earth’s temperatures as claimed.

Nice visual aid. I’m not a scientist, however I’ve had extensive experience operating in jungle and desert environments. My direct observations have been that in the jungle, where humidity is very high, it stays hot when the sun goes down. Almost the whole night through. In the desert, where humidity is very low, it cools down rapidly when the sun goes down. At altitude it can get damn cold. Now I’m making a WAG here, but I assume that the atmospheric CO2 level is the same in both environments. Therefore, it is the humidity, atmospheric water vapor, that is the moderating element and CO2 does nothing. So in order for CO2 to contribute to global warming, it requires the sun. And I am given to understand that radiation from the sun only acts on water vapor and CO2. The other atmospheric gases, mostly nitrogen and oxygen, do not do anything, they absorb no radiation of any wavelength nor reflect ant radiation of any wavelength. Not being a scientist, for the sake of argument, I’ll accept that. But what I have a very hard time accepting is how a trace gas, CO2, can have any effect on anything.

Solar input (in the sense of the amount of energy being received at the top of the atmosphere from the sun) may be costant although there may yet be processes that we have yet to understand.
However, the mere fact that the energy from the sun is constant does not mean that the amount of energy received at ground level has remained constant. There only needs to be slight variations in the amount of clouds (their area, shape, reflectivity) to result in changes to the amount of energy received by the oceans and the land. A change in the pattern of the clouds of just 1 or 2% could account for all the observed warming. We have no real historical data of cloudiness.
The point raised by etudiant February 28, 2011 at 2:18 pm is a good point. I would like to hear some more on this and the effect that this ought from a theoretical point of view had on warming/cooling observed at the surface..
Measuring the temperature of the oceans is probably the best metric for assessing whether there is any warming. This is becuase the oceans account for about 70% of the surface area of the globe and they contain (ignoring the core) approx 99% of the stored global energy. Further, a change in temperature in the oceans can be converted to joules and thus the heat content is know. Land based air temperature record does not measure energy since it does not also include data for humidity/moisture content.
i disagree that measuring ocean temperature can be used to assess sensitivity. In my opinion, measuring the heat content of the oceans cannot necessarily be used to assess sensitivity since a slight change in the amount of cloudiness has a significant impact on the amout of solar radiation being received by the oceans. Unless we accurately know the total amount of clouds and their pattern, we will not be able to rule that out as the source of any observed warming (or cooling).

“Most Sunlight is in the visible band from 0.38μ (which we see as violet) to 0.76μ (which we see as red), which is why our eyes evolved to be sensitive in that range.”
======================================================
I probably would have come away with a more complete view of your posting had you not included this little statement. I read through your post, and most of it, I agree with.
But, towards the mentioned statement………….. That’s beautiful, you’ve managed to refute Newton without expressing how or why. But, gleaning what I can from this statement, our eyes evolved to seeing something we couldn’t otherwise see…………..because of the entire specie’s collective inherent knowledge? And thank God……errrr, uhmm…..thank Gaia…..errr…..thank evolution for giving that to us, else we’d be navigating in a manner such as bats!

Fred
“I would guess that the vast majority of energy leaves earth by radiation”.
It would leave the outer atmosphere by radiation. But Charles R Anderson in STSD Ch 20. In the denser, lower altitude atmosphere, most energy transfer is due to gas molecule collision etc.
I don’t know but it seems even the experts do not agree on this.
Most accept the GHGT (even sceptics) but the more I read on this topic the more I’m of the view that the entire GHG theory is flawed. But I’m not an expert.

Another thought…
Suppose I bought a container of CO2 for carbonated beverages and boosted the CO2ppm from 390 to 1000ppm in my apartment air.
Will the winter sunshine boost my apartment temperature by say 10 degrees F due to the greenhouse effect of the CO2 ? Doubtful…
I’d save a lot on my heating bill if that would work… if it really did work, we’d all be doing it.

It is the first time I’ve seen an explanation where the energy represented by the specific frequencies absorbed by GHG molecules are transferred to non-GHGs through collision (and then reemitted by the non-GHGs in the atmospheric windows – almost everyone believes the non-GHGs absorb and emit no IR radiation at all – some bad textbooks mis-educated everyone somewhere along the line).
But then, to show this has a real greenhouse effect (an extra 150 watts/m2 at the surface), the numbers have to be crunched taking into account the time lag between absorption and effective emission to space.
The 10 um atmospheric window actually emits at a higher energy level than it should according to Earth’s temperature alone.
Second, if it was a simple process of 1 CO2 molecule absorbs a 15 um photon and then passes that on to 1 N2 molecule which then promptly emits that to space in the atmospheric window at 10 um, there be no greenhouse effect at all.
The entire process would only take 0.001 seconds for ALL the photons to escape to space. Once the sun sets, the atmospheric temperature should fall to -220C within a second.
But the average time the energy represented by a solar photon spends in the Earth system before it is lost to space is 43 hours. It spends time in 5 billion different molecules before it escapes to space on average.
There is much much more going on here which I would love to see explained to my satisfaction.

For Leif Svaalgard to ruminate upon..
http://www.halesowenweather.co.uk/cet_sunshine.htm

Ira, I like the description overall but I do not like the Wiki graph of the outgoing infrared. It is technically correct in that it shows the likelihood of a photon of a particular wavelength being emitted by the earth and then passing through the atmosphere without being absorbed. However it might give the impression that it is the spectrum radiated into space. In practice the radiation into space is pretty much the black body spectrum you would expect for a body at about 290K with reductions at particular wavelengths particularly between 5 and 8 micron and between 14 and 18 micron as you describe in your text. Photons of these wavelengths can only be radiated into space by water and CO2 molecules at very high altitude since emissions lower down are absorbed. The lower temperatures at these altitudes acount for the reduced emissions.
George E Smith. I do not think I agree with your last point assuming I understand it properly. You state “The only function of the GHG molecules is to heat the atmospheric gases; along with all the other mechanisms that are heating it. After that, the GHG molecules serve no function in the climate process whatsoever”
As I have just explained CO2 and H20 are the main sources of radiation into space from the troposphere and indeed CO2 is the main source of radiation from the the stratosphere which is heated directly by the absorption of UV from the sun mainly by ozone. As I read it you seem to imply that the greenhouse molecules pass all their energy to the O2 and N2 molecules which then radiate into space. However they can’t since there is a law which says that a bad absorber cannot be a good radiator. In reality the energy is partitioned amongst all the molecules but the CO2 and H20 molecules radiate into space and cool the upper troposphere and tropopause. So the greenhouse gasses warm and they cool as well. That is the nature of thermodynamics.
Further to this point there have been several comments to the effect that you cannot have energy passing from a cooler to a warmer body. This is not true. The rule is that you cannot have a net energy transfer in this direction but there is always energy being radiated from any body above absolute zero. So greenhouse molecules do warm the earth. It is just that they are being warmed by the earth at a greater rate. So the nett flow is upwards.

Ira,
” The ~7μ and ~15μ generated by the heating of the air also emerge from the top or bottom of the Atmosphere, but there are fewer of them because they keep getting absorbed and re-emitted, each time with some transfered to the central ~10μ portion of the longwave band.”
Could you give more details as to what shifts the energy into the ~10μ window. Is this due to net out from the surface of the absorbed back radiation or are there other effects??

George E. Smith says:
February 28, 2011 at 3:23 pm
The only function of the GHG molecules is to heat the atmospheric gases; along with all the other mechanisms that are heating it. After that, the GHG molecules serve no function in the climate process whatsoever.
—–
George, are you positive of including the word “only” in your statement and not “one of”. I read from those words that you don’t think thermalization can run in reverse the way the equatuion reads with symmetry. Like when the atmosphere is warmer than it should be compared to the surface and at dusk or night. I have always viewed GHGs can either heat or cool depending on the exact conditions. Any clarification?

Bill
almost everyone believes the non-GHGs absorb and emit no IR radiation at all
Bad textbooks. It seems that way. Because otherwise how would say Nitrogen release energy. Some would be by convection by surely not all. Otherwise it would have to collide with water vapour or CO2. Which might not happen. And then what as it rises higher and higher.

Katherine 4:26
So, when the Earth warms, it radiates less longwave radiation in the bands absorbed by CO2 and when it cools, it radiates more longwave radiation in the bands absorbed by CO2?
I think you are right except that the longwave radiation that would subsequently move beyond the shorter end of the 10um atmospheric window would be absorbed / re-radiated by H2O instead. What we can say is that, all other things being equal, as the earth warms CO2 becomes a less significant GHG.
James Sexton 4:20 pm
Eyes evolved by pure chance, doubtless along with a whole load of other “useless” sensors and probably at all sorts of different sensitivity / frequency ranges. Natural selection favoured those who could see. See?
(It is interesting to speculate on what other senses could be close to mutating into something useful)

Ira, with respect, a comment;
You wrote (in part);
Regarding the incoming (mostly) visible radiation;
“On the left side:
….. (portions omitted for brevity)
The remainder is absorbed by the Surface of the Earth, warming it.”
Regarding the outgoing IR radiation;
“On the right side:
(1) The warmed Earth emits longwave radiation towards the Atmosphere.”
Both of these are entirely correct. But you are missing one small detail, if I might be so bold as to supply a minor edit;
“On the right side:
(1) The warmed Earth emits longwave radiation towards the Atmosphere.” This subsequently causes the Earth to COOL by an amount EXACTLY equal to the energy contained in that packet of emitted IR radiation.
And then of course the reemitted radiation from the gas may return to the Earth thereby warming it again. But this warming must be less than the cooling when the IR radiation left. Thus, no “net energy gain” and no ”higher equilibrium temperature”.
You cannot simultaneously retain energy and also emit it. You can accumulate energy and emit it later thereby de-accumulating it.
I know it is hard to believe that 30 years of very hard work by climate scientists could have such a major flaw. But sometimes folks get so far into the details of the work that the forest is no longer visible since they have been staring at the tree bark.
Nice graphics.
Cheers, Kevin.

Bill Illis says:
February 28, 2011 at 4:40 pm

It is the first time I’ve seen an explanation where the energy represented by the specific frequencies absorbed by GHG molecules are transferred to non-GHGs through collision (and then reemitted by the non-GHGs in the atmospheric windows – almost everyone believes the non-GHGs absorb and emit no IR radiation at all – some bad textbooks mis-educated everyone somewhere along the line).
But then, to show this has a real greenhouse effect (an extra 150 watts/m2 at the surface), the numbers have to be crunched taking into account the time lag between absorption and effective emission to space.
The 10 um atmospheric window actually emits at a higher energy level than it should according to Earth’s temperature alone.
Second, if it was a simple process of 1 CO2 molecule absorbs a 15 um photon and then passes that on to 1 N2 molecule which then promptly emits that to space in the atmospheric window at 10 um, there be no greenhouse effect at all.
The entire process would only take 0.001 seconds for ALL the photons to escape to space. Once the sun sets, the atmospheric temperature should fall to -220C within a second.
But the average time the energy represented by a solar photon spends in the Earth system before it is lost to space is 43 hours. It spends time in 5 billion different molecules before it escapes to space on average.
There is much much more going on here which I would love to see explained to my satisfaction.

Fortunately we don’t have to work through the theoretical quantum physics for every particle in the atmosphere. All we have to do look is look at the surface with a thermal spectrometer from a high altitude and observe the result.
The following is what you see in the infrared spectrum looking upward and downward:
http://www.sundogpublishing.com/fig8-2.pdf
It’s from the 2006 textbook “A First Course in Atmospheric Radiation” by Grant Petty.
Looking downward from 20km over the arctic ocean you can see how much energy is missing in the CO2 absorption band. In the IR window you can “see” right down to sea level which follows the curve of a 265K blackbody. At CO2 absorption frequency of 15um the curve at 265K suddenly drops down sharply to follow the 225k blackbody curve. Using the dry adiabatic lapse rate of 1 Kelvin per 100 meters this gives us an emission altitude of 4 kilometers or about 12,000 feet. At that point absorption and thermalization (transfer of energy to other atmospheric gases) of 15um upwelling radiation by CO2 ceases and it is transmitted directly out to space and follows a colder blackbody curve.
Now, if you reduce the surface temperature of 265K by an amount that’s enough to fill in the hole at 15um (and the other smaller holes in CO2’s lesser absorption bands) to make a smooth blackbody curve at a lower temperature the downward difference is the amount of greenhouse effect by all atmospheric CO2.
CO2 greenhouse effect isn’t linear except for the first 50ppm or so and then it turns into a log curve where additional CO2 has less effect. This is also determined empirically by taking actual measurements of absorption in a laboratory column of gas so it doesn’t rely on theory. I can look up that curve too and have posted a link to it before but don’t have it handy and don’t feel like searching for it again.
The bottom line when the numbers are crunched on the empirical data is a 1.1C increase in surface temperature per doubling of CO2 starting from a baseline of 280ppm with about half of that already a done deal in going from 280ppm to 390ppm today. That 1.1C is the IPCC low end “sensitivity” estimate which isn’t a scary number at all and in fact is a great number because if that’s all it is then the slight warming, mostly in the winter in the higher latitudes, is a great boon to agriculture especially when the biological effect of higher CO2 on green plant growth rates and water consumption is taken into consideration. It’s actually moving the earth closer to an optimum climate where I define optimum as that climate which dominated the earth’s history and in which green plants evolved. Naturally we would expect plants to be best adapted to the environment in which they spent the most time evolving and adapting over hundreds of millions of years. Even if you don’t believe in macro-evolution just about everyone accepts micro-evolution and that’s all we’re talking about is micro-evolution.
In order to sex up CO2 greenhouse warming to a point that might make it scary the climate boffins invented, out of whole cloth with no empircal data to back it up, an imaginary “amplification” where a little CO2 warming increases greenhouse warming by water vapor by twice as much. Following that out to its logical end, since warming is warming no matter the source, water vapor warming will cause even more water vapor warming through positive feedback and we get a runaway greenhouse. In the almost sure knowledge that the earth never experienced a runaway greenhouse even with ancient CO2 levels 10 to 20 times greater than today, these anti-science scoundrels insist with a “high level of confidence” that this amplification is real and it’s based on nothing more than faster than expected surface temperature rise in the past few decades which can be TOTALLY explained by multi-decadal cyclic behavior in ocean currents, trade winds, and/or solar magnetic activity causing small global average albedo changes. There isn’t a lick of evidence that water vapor amplification is more than a figment of fevered imaginations. But CO2 greenhouse effect alone IS real and empirically established.

The mass of the earth is one trillion, that’s 1 followed by 12 zeros, greater than the mass of carbon dioxide in the atmosphere. There is no way that an infinitesimal amount of gas could contain enough energy to significantly change the earth’s temperature. Any heating of the earth is by direct absorption of energy from the sun.

Bryan says:
February 28, 2011 at 2:52 pm
“Your graphs are completely misleading. They show that the intensity of the Solar Radiation as being equal to the Earth surface IR upward radiation.”
The curve seems to depict atmospheric transmissivity rather than quantitative energy transfer, despite its label.
“Further the colder atmosphere cannot heat or “warm” the warmer Earth Surface.”
The colder atmosphere still radiates IR back down, contributing to the total inflow. It’s the net transfer that should be considered.
“All it can do is to slow to some extent the heat loss from the surface.”
Yes, that’s how it works. But the warmists would rather sell you a tipping point with catastrophic thermal runaway, when in fact CO2 is already so close to its maximum effectiveness (critical mass if you like) that increasing it will have negligible further effect.

PS: Because of Robert Woods 1909 experiment with two miniature “greenhouses”, one with a “rock salt” (i.e., transparent to the longwave IR material) window and the other with a glass window, showing NO MEASURABLE DIFFERENCE in the final equilibrium temperatures in both boxes, we’ve known SINCE 1909 that to ascribe the warming of greenhouses to the allegation of a “one way valve” due to the regular sodium silica glass, is in error.
Real “Meteorological” textbooks for many years have noted this and used the prefered term: “Atmospheric Effect”.
I think the WUWT crowd needs to realize this fact and steadfastly refuse to use the terms “Greenhouse gases” or “Greenhouse Effect”.
Truth needs to win!
Max

Oops. Saw a mistake in my last comment. Sunlight penetrates the ocean to roughly 300 feet not 300 meters. That would be 100 meters (give or take depending on turbidity) before it gets inky black. It sucks to be one of those strange people (Americans and Brits) who learnt English units of measure in our youths and has had the rest of the world pressuring us into going metric. I try. Sort of.

Brief note to Myrrh;
All incoming radiation that reaches the surface heats the Earth. It is absorbed by one form of matter or another, which causes kinetic agitation — i.e., heat. It can’t be re-radiated at those same wavelengths because that would require being as hot as the source, the Sun. It gets emitted at the wavelengths matching the temperature of the matter/material emitting. That’s in the IR band for the temps we experience.
In deep space, much material is much colder, and emits at even lower wavelengths, down in the radio bands. Other higher frequency radiation also comes in on those bands after being “red-shift” stretched by the relative recession of the sources from our POV. Such as the putative “Big Bang” cosmic background patterns.

Correction/refinement of above: “All incoming radiation that reaches the surface and is not reflected …”

“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.”
Please don’t go into quantum electrodynamics. The scales involved don’t warrant it and I guarantee you no good will result from it unless further confusion and unending arguments even between the PhD physicists here is your goal.

You know Ira, there’s a quantum explanation for why you squint your eyes in bright lights. There’s also no good reason to ever try to explain it in quantum terms when a macroscopic explanation is far simpler and completely adequate for any practical purpose. The same goes for the greenhouse effect. Quench that desire. Just say no.

Dave Springer,
You use a common graph of the Arctic. I was wondering why you would use a graph of the second dryest place on earth, the dryest being the Antarctic. These would seem to show a much larger absorption by CO2 when water vapor is the largest effect in most other areas on the surface especially since the poles have a lot less energy to radiate.

” Whence arises this uniformity in all their outward shapes but from the counsel & contrivance of an Author? Whence is it that the eyes of all sorts of living creatures are transparent to the very bottom & the only transparent members in the body, having on the outside an hard transparent skin, & within transparent juyces with a crystalline Lens in the middle & a pupil before the Lens all of them so truly shaped & fitted for vision, that no Artist can mend them? Did blind chance know that there was light & what was its refraction & fit the eys of all creatures after the most curious manner to make use of it? These & such like considerations always have & ever will prevail with man kind to believe that there is a being who made all things & has all things in his power & who is therfore to be feared.” —- Isaac Newton…….(emphasis mine)

A useful post and an important topic not often given an airing.
For an alternative view of the long wave effect have a look at:
http://www.climatedata.info/Forcing/Emissions/introduction.html
With regard to the question on variability of outgoing radiation have a look at:
http://www.climatedata.info/Forcing/Forcing/albedo.html

The Late Great John Daly was writing about this kinda stuff (and of “Fraunhofer bands”) over a decade ago in his excellent book “The Greenhouse Trap – why the Greenhouse Effect will not end Life on Earth” … of which I’ve had a copy of for nearly as long.
regarDS

[[[ D. J. Hawkins says:
February 28, 2011 at 8:53 pm
… Your black ball can’t be based on the proportion (molar volume) of CO2 in the atmosphere; it has to be proportional to the effect of the CO2 in the atmosphere. You say it’s a “couple bounces.” I say…does anyone know for sure? Or have a defensible WAG? ]]]
This is not my field of expertise, however, I don’t like treating CO2 molecules like they are magic “heat” beans. Some of the effect attributed to them I regard as speculative or a current theory. I am skeptical about this influence. Every CO2 molecule takes up a measurable space or volume in the airmass. I treat it as a simple molecule and go from there. There are not enough of them floating around to do much in my opinion. Giving CO2 special powers or as you say “proportional to the effect of the CO2” is magical thinking in my book. I suggest that CO2 might bounce energy around but it eventually escapes into space. Heat has to leave Earth otherwise it would keep building up and we would eventually ignite in flames. Our current atmosphere, land, and sea seem to have an intrinsic control mechanism that swings between certain stable limits. I do not believe that CO2 is a zombie monster out to kill us. It is a minor player in “warming”. If we do accelerate a “warming” somehow, I imagine it will just start the reverse swing sooner than it would have happened because we hit the trigger limit faster than its “natural” oscillation . This is only an opinion based on my sum of life experiences so far. I am happy to learn more or be corrected if it can be proven accurate.

May I suggest some consideration be given to the Maxell-Boltzmann kinetic energy distribution curves on which subject Tom Vonk made an excellent post here on WUWT a while back.
http://ibchem.com/IB/ibnotes/full/sta_htm/Maxwell_Boltzmann.htm
http://dwb.unl.edu/teacher/nsf/c09/c09links/www.kobold.demon.co.uk/kinetics/maxboltz.htm
To me these effects imply that most long wave radiation absorbed by GHGs in the atmosphere is thermalised and “back radiation” is not related to the MASS of the GHGs in the atmosphere. A simple example is compare average surface temperatures at or near the equator to the average surface temperatures in the desert regions north or south of the equator. True there is more cloud at the equator because of the higher humidity but why doesn’t the temperature rocket up when the sky is clear? I have lived for some years in Singapore and never experienced temperatures there that I experienced in the Namib desert. Yet which region has the most “greenhouse” gases?

“A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because “greenhouse gases” (GHG) absorb outgoing radiative energy and re-emit some of it back towards Earth.”
Has WUWT become a “lukewarmer” site and abandoned Climate Realism?
This is pure nonsense and I’m surprised that WUWT would print such rubbish. Infra Red Interacting Gasses (IRIGs) CANNOT heat the earths surface. To do so would mean the colder air is warming the hot ground and that goes against the laws of thermodynamics.
Clearly impossible! (See slaying the Sky Dragon ).
The “greenhouse effect” on earth actually does work much the same as an actual greenhouse. It is due to the relative slowness of convection that keeps the earth surface from instantly freezing at night.

Ira, a couple more comments.
The temperature of the sun is in fact an artifact of its radiance. The sun’s actual temperature ranges from several millions of degrees at its core to about 3 million degrees in the very diffuse corona above the “surface”. The photosphere or “surface” is sandwiched between these extremes and behaves as if it were a black body at 5840K. This can be determined approximately by its total power output and peak wavelength and accurately by its absorption lines which are temperature dependent. This does not contradict anything you said but may reassure those who look at the very low temperature and think “how can that be true?”.
Secondly I have re-read your paper and realised that there is something I do not believe is correct. It relates to the point I made in my earlier comment to George E Smith and was restated rather more strongly by Tim Folkerts when he said “I must disagree with the comments to the effect that N2 & O2 radiate (or absorb) any important amount of IR”.
You talk about the “7 and 15 micron photons” being absorbed and then some of this energy being passed to other gas molecules and being re-radiated as “10 micron photons” with some of these being lost to space. This implies that there are gas molecules around that can radiate at this wavelength. However if there were then there would not be an atmospheric window. The very reason that this window exists is that there is no absorption and therefore no radiation at these wavelengths.
Incidentally, I may be wrong but, I get the impression that some posters believe that there are two types of radiation: radiation at specific wavelengths and blackbody radiation. In reality black bodies are radiating and absorbing at specific wavelengths it is just that they do so with 100% efficiency at all wavelengths. A grey body also absorbs and radiates with the same efficiency at all wavelengths but does so with less than 100% efficiency.
The earth is close to being a grey body for the infrared part of the spectrum where it emits but it is not a grey body in the visible region. That is why the sea is blue! The atmosphere is nothing like a black or grey body and can never behave like one. As I explained in my previous post the combination of the earth’s surface and the atomosphere results in the grey body emission of the surface being modified by the absorption bands of the IR absorbing gases like H2O and CO2 to give dips in the spectrum particularly around 7 micron and 15 microns when viewed by satellites.

Brian H says:
February 28, 2011 at 7:49 pm
Brief note to Myrrh;
All incoming radiation that reaches the surface heats the Earth. It is absorbed by one form of matter or another, which causes kinetic agitation – i.e., heat. It can’t be re-radiated at those same wavelengths because that would require being as hot as the source, the Sun. It gets emitted at the wavelengths matching the temperature of the matter/material emitting. That’s in the IR band for the temps we experience.
Brian, I have a real problem with that explanation in the graphic that it’s only Visible and near shortwave that heat the Earth kinetically, a.k.a. “Solar”. Your “all incoming radiation reaches the surface of the earth” isn’t addressing that, because that’s what I’m saying is happening… Because all radiation includes Thermal IR which isn’t in the chart.
Ira says that Visible is the largest part of the Sun’s spectrum, wrong, it’s actually the smallest, and compared with the others, very very small. Light is not hot, it is Reflective not Absorptive, and your use of “absorbed by matter of one form of the other” is misleading. The radiation that penetrates to heat the Earth is Thermal IR. And that is not in the Chart.
So, not only is downwelling Thermal IR taken out of the equation, it is replaced by the very strange notion that Visible light and its two other cool neighbours, by themselves heat the Earth, called “Solar”. I can sit infront of the TV all day in a cold room, it won’t heat me.
What I want here is conclusive proof that it this narrow band of non-thermal light energy which is the sole cause of the ground and rocks and me heating up from the Sun. That’s basic premise to the AGW Energy Balance claim as shown in the Charts.
And no, it does not require the source to be as hot as the sun to radiate out Thermal IR, the electric plate on your stove doesn’t have to be even hot enough to produce red light for you to feel the IR it is radiating, but that doesn’t mean that the Sun isn’t radiating our Thermal IR! That’s reaching the Earth at the same time as Solar. And is better going through water vapour, fog and mist, than Visible Light.
The Earth being heated by kinetic energy alone by Solar without any mention of of the Absorptive energies from the Sun of Thermal IR is nonsense, which is the AGW claim. I’m asking for proof it isn’t nonsense.

In addition to the problems in the main post, there are numerous errors in the comments.
George E. Smith says:
“The AGW types, like the frequency scale, because that puts the CO2 frequencies near the peak of the curve”
Actually, the frequency (wavenumber) scale gives a more intuitive plot when discussing the amount of energy. Note, the wikipedia graph uses log of wavelength which completely distorts the plot.
“the actual amplitude of the thermal spectrum should be about 80 times smaller than it is.”
Well, that depends on the x-axis selection. When frequency (wavenumber) is selected, it is the solar spectra that is about 28 times too high. When wavelength is selected, the 300K curve should be about 10 times smaller.
“The only function of the GHG molecules is to heat the atmospheric gases; along with all the other mechanisms that are heating it. After that, the GHG molecules serve no function in the climate process whatsoever.”
True, they do heat the atmosphere .. however, they also cool it. In fact, greenhouse gases provide the only method to cool the atmosphere. Note that some of the energy they release returns to the surface producing the greenhouse effect.

John of Kent says:
Has WUWT become a “lukewarmer” site and abandoned Climate Realism?
This is pure nonsense and I’m surprised that WUWT would print such rubbish. Infra Red Interacting Gasses (IRIGs) CANNOT heat the earths surface. To do so would mean the colder air is warming the hot ground and that goes against the laws of thermodynamics.>>>
Oh my.
There’s so many things wrong with those few sentences that it would take paragraphs to correct them all. I sometimes wonder why it is that when science is well explained on this site, by highly technical people, who then engage in well informed debate and discussion with other highly technical people, the bulk of whom are skeptics or mild luke warmers at best, there is always some troll jumping in, spouting rage and ridicule, and denouncing the explanation as fraudulent? And why does the criticism almost always include the exact same two statements?
1. Cold things can’t heat up warm things.
2. That breaks the laws of thermodynamics.
Is there some secret troll society somewhere, a cabal of warmists perhaps, determined to mess up every serious discussion of greenhouse effect by shouting those two statements? Are they on a web site someplace worded a dozen different ways so that volunteers can just copy and paste to distract everyone else? Or maybe it is completely automated?
OK Kent, cold things can’t heat up warm things. Igloos freeze everything inside them to death, that’s why the Inuit are extinct. The laws of thermodynamics don’t allow for net energy transfer. That’s why if you take two very hot things at the exact same temperature and put them side by side, there’s no energy transferring between them so you won’t burn yourself if you stick your hand between them, the laws of thermodynamics say you’ll be just fine. Kent…KENT KKKKEEEENNNNTTTT don’t actually do it!!! Phew. I thought you were going to try it. Would have felt bad about that.
There’s dozens of threads and hundreds of comments on this site from very well informed skeptics (amongst others) explaining the facts. You would do well to read many of them before popping off with comments that can be falsified by building an igloo.

When it comes to our little blue planet, all this hypothetical analysis of incoming and outgoing radiation in various wave lengths, and how much is reflected back and how much escapes is neatly summed up by by Humphrey Bogarde, It does not amount to a hill of beans. The amount of heat our world receives and its reaction to it gives us our chaotic but wonderfully variable climate. I find it some what incongruous that people find small changes in things like CO2 can cause warming and cooling besides drought and floods, not to mention no snow or massive snow. The entire argument is total nonsense. It is and always will be the sun and solar mechanics that control climate, anything else will be but a bit player and not relevant to our climate.
We have a heat pump Earth that uses water and water vapour as a control mechanism every thing else is irrelevant. It is time to ask our great sun god Sol to awaken for the energy balance is tipping to the cool side. As our moderating fluid in the oceans cool as it would seem is happening no amount of nit picking as to what IR radiation is going up or down is going to be diddlysquat as far as our well being is concerned.
The world has suffered a concerted propaganda effort by the by so called experts to brain wash the west into believing that we are evil polluting monsters, AGW never was about global warming, it was about control power and wealth distribution.
Discussing radiative imbalances is a digression to keep those with cognitive thought busy whilst evil is committed.
Those here on this site show huge education and intelligence but this subject has nothing to do with global warming the IPCC is totally political with no real science involved. Confound the science of global warming all you like but the politics and the lies will keep overwhelming you in the compliant MSM.
It is time for a different tack for the science is becoming irrelevant as the brainwashing of the young is total in the schooling system. I have no answer but many on this site are far more intelligent than I and may have an antedote to this modern day grab for control. Cheers Wayne

Dave Springer comments at February 28, 2011 at 7:36 pm are well worth a read, especially the point he makes aboud clouds (a point I made in my earlier post).
Whilst CGR may be an explanation for changes in clouds/cloud seeding/ cloud patterns, there may be other explanations for these changes. Indeed, in a chaotic system (such as weather/our atmosphere) one would expect there to be changes in clouds and their patterns. Further, given that we are looking at such a small time scale (circa 100 years) it would not be surprising if during such a short period there was a tendancy (ie., a trend) for less cloudiness and hence a slight upward trend in temperature. This might be nothing more than natural variation on the time scales that we are looking at.
Personally, I consider that an explanation along these lines is a more plausible explanation (by many orders of magnitude) over that of CO2 being responsible for the warming. Given that current computer models do such a poor job with clouds, we cannot rule this out.

Tim Folkerts says:
February 28, 2011 at 7:23 pm
I must disagree with the comments to the effect that N2 & O2 radiate (or absorb) any important amount of IR.
Look at a somewhat similar and more familiar idea – visible light emitted by a Hydrogen atom (the Bohr model covered in freshman chem & physics around the world). It is easy to observe that H only emits very specific energies of light which are “easily” predicted by the quantum mechanics of the orbiting electrons and the allowed transitions between energy levels of those orbits.
————————————
But the Sun emits mostly like a blackbody.
It is not being emitted in the Hydrogen frequencies only, it is emitting across the entire spectrum close to what the blackbody curve predicts. If anything the Hydrogen spectra are suppressed (much like the CO2 spectra is suppressed on Earth) and it emits a little more energy in the non-specific-absorption frequencies (more in the visible).
The absorption and emission spectra bear special attention, but not all the attention.
http://commons.wikimedia.org/wiki/File:EffectiveTemperature_300dpi_e.png
http://en.wikivisual.com/index.php/Image:Solar_irradiance_spectrum_1992.gif

Unfortunately the text in the figure is incorrect.
It says: Downgoing solar radiation 70-75% transmitted. The part not transmitted (but reflected) is not downgoing anymore. This may seem pedantic (it probably is) but it informs the howler at the right: Upgoing thermal radiation 15-30% transmitted. This has to be: All, that is 100%, of the upgoing thermal radiation is transmitted (else it would not be upgoing anymore). The atmosphere is in long-term equilibrium which means that all thermally emitted radiation is in balance with the loss at the top of the atmospher to space. The semantic mistake is an indication that the maker of the figure confused the outgoing flux with the local source function.

Robert Clemenzi says:
………”Several people have said that a cold sky can not heat a warm surface. The truth is that it can.”……
A warmer surface will radiate more of every wavelength than it absorbs from the colder surface.
How then can we say the colder surface “heats” the warmer surface?
Heat means to “increase the temperature of “.
In fact it is more correct to say that the colder surface slows the rate of heat loss from the warmer surface.
In other words it insulates the warmer surface to some extent.
The igloo example will insulate the person inside to some extent.

Tim Folkerts says:
February 28, 2011 at 7:23 pm
“However, it is an observed fact (supported by theory) that monatomic gases (like argon) or symmetric diatomic gases (like N2 and O2) do not have vibration modes or rotation modes that would allow them to absorb (or emit) IR photons.
… IR is not absorbed or emitted by N2 & O2.”
A hot body that won’t radiate infrared?? That’s gotta be the best-kept secret in physics, if it’s true.

John of Kent,
“To do so would mean the colder air is warming the hot ground and that goes against the laws of thermodynamics.”
Wow. Against the laws of thermodynamics. Which laws of thermodyamics did you have in mind? First law says that energy can be changed from one form to another but cannot be destroyed. That can’t be it then. What about the second law? Perhaps that’s what you meant. Let’s see. Here’s a quote about that from Wiki:
“The second law of thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system. From the state of thermodynamic equilibrium, the law deduced the principle of the increase of entropy and explains the phenomenon of irreversibility in nature. The second law declares the impossibility of machines that generate usable energy from the abundant internal energy of nature by processes called perpetual motion of the second kind.”
Talks about a tendency of temperatures to equilibriate and the impossibility of perpetual motion machines. Ok, if the colder air is supposed to be radiating towards the warmer ground, is that against the second law of thermodynamic?
Not necessarily. As long as the warmer ground is radiating more back towards the cold air than the cold air is radiating towards the warmer ground, their temperatures would equilibriate (if the ground wasn’t being continually warmed by the sun). Does this mechanism constitute a perpetual motion machine? No, because again, their temperatures would equilibirate over time so no more work could be done.
By this definition of the second law, GHG back radiation to earth does not violate it. Care to elaborate?

Anthony, I wish WUWT would follow Max Hugoson’s advice — atmospheric effect. Truth in science.
Max Hugoson says:
February 28, 2011 at 7:34 pm
PS: Because of Robert Woods 1909 experiment with two miniature “greenhouses”, one with a “rock salt” (i.e., transparent to the longwave IR material) window and the other with a glass window, showing NO MEASURABLE DIFFERENCE in the final equilibrium temperatures in both boxes, we’ve known SINCE 1909 that to ascribe the warming of greenhouses to the allegation of a “one way valve” due to the regular sodium silica glass, is in error.
Real “Meteorological” textbooks for many years have noted this and used the prefered term: “Atmospheric Effect”.
I think the WUWT crowd needs to realize this fact and steadfastly refuse to use the terms “Greenhouse gases” or “Greenhouse Effect”.
Truth needs to win!

“Mars is a lot further from the Sun than is the Earth, which is the main reasion it is too cold to support life as we know it, despite all the CO2 in its Atmosphere.”
No, Mars isn’t at a “beyond supporting life” distance from the sun. The Martian atmosphere would be warm enough to support life if it wasn’t so thin , at about 1% the density of Earth’s atmosphere. The density of the atmosphere ties in directly with it’s heat capacity. Mars has little to no magnetosphere, so the solar wind stripped much of the atmosphere away over billions of years.

Ira Glickstein, PhD says:
March 1, 2011 at 7:19 am

I googled images for “outgoing infrared spectrum” and found this:
http://www.skepticalscience.com/images/infrared_spectrum.jpg
“It should the spectrum looking up from somewhere in the arctic on a clear day and the view looking back down from 20 km. The incoming radiation would be the re-emitted IR from the atmosphere that you wanted. It clearly shows the 7 um, 10 um and 15 um bands Ira is talking about.”

If you’d paid attention to MY comments you’d have found that image months ago. I have posted it several times including last night on THIS thread.
http://www.sundogpublishing.com/fig8-2.pdf
It’s from the 2006 textbook “A First Course in Atmospheric Radiation” by Grant Petty.
I didn’t know you could get a PhD in Obfuscation & Convolution but you’re living proof that it happens.

The charts from skepticalscience are very interesting.
They do not appear to be readings taken at the north pole on January 7th., nor at Tucson on July 9th.
I would be very interested in reading how they are put together.

Peter Taylor;
It took me a long time to realise that the Radiative Forcing (RF) that is at the heart of the model calculations is centred on a notional point toward the top of the troposphere…defined by the temperature at which the earth will reradiate the balancing energy – which is -19 C and about 10km up>>>
This was one of my very first epiphanies in regard to the IPCC numbers. They keep quoting 3.7w/m2 and 1 degree, but a quick SB Law calculation versus temp at earth surface doesn’t support that. From your post it sounds like you couldn’t find the supporting docs in AR4, but I did. I’d have to dig like crazy because it was a long time ago, but from memory:
IPCC calculates sensitivity at the “theoretical black body” temperature of earth. I thought it was -15, but could very well have been -19
They specificaly state that surface temperature changes cannot be directly related to changes in RF. In fact, they even say it is possible that a change in RF results in climate change, but potentially NO surface temp change.
The implication that CO2 is linear was very carefully worded, but turned out to be a reference to a small change of some sort where treating it as linear was a reasonable approximation. BUT, if you go to the section on ECONOMIC scenarios, that make it VERY difficult to work the numbers backward to CO2 concentrations, but the log functions are very clear in those sections.
This subterfuge is very misleading, deliberately so, and I’ve remarked on it often. If someone wants to write a detailed expose, I’ll be happy to go scrounge up all the references even if it means reading the whole d*** thing again.

I thought it was still a matter of dispute whether a gas (the molecules in a gas) behaved/radiated according to BB “laws”. There seem to be very positive opinions being asserted above that hinge on that specific issue.
BTW Ira, I’ve just gone thru the first part of your novel, and I wonder if you still “believe” the scenarios and causalities for climate behavior and fluctuation you posit and “explain” in Chapter 1. The verbiage circles round and round, but boils down to domination by CO2 changes, with some drastic natural and not-so-natural interventions and intervening events forcing it back down to “normal” levels.
Which, IMO, is alla buncha hooya.

Many thanks, Ira, for a clear explanation, and I understand that you have only attempted to describe the radiative effects in this post.
My view is that the term ‘Greenhouse Effect’ is dead right because it describes exactly how a greenhouse does not work. A real greenhouse works just as well with polythene, styrene or, classically, rock salt windows because, although the blocking of long wave IR is real it’s irrelevant compared with the greenhouse’s blocking of the convective currents which are the main mechanism for removal of hot air, directly and by evaporation.
Similarly, although I’m sure there is a radiative effect which would be active in a static atmosphere, the real atmosphere is anything but static, being thoroughly turbulent and full of convective cells. Radiation thus only comes into effect at the top of the troposphere, where the density of all gases is too low to do much blocking.
In my view the talk of radiative physics is a waste of time since it’s an extremely minor effect.

Wow! There are soo many problems and issues being thrown around that it is nearly impossible to address everything. As someone with a degree in physical science (including physics and astronomy) I guarantee you cannot learn the basics from one page, let alone all of the complexities, e.g. spectroscopy.
I just want to cover four simple items and see if I can provide other insight later:
1) Steve at 141 is correct: The nearly absent atmosphere is the reason Mars is so cold. Other comparisons: the Moon vs the Earh (basically the same distance from the Sun but no atmosphere on the Moon) and Mercury vs Venus (Venus is further away but with an extemely dense, CO2 heavy atmosphere which causes Venus to be much hotter than Mercury).
2) On a large scale (planetary), the method of heat transfer is radiation. There may be convection and conduction within the atmosphere (up to about 10 Km as found by E. O. Hulburt in 1931), but between the Earth (including the atmosphere) and “space”, heat is transferred via radiation since space is a vacuum (you need matter for conduction and convection, also shown by Hulburt in 1931).
3) CO2 and H2O
Ugh, this comes up soo often it is getting tiresome. So let’s look at two pieces of information.
3a) Absorption by components
Please look at the following picture showing the absorption from CO2 and H2O, as well as other constituents. While water is a broad absorber of long wave IR radiation (greater than 10 microns), it is not complete. But look at CO2. This is very important. There is a major absorption feature between ~13-20 microns which is very good at absorbing LWIR radiation. This is important becasue H2O does not completely absorb the radiation in this wavelength region. So when CO2 levels increase, it further impedes LWIR radiation from escaping the atmosphere. This is even more important since according to Planck’s law, a blackbody at the Earth’s surface temperature will radiate in this wavelength region. While the Earth may not be a blackbody, it does radiate in this spectral region.
3b) Composition of atmosphere relative to CO2 and H2O
H2O is primarily limited to being located close to the surface of the Earth and is not well mixed into the entire atmospheric column, unlike CO2. However, when we look at things spectrally, it does not matter if the gas we are looking through is localized in a small area or spread out through a larger area/volume (ignoring clouds of course). It will have the same effect. When we measure gases using spectral instruments, we need to take into account the distance from the source to the sensor. We calculate the amount of the gas we see and divide by the distance and get an average over that distance. Same is true when looking down from a satellite towards the Earth. When we consider the entire column we find:
H2O: ~0.40%
CO2: ~0.04%
While H2O is higher than CO2, it is not orders of magnitude larger. The challenge is that the H2O amount is not changing by 100%. Remember from 3a, CO2 is absorbing outgoing radiation where H2O is not and the amount of CO2 is increasing.
4) Be careful with these plots and simple explanations. Total absorption and opaque are not quite the same, i.e. if 100% is already absorbed than more CO2 cannot be a problem. The graph at the top of the page suggests that the atmosphere is a single step from Earth to space. In reality, models use multiple levels to account for the differences in gas constituents at various heights.
Last lesson: Be very careful with LWIR. Most people are okay with near IR and short wave IR since this radiation is identical to visible sunlight, which we are accustomed to as humans since our eyes are optimized for that region. In this part of the spectrum, we talk about reflection and absorption. But when we head towards long wave IR, you have absorption/emission, transmission and reflection. It is a somewhat messier region that can be easily confused. Most people familiar with LWIR come from a lab setting using instruments in a controlled setting. But when you start looking at/using the atmosphere, it becomes a much more difficult problem.
Hopefully NASA’s Glory satellite may help answer more questions when it finally launches.

Hi Oliver,
I like these discussions because they have been encouraging me to remember my IR skill set.
Yes, it’s a surface condition effect. And it is quite dramatic.
But what I suddenly realized, from this discussion is something that I had not thought of before.
The stars. Outer space.
Do you realize that it impossible from earth to know whether all the ‘stars’ that are seen in the sky, or from space, are indeed really ‘stars’ and not ‘reflections’ from massive pure metallic bodies, or perfect reflectors, of nearby true stars?
It is literally impossible to know from a distance. Impossible.
Now that is wild.
I have never seen that idea looked at in astrophysics.
But from a radiational physics point of view, it is entirely possible.

“”””” _Jim says:
February 28, 2011 at 3:45 pm
George E. Smith February 28, 2011 at 3:23 pm :
…
So the atmosphere does radiate a black body like thermal spectrum, and the presence of the gHG molecules simply means that there will be bands of that continuum emission, that are also captured by the GHG molecules, as well as the emissions from the surface.
I’ll wait to see how this is adjudged.
(IR Spectroscopy explaining spectral response regarding gas molecule vibrational modes would seem to indicate otherwise.) “””””
Jim needs to take remedial English Reading courses. IR Spectroscopy indicates nothing of the sort.
The IR Spectroscopy item you cited, refers to ABSORPTION SPECTROSCOPY which as it properly indicates, relates to RESONANCE MODES which are indeed characteristic of specific molecules, and their excited state energy levels.
No where did I make any statement that is inconsistent with this; it is the reason we talk about the “15 micron” or 666 cm^-1 degenerate bending mode of the linear CO2 molecule. It is degenerate since there are two identical and indistinguishable modes at right angles to each other; each of which can gather its own photon.
But the question which you chose to challenge, is the quite different THERMAL SPECTRUM EMISSION; which has nothing whatsoever to do with atomic or molecular structure or energy levels. It is a classical physics consequence of the accelerations of electric charge; which according to Maxwell’s equations must (and do) result in the radiation of an EM wave (or photon if you wish; which has a continuous energy spectrum; not a quantized one. Ordinary atoms, once ionized by the removal of one or more electrons, also emit a continuum EM spectrum, which is not quantized, because a newly captured free electron can have any initial energy before being captured by the ion.
The accelerations of Electric charge in molecular collisions, are entirely unpredictable as the the redistribution of momentum and energy; although one can talk statistically about expected distributions.
One can learn a thing of two from the Particle Accelerator Physicists. The Stanford two mile long electron linear accelerator is one of if not the most powerful electron accelerators in the world. It is linear, because then the only acceleration the electrons see, is due to the accelerating electric (traveling) waves in the beam line. On the other hand circular track accelerators, have to steer the beam around corners continuously to get them to repass through the accelerator gaps, and gain more energy. To compensate for this increased energy, the bending magnet fields have to increase synchronously with the particle energy, to maintain them in the correct orbits. Since the charged particles are traveling in a circle, they are subject to a continuous acceleration, since acceleration is a change in velocity and velocity is a vector quantity, having a direction as well as a “speed”.
So particles in a circular accelerator continuously radiate, EM energy as the go around the track. Well pedantically, the path is a number of curved arcs, interleaved with a number of straight sections, and it is only in the arced sections that the particles radiate.
So the reason why proton beams can be accelerated in a circle, and electrons can’t (beyond certain energies, is that the proton is far more massive than the electron.
So consider two neutral atoms (or molecules) colliding. Each molecule or atom is electrically neutral, so the electrons will go more or less, where the protons in the nucleus goes (on average), but in the process of collisions and recoil of the particles, the more massive nuclei consisting of Protons, and Neutrons, undergo far lower accelerations, than do the much lighter electrons; so even though and single atom or molecular is electrically neutral, in collision, the electrons undergo much higher accelerations than do the Protons or nuclei; so just as in the particle accelerator, it is the electrons that radiate the EM wave energy, and the much smaller opposing field due to the proton accelerations does not compensate. So one can practically ignore the proton positive charges, and consider only the acceleration of the net electron charge to figure out the radiated EM fields.
The thermal radiation continuum depends only on the Temperature, and has a BB like spectrum, that does not depend on the atomic or molecular species; only on the Temperature.
Some of you people need to get your noses out of facebook, and wiki, and hit some Physics books, to learn what you should have learned around the 8th grade.
Nothing in the IR Spectroscopy paper you cited is inconsistent with that; they talk ONLY about absorption spectra; not emission.
And Kirchoff’s law applies only in equilibrium, and the atmosphere is never in equilibrium.

[[[ Ira Glickstein, PhD says:
March 1, 2011 at 6:01 am
…Your analogy of the black balls in the pool does not work because the mechanism is not at all like that of the “greenhouse effect” GHG in the atmosphere. There is more H2O (the main GHG) in the Atmosphere than CO2, but the percentage of H2O is also miniscule, yet, the tiny percentage of GHGs (mostly H2O but also CO2) are responsible for the Earth being at livable temperatures. ]]]
OK Ira,
I agree that Earth’s Atmosphere helps make our Earth livable. I think water in all three states, solid, liquid, and gas, clearly plays the major role. The alleged “CO2 effect” is critical that it be accurately quantified, as it is being considered a “problem” and will cost us all dearly (money) if current politicians impose their planned restrictions.
I want to shrink the “alleged CO2 effect” to a simple provable visual experiment that the average layperson can easily absorb. Some of the material presented in this wonderful blog is quite advanced and beyond the expertise of many lay readers.
How about this…..
1) Chill 1 bottle of distilled water and 1 bottle of CO2 injected mineral water in the refrigerator (to keep the CO2 in solution).
2) Find 2 identical glass or plastic bottles with a screw top that seals.
3) Place a thermometer upsidedown in each bottle so the bulb won’t be in the liquid.
4) Fill each bottle half way with identical volumes, one with distilled water, the other with the CO2 impregnated mineral water.
5) Secure the cap and place in full sun on the window sill.
6) Keep room temperature just slightly below the thermometer temperature as it changes.
7) If CO2 really does have a big influence in keeping Earth warmer, at some point in the experiment either during the day, or at sunset, or in the evening, or at night, the air above the mineral water should be warmer.
Both will have a mix of normal atmosphere and water vapor, but the mineral water will have released additional CO2 into its “atmosphere”, boosting its “greenhouse effect” that will keep retained/reflected heat in its sealed environment.
Remember to keep the room temperature just slightly below the bottle temperature to keep any heat transfer influence from the room air at a minimum.
If there is a “CO2 effect” it should show up here on the thermometers.
How about this one Ira?

“”””” Mark Nodine says:
March 1, 2011 at 12:35 pm
Thanks, Ira, for an interesting post.
I think there is an important point, however, on which your analysis is misleading. I agree with George E. Smith (February 28, 2011 at 3:23 pm) that the IR absorption occurs by exciting the vibrational modes of GHGs. The reason that N2 and O2 and H2 do not absorb IR is not that they have no dipole (since neither does CO2), but because, being diatomic, they have no asymmetric vibrational modes, which are the ones that absorb in the IR range. George is right in saying that the vast majority of the absorbed light rays are immediately reradiated and do not have time to affect the thermal distribution of the surrounding gases. “””””
Well Mark, you were doing ok until you said this:- “”””” George is right in saying that the vast majority of the absorbed light rays are immediately reradiated and do not have time to affect the thermal distribution of the surrounding gases. “””””
Because absolutely never in my life have I ever said any such thing; the exact opposite in fact.
The CO2 (or other GHG molecule) certainly absorbs specific LWIR energies, according to the energy levels of its excited molecular states; ” BUT ” in the lower atmosphere it NEVER (hardly ever) has enough time to re-radiate that absorbed Photon, at the same energy and frequency (wavelength). Molecular collisions happen many thousand times faster, than spontaneous emission at specific (CO2) frequencies. The energy is lost in thermalization collisions, which warm the ordinary gases of the atmosphere. From that time on, the GHG gas molecule has no influence whatsoever on what happens. The (slightly heated) atmospehric gases now radiate a complete thermal spectrum continuum, depending ONLY on the atmospheric Temperature; AND THEN the CO2 or other GHG molecule can re-engage with THAT spectrum, and once again carve out its specific absorption band chunk.
The proof of this is in the satellite (and calculated) LWIR spectra of the earth. They are BLACK BODY LIKE SPECTRA with the GHG absorption band partly missing (attenuated) by the GHG molecules.
If the only LWIR emission from the atmopshere was from the GHG molecules, itwould be ONLY at th4e specific GHG resoanance absorption band frequencies; and it is not; it is a full BB like spectrum.
You have to note that the actual spectrum is the overlaying Temperature BB spectrum, MODIFIED by the spectral radiant emissivity of the radiating material.
Since a thin gas layer, has few molecules, it has a correspondingly low emissivity.
A 50 Angstom gold film, also has a correspondingly low emissivity; but of course higher than the gas layer, because it still has a greater atomic or molecular density.
There is nothing in the phase transition from solid ice, or liquid water, to H2O vapor by sublimation or evaporation; that suddenly turns off the ability of those molecules to emit a BB like thermal continuum radiation spectrum according to Planck formula and other applicable laws (don’t forget the emissivity).
But I have never said the the atmospheric LWIR spectrum consists of the GHG resonance absorption frequewncies only.
That condition is approached in the stratosphere, when molecular mean free paths, and intercollision times become long compared to the lifetimes of the excited states. Then the spontaneous emission can occur; but the molecular density is so low, that it cannot be a significant contributor to the total earth LWIR emission spectrum.

to Izen
you wrote: “But the research on radiative transfer carried out in connection with heat sensor/seeking systems for military purposes would seem to make it unlikely that any such major error has gone unnoticed.”
Heat seeking systems are ridiculously simply compared to accurate quantification and complete summation of thermal radiation properties for specific gases.
Heat seeking sensor systems only need a ‘window’ or two, or three to locate a target.
Heat seeking sensor systems are qualitative in nature, not quantitative. The military doesn’t care much about the details. They just want to find and lock onto the target.
If you had any experience with quantifiable IR, you would know this.
And that is one of the biggest problems. Much research about atmospheric IR has been done by the military in order to locate and track heat signatures. But that data is really of minimal use when absolute quantification is necessary for establishing real world temperature effects of gases in the atmosphere regarding ‘greenhouse effects’.

“”””” Dave Springer says:
March 1, 2011 at 7:53 am
Enough already with the argument that certain gases that don’t absorb infrared can’t emit it. This is not true for dense gases. The troposphere is a mixture of cold dense gases. Please review Kirchoff’s Laws:
http://www.physics.rutgers.edu/~matilsky/documents/kirchoff.html
Radiation Laws
Kirchoff’s Laws
First Law: A hot solid, liquid, or dense gas emits radiation at all wavelengths (“a continuous spectrum of radiation”). For example, a perfect blackbody does this. If the light were passed through a prism, you would see the whole rainbow of colors in a continuous band.
Second Law: A thin hot gas in front of a cooler background emits radiation at a discrete set of isolated wavelengths. These discrete, isolated wavelengths are called the “emission lines” of the spectrum, because if you were to pass the radiation through a prism, you would see isolated lines of different colors. The whole spectrum is called an “emission-line” spectrum. The wavelengths of the emission lines are unique to the type of neutral atom or ionized atom that is producing the emission lines.
Third Law: A thin cool gas in front of a hotter solid, liquid, or dense-gas background removes the radiation from the background source at special wave lengths. If the resulting radiation were passed through a prism, there would be dark lines superimposed on the continuous band of colors due to the background. These dark lines are called “absorption lines.” The wavelengths of the absorption lines are unique to the type of neutral atom or ionized atom that is producing the emission lines.
If a certain type of gas produces absorption lines at certain wavelengths when it is in front of a hot background, then when that same type of gas is seen in front of a cooler background, it produces emission lines at the exact same wavelengths.
Explanation of Kirchoff’s First Law
Kirchoff’s First Law boils down to blackbody radiation, since solid objects and dense gases emit radiation like blackbodies.
Explanation of Kirchoff’s Second and Third Laws
Thin gases don’t emit or absorb radiation like blackbodies. To understand their emission and absorption, we must consider the structure of atoms, as described by Quantum Mechanics. “””””
Well I found this citation from Dave Springer; about “Kirchoff’s Laws”.
Would people please read what Rutgers University says about those laws; and please take note of all of the words, in their explanation.
Notice their reference to THIN HOT GASES and THIN COLD GASES. Note the “”””” THIN “””””
Those nice Balmer spectra and the like from Mercury vapor lamps or Sodium lamps and the like are observed in VERY LOW DENSITY gases, where the mean time between molecular or atomic collisions is much longer than the lifetimes of the excited states, so that spontaneous emission can occur; only then do you get the bright line spectra as seen in those HOT gases.
But the earth’s lower troposphere is neither low density nor hot; it is 288 K on average worldwide (so they tell us), and the molecular collision rates are thousands of times faster than the excited state lifetimes, so spontaneous emission almost never occurs in the lower troposphere.
But the molecular velocities of thermal motion of atoms or molecules; and especially molecules being more massive, are way lower than the vibrational mode velocites of the excited state resonances, so the resulting electron accelerations in intermolecular collisions, are much lower, hence the magnitude of the thermal radiation fields is way down in the mud, which is why it is so hard to observe.
But the fact remains, that the spectrum which is supplying the GHG resonance energies , is akin to that radiated by an ordinary yard brick or a bottle of water, at room Temperature. That radiation is 10,000 times lower in radiant emittance, than the radiation form an ordinary 100 Watt “heat lamp”, that emits radiation that is absorbed by human tissue and registers itself as what we call heat; and it does so, because we are mostly water, and absorb strongly at the 1 micron wavelength of the heat lamp emissions.
Humans do NOT perceive 10 micron 288 K radiation as producing heat, because it is only 400 W/m^2, and not 4 million W/m^2 that the heat lamp emits.
But jsut because we don’t sense it, does not mean the atmospheric gases are not emitting it.

Richard Smith,
You say “But the greenhouse effect according to climate ‘science’ is not the insulation of a blanket or a reduction in the rate of cooling, but a positive addition of heat (33C or more) because of ‘backradiation’. If this theory were true it would mean that the Earth emits more energy than it receives. This is a contravention of the laws of thermodynamics.”
Surely, if temperatures are rising, (as posited by the GHG hypothesis) it must mean the exact opposite – namely that the Earth emits LESS energy that it receives. Therefore this is not a contravention of the laws of thermodynamics as you assert.
You then say “It is based on the fallacy that if the escape of heating is blocked, then the temperature will continue to rise until a ‘radiative equilibrium’ is reached . . ”
If a proportion of escaping IR is radiated back down to Earth then temperatures must increase. As this happens, then more energy is radiated from the Earth at a flux density that is proportional to the fourth power of the increase in temperature. The idea you suggest where “the heat bursts through the barrier,” although meant to be a derisive dismisal of the GHG mechanism, actually misunderstands the issue. It is a simple application of the Stefan-Boltzman equation for blackbody radiation that gives an increase in radiative emissions from Earth, until it once again equals the radiation coming into the Earth.
Your final remark “If it were true we could generate huge amounts of energy from a small input simply by placing an infra-red barrier around a radiator – just tap some of the heat off at regular intervals – free energy,” is completely false. There is nothing about a mechanism that radiates energy back to the Earth and resulting in a temperature increase, that lends itself to the notion that this can in any way lead to free energy. If you try to drain energy from the atmosphere all that would happen is the atmosphere would cool down and the Earth would radiate faster and cool down more quickly. I suggest the same thing will happen with your ‘infra-red barrier around a radiator.’

Vince Causey said in response to my comment:
“Surely, if temperatures are rising, (as posited by the GHG hypothesis) it must mean the exact opposite – namely that the Earth emits LESS energy that it receives. Therefore this is not a contravention of the laws of thermodynamics as you assert.”
No. Look at the Kiehl and Trenberth global energy flows diagram, for example. Earth receives 64wm2 (after deduction of thermals and evapotranspiration from insolation of 161 wm2) which somehow backradiation magnifies to an emission of 396wm2. This is more energy out than in.
Vince then says:
“There is nothing about a mechanism that radiates energy back to the Earth and resulting in a temperature increase that lends itself to the notion that this can in any way lead to free energy. If you try to drain energy from the atmosphere all that would happen is the atmosphere would cool down and the Earth would radiate faster and cool down more quickly. I suggest the same thing will happen with your ‘infra-red barrier around a radiator.’”
Well according to the radiation equilibrium theory, I could get a huge amount of energy with an infra-red barrier. But if that example does not impress you, how about a furnace with an infra-red barrier. A much cheaper way of melting steel. Why is it that nobody has patented this yet?

Tim Folkerts says:
March 1, 2011 at 5:55 am
Myrrh says: March 1, 2011 at 2:45 am
“Ira says that Visible is the largest part of the Sun’s spectrum, wrong, it’s actually the smallest, and compared with the others, very very small. Light is not hot, it is Reflective not Absorptive, and your use of “absorbed by matter of one form or the other” is misleading. The radiation that penetrates to heat the Earth is Thermal IR. And that is not in the Chart.”
The issue here is the “size of the energy”, not the wavelength. There is a handy table at http://en.wikipedia.org/wiki/Planck%27s_law that shows the energy distribution of sunlight (above the atmosphere).
* A little over 10% of the ENERGY is in ultraviolet photons or shorter wavelengths.
*Close to 40% of the ENERGY is visible light photons
*Over 40% is “near IR” (from 0.7-3um). (So Ira’s claim that visible is the biggest is not quite right, but it is not far off. On the other hand, the atmosphere is still mostly transparent to these wavelenghts, so his arguments still hold).
*Only a few % is above 3 um (“thermal IR”) so it cannot possibly be the main source for heating the earth.
It doesn’t show any such thing, missing bits. See http://ds9ssl.berkeley.edu/lws_gems/e/espec.htm
I think I’m going to start calling this AGWplanks law since its use has resulted in that Chart which made incoming Thermal IR from the Sun walk the plank out of our physical Earth and it’s now become practically impossible to find anything rational about this subject. Visible light is a tiny sliver of the electromagnetic spectrum, as you can see from the above link, it may be highly energetic, but it’s not the highest of that either.
Planck’s law “In physics, Planck’s law describes the spectral radiance of electromagnetic radiation at all wavelengths from a black body at temperature T. As a function of frequency v, Planck’s law is written as: …….Note also that the two functions have different units – the first is radiance per unit frequency interval while the second is radiance per unit wavelength interval.” http:www.worldlingo.com/ma/enwiki/en/Planck’s_law
All Planck’s law shows as graphs depict is that the hotter an object the higher the peak in Visible light. How does the Radiance peak here mean it has a greater AMOUNT of the ENERGY of that produced by a heated body?
That’s how steel workers can tell the temperature of steel they’re working on, from the degree of radiance as it goes into colour. It doesn’t mean anything else. It takes very hot to produce white light. The Sun’s heat certainly hot enough to produce white light.., but it’s a peak of radiance into Visible, it hasn’t stopped producing Thermal Infrared, nor has it stopped producing any of the other wavelengths which you haven’t included.
http://m.plantengineering.com/index.php?id=2831&tx_ttnews%5Btt_news%5D=33209&cHash=db4db9479b
“Not as widely recognized is the fact that incandescent objects emit a tremendous amount of invisible infrared radiation. For example, the radiance of a steel billet at 1500F is 100,000 times greater in the infrared spectrum than in the visible spectrum.”
The real “peak amount” then between the Visible and Thermal IR is not in the Visible. Planck’s peak frequency into visible does not equal peak amount given off by a heated object.
A bog standard lightbulb gives 95% of its energy in Heat, which is Thermal Infrared (Near Infrared included in “Solar”, is not hot, it’s a cold light.) If you drew a graph showing this relationship, where would the peak be?
……………………………………..
izen says:
March 1, 2011 at 6:45 am
Re: the same quote of mine, above.
The vast majority of the energy direct from the Sun that heats the Earth is in the visible spectrum, NOT the IR. If you doubt that visible light can heat things consider the car on a sunny day. The glass of the windows blocks IR but lets through visible light that is absorbed by the (usually) dark plastic/leather interior. The hot steering wheel and seat are warmed by the visible light not any IR.
Glass does not block IR. Visible light is REFLECTIVE. It bounces off things. IR is ABSORPTIVE in organic stuff, the car is absorbing IR Heat all over.
You are correct of course that the surface is ALSO heated by the 7um and 15um IR emissions from the H2O and CO2 in the atmosphere that has been warmed by the IR emissions from the surface..
Well you have to say that don’t you, because you’re following AGWScience which can make up any number of impossible things for you to believe before breakfast. The heat we feel from the Sun, DIRECTLY, is Thermal IR. Regardless of whatever else amount is coming to us, from the heated things around us for example, to exclude this direct Thermal IR from the Sun is just plain ludicrous. I’m finding it impossible to phrase it any other way.
…………………………………………..
Ira Glickstein, PhD says:
March 1, 2011 at 6:11 am
Re: Myrrh says: I’m really at a loss to understand any of this. How on earth does Visible light and near short wave heat the Earth?
Myrrh, you really need to get outside more and sit in the Sunshine and feel the warmth! That is how visible and near-visible (“shortwave”) light warms the Earth.
If you don’t or cannot get outside, turn on an old-fashioned incandescent light bulb and hold your hand near it (not too close you will get burned). Feel the heat? That is shortwave light because the filament is heated to temperatures similar to the Sun’s surface. You can tell it is shortwave because you can see the light.
Well, again with the intellectual disdain from the so-calling themselves experts..
Ira, please take note of my replies above. I am determined to get to the bottom of this because this is a KEY premise on which AGW energy is based and all other energy arguments depend, and it’s simply nonsense.
For lightbulb information – http://www.newton.dep.anl.gov/askasci/eng99/eng99505.htm
& especially:
Physics 101: http://science.hq.nasa.gov/kids/imagers/ems/infrared.html
“Infrared light lies between the visible and microwave portions of the electromagentic spectrum. …The longer, far infrared wavelengths are about the size of a pin head and the shorter, near infrared ones are the size of cells, or are microscopic.
Far infrared waves are thermal. In other words, we experience this type of infrared radiation every day in the form of heat! The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared. The temperature-sensitive nerve endings in our skin can detect the difference between inside body temperature and outside skin temperature.
Shorter, near infrared waves are not hot at all – in fact you canot even feel them. These shorter wavelengths are the ones used by your TV’s remote control.”
So, WE CANNOT FEEL VISIBLE LIGHT – it is not hot. It does not carry HEAT. The Radiation we feel from the direct from the Sun which is HOT, is Thermal IR.
You have excluded this in your Chart. We can all feel you’re wrong to do so..
This AGW premise defies REAL Science, it is already FALSIFIED. Nothing that AGW calculates thereafter from this premise has any credibility whatsoever.
Has it?
Now, as I said, I’m finding it really difficult to find anything discussing this sensibly at all, most of what’s on line has been so thoroughly trashed by AGWScience propaganda in its utter mangling of basic science concepts. Here it is attributing to Visible light and near neighbours (Solar of AGW), that which is rightly only applicable to Thermal IR.
But, I did find this just now: http://ishangobones.com/?p=509
Which appears to be explaining the actual process I’ve been thinking of as Reflective v Absorptive.
Thermal IR’s absorption method I’ve seen described as Conversion in those areas which deal with its absorptive energies, capacities, spectroscopy, medical and such, (as in a heat pad delivering Thermal IR to aching muscles, etc.), but I wasn’t concentrating on it, and I seem to recall a description similar to what’s being said here. Encyclopedia of planetary sciences says “Absorption is the conversion of electromagnetic energy to another form of energy through interaction with matter. The process can be viewed at several levels, but the end result is usually heat.”
Anyway, Thermal IR is absorptive and Visible and Near IR are not, but are reflective in all general descriptions of the difference.

George E. Smith says:
March 1, 2011 at 2:08 pm
Thanks for the further explanation between cold/hot and thick/thin gases. The Rutgers statement of Kirchoff’s First Law of Radiation was not clear about the distinction and I thought further clarification would probably be needed.
Cold dense gases emit a continuous blackbody spectrum characteristic of their temperature. “Cold” means below the ionization energy threshold. “Thin” is a little more ambiguous but your description was good i.e. thin enough so that collisions are rare. In the earth’s atmosphere “thin” would begin beyond the mesopause at 90 kilometers where the temperature starts increasing with altitude and can rise to thousands of degrees F.

Tim Folkerts says:
March 1, 2011 at 2:38 pm
“For 400 ppm it clearly takes less than the height of the atmosphere, but how much less?”
APPROXIMATELY 12,000 FEET OVER THE ARCTIC OCEAN. SEE THE GRAPH OF IR SPECTRUM FROM 20,000 FEET LOOKING DOWN THAT IRA POSTED IN THE COMMENTS TODAY.
IN THE IR WINDOW YOU SEE A 265K BLACKBODY CURVE. IN THE 15UM CO2 ABSORPTION WINDOW YOU SEE A 225K BLACKBODY CURVE. THIS IS A TEMPERATURE DROP OF 40K. DRY ADIABATIC LAPSE RATE IS 1K PER 100 METERS SO THE POINT WHERE THE SPECTROMETER NO LONGER INDICATES ANY 15UM ABSORPTION IS 4000 METERS.
THIS WILL VARY SOMEWHAT DEPENDING ON THE TEMPERATURE AND ALTITUDE OF THE SURFACE. AT HIGHER SURFACE ALTITUDES THERE IS LESS TOTAL CO2 IN THE COLUMN ABOVE IT AND IT WILL TAKE MORE THAN 12,000 FEET OF AIR TO GIT ‘ER DONE. THE TEMPERATURE OF THE SURFACE WILL SHIFT THE PEAK SURFACE EMISSION FREQUENCY AWAY OR TOWARDS 15UM WHICH MEANS LESS OR MORE, RESPECTIVELY, 15UM ENERGY TO ABSORB.

Al Tekhasski says:
March 1, 2011 at 12:01 am
“I am sorry, but for the sake of accuracy, CO2 in air does not have any states that interact with 10-13um band. Therefore, hot air cannot possibly generate any photons in that range. Therefore the following statement is also wrong, nothing gets “transferred” into 10-um band from “heated air”:”
I AM SORRY BUT YOU ARE WRONG. COLD DENSE GASSES ALL EMIT A CONTINUOUS BLACKBODY SPECTRUM. SEE KIRCHOFF’S FIRST LAW OF RADIATION WHICH I POSTED EARLIER.

As it “re-radiates” in all directions, then it also must be said that it speeds up how fast the surface cools. Right?

George E. Smith,
“Did the classical EM radiation laws of Maxwell not run up against the ultraviolet catastrophe and hence the modification by Planck and Einstein introducing the quantised photon?”
One of the misconceptions that even good scientists fall prey to is believing that mathematics drive science. Mathematics is a tool that can be used to DESCRIBE the real world and allow us to manipulate ideas about it and make projections if we do a good enough job of the description.
I can draw a picture of something and easily transfer a number of data points to tohers through a picture with absolutely no understanding by wither of us of what we are seeing. Mathematics can do the same for the real world in physics.
Sadly climate science has latched onto a few data points and algorithms and think it covers EVERYTHING while still struggling with how poorly their models do. At a much higher level quantum physicists do the same. It really is all RELATIVE!!
HAHAHAHAHAHAHAHAHAHAHAHA

Ira, I mostly praise the way you presented this post, much clearer, but the only thing I will complain about of you post is in this statement:

However, they differ in the mechanism. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because “greenhouse gases”
(GHG) absorb outgoing radiative energy and re-emit some of it back towards Earth.

There you need to lose the statement “heats the Earth”. That is nonsense. You might say “keeps Earth warmer that without” or “slows the cooling of the Earth”, both implying the action of an insulator, but anything but what you said.
For myself, I have now move on the scale from ‘warmist’ to ‘skeptic’ and now just a tad before ‘denier’ so I think both of those statements are also most likely incorrect, but still that’s a better way for you to state it. It’s just that “warms the Earth” breaks core thermodynamic principles and it unqualifiedly wrong. Best to admit it and restate.
But I know you’ve already gotten an earful on that same matter.

http://wiki.answers.com/Q/What_percentage_of_the_electromagnetic_spectrum_is_visible_light
some answers..

Wayne wrote:
“So you are saying that if you had a large clump of warm nitrogen in empty space held together by gravity that it could not radiate in a black body manner at all, zero, none, zip? Maybe check some good astronomy books on that matter that cover quantum aspects.”
and
“Ira placed no numbers on exactly how much was split between those 7, 10, and 15 µm band portions. Just that those interactions do occur.” … That is how I see it from my years in studying physics.”
Wayne, maybe you need to continue study physics for some more years and learn how to put numbers on magnitude of effects. I am sure you heard about “pressure broadening” and “collision-induced absorption” during your studies. Now consider that we are not living on a star. Please open your reference book and compare gas pressures and temperatures of stars with Earth atmosphere.
Then try to comprehend the the difference between numbers. It is called “Physics”.
Please also do understand that “greenhouse effect” does not occur because 1/1,000,000 fraction of 15um band energy gets re-distributed and re-emitted from 10-13um band.
But of course you are formally correct. Instead of saying “hot air cannot possibly generate any photons in that range” I should have said “hot air cannot generate any remotely considerable amount of photons in that range”.