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Post by julianb on Mar 26, 2009 11:01:41 GMT
No Steve the graph isn't wrong, it's a hat ;D
Turn it upside down, add another layer, and the escaping heat is tranferred at a new wavelength to the adjoining curves ! Hat No6, and it won't keep you much warmer.
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Post by steve on Mar 26, 2009 13:28:22 GMT
No Steve the graph isn't wrong, it's a hat ;D Turn it upside down, add another layer, and the escaping heat is tranferred at a new wavelength to the adjoining curves ! Hat No6, and it won't keep you much warmer. So it will keep you a bit warmer. That's agreed then
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Post by kenfeldman on Mar 26, 2009 16:25:20 GMT
No, no, a thousand times no! CO2 and other greenhouse gases only stop a portion of the energy going into space and re-radiate a fraction of that portion back down toward the surface. However, it's enough to warm the planet by 33 degrees. Here's a scematic diagram of the energy flows in the climate: And here's a paper to read on energy flows in the climate system: ams.allenpress.com/archive/1520-0477/preprint/2008/pdf/10.1175_2008BAMS2634.1.pdf
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Post by jimg on Mar 26, 2009 16:49:01 GMT
Cute picture, but that's all it is.
There is no possible way to accurately quantify all of the forcings. Thus assumptions are made and incorporated into the models.
The assumptions keep getting "adjusted" until the model looks like the "current" weather picture. When the "weather" changes, the models get tweaked again.
The picture also shows a balanced energy flow. In=out. For temp to rise or fall requires an inbalance.
The old GIGO principle.
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Post by kenfeldman on Mar 26, 2009 17:19:46 GMT
Actually, there is. Scientists go into the field and take measurements on the ground and at sea, and with airplanes and weather balloons, in the atmosphere. Satellites take measurements at the top of atmosphere.
It's spelled out in the paper that I included in my previous post.
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Post by steve on Mar 26, 2009 17:20:51 GMT
I agree that the diagram is oversimplified because the enhanced greenhouse is a function of the profile of the atmosphere, and the diagram doesn't represent the profile of the atmosphere.
That's why I put this question to Poitsplace:
Essentially, what you are claiming is that the earth emits into space no radiation in the wavebands absorbed by CO2, because it has all been absorbed by the CO2. Do you believe that?
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Post by icefisher on Mar 26, 2009 18:02:40 GMT
Cute picture, but that's all it is. There is no possible way to accurately quantify all of the forcings. Thus assumptions are made and incorporated into the models. The assumptions keep getting "adjusted" until the model looks like the "current" weather picture. When the "weather" changes, the models get tweaked again. The picture also shows a balanced energy flow. In=out. For temp to rise or fall requires an inbalance. The old GIGO principle. Yep that cloud in the middle of the atmospheric absorption band in Kens graph. Nobody realistically claims to have any understanding of that. Since clouds are most affected by those evapo/transpiration cycle this figure becomes the "plug" number to get whatever result they want at the moment. And that back radiation number. . . .isn't that a violation of the 2nd law of thermodynamics? Just askin!
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Post by poitsplace on Mar 26, 2009 21:32:27 GMT
I agree that the diagram is oversimplified because the enhanced greenhouse is a function of the profile of the atmosphere, and the diagram doesn't represent the profile of the atmosphere. That's why I put this question to Poitsplace: Essentially, what you are claiming is that the earth emits into space no radiation in the wavebands absorbed by CO2, because it has all been absorbed by the CO2. Do you believe that? No, I'm pointing out that because CO2 is stopping most of it's frequencies already...increasing it doesn't have the same affect. The system is already offloading MOST of the energy that CO2 absorbs. A great deal of the energy you seem to think is getting tied up in CO2...isn't.
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Post by glc on Mar 27, 2009 0:53:37 GMT
No, I'm pointing out that because CO2 is stopping most of it's frequencies already...increasing it doesn't have the same affect. The system is already offloading MOST of the energy that CO2 absorbs. A great deal of the energy you seem to think is getting tied up in CO2...isn't It is (or can) at higher levels of the atmosphere where CO2 dominates (i.e. very little water vapour) and where, because it's colder, it cannot emit the necessary ~240 w/m2 to balance the incoming solar energy - so the atmosphere must warm until ~240 w/m2 is emitted. I've posted something similar on about 5 previous occasions. I'm not sure how many more different ways I can express it but here it is again: The key point of AGW theory relates to what happens at the "top of the atmosphere".
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Post by magellan on Mar 27, 2009 0:56:08 GMT
No, I'm pointing out that because CO2 is stopping most of it's frequencies already...increasing it doesn't have the same affect. The system is already offloading MOST of the energy that CO2 absorbs. A great deal of the energy you seem to think is getting tied up in CO2...isn't It is (or can) at higher levels of the atmosphere where CO2 dominates (i.e. very little water vapour) and where, because it's colder, it cannot emit the necessary ~240 w/m2 to balance the incoming solar energy - so the atmosphere must warm until ~240 w/m2 is emitted. I've posted something similar on about 5 previous occasions. I'm not sure how many more different ways I can express it but here it is again: The key point of AGW theory relates to what happens at the "top of the atmosphere". And you are wrong if you think the hypothesis is tested and not failed.
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Post by kiwistonewall on Mar 27, 2009 3:23:36 GMT
Warning: Cat amongst the pigeons:
As I posted on the main global cooling thread, I want to point out (politely) that the entire atmosphere absorbs IR and radiates IR.
Gases are not immune from the laws of thermodynamics and absorb & emit IR radiation. At the same temperature as the Earth surface, their emission signature is identical. The only thing different about "greenhouse gases" - a misnomer btw! - is that they can absorb and emit outside the blackbody curve. This effects the base blackbody signature, but doesn't upset the laws of thermodynamics.
Thus the WHOLE atmosphere participates in the greenhouse effect, allowing heat to move upwards in thermal equilibrium. ZERO heat can move back to the warmer earth surface (forbidden by the 2nd law of thermodynamics).
In reality, a huge amount of latent heat is moved from the earth via water vapour to the atmosphere, where it condenses as heat, warming the atmosphere. Anytime the atmosphere is warmer than the surface, there will be a net thermal radiation back to the earth, being the difference between the two blackbody curves.
I'm not saying that CO2 cannot have an effect. I'm saying that the classic greenhouse effect explanation is nonsense. Any blackbody radiation passing through molecules that absorb certain frequencies will absorb & re-emit. But any thermal, heat transfer, always, must, has to, obey the laws of thermodynamics.
Main points:
* All matter emits blackbody radiation (unless modified by surface issues - which don't effect gases - gases are close to true bb radiators)
* The atmosphere delays the transfer of IR radiation from the Earth's surface - this happens across the entire spectrum.
* "Green house gases" can have no thermodynamic effect - all equations depend on Temperature, NOT the concentration of any GHG.
Conclusion: form your own.
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Post by poitsplace on Mar 27, 2009 3:43:19 GMT
No, I'm pointing out that because CO2 is stopping most of it's frequencies already...increasing it doesn't have the same affect. The system is already offloading MOST of the energy that CO2 absorbs. A great deal of the energy you seem to think is getting tied up in CO2...isn't It is (or can) at higher levels of the atmosphere where CO2 dominates (i.e. very little water vapour) and where, because it's colder, it cannot emit the necessary ~240 w/m2 to balance the incoming solar energy - so the atmosphere must warm until ~240 w/m2 is emitted. I've posted something similar on about 5 previous occasions. I'm not sure how many more different ways I can express it but here it is again: The key point of AGW theory relates to what happens at the "top of the atmosphere". Which makes the missing temperature changes within the atmosphere that much more important. If those changes aren't happening then an interaction we don't know about is snatching the energy away from CO2 and emitting outside of its spectrum. Hmmm, I wonder if there's any sort of gas available across the surface of the earth...that overlaps most of CO2's spectrum but also has strong interaction at other frequencies outside CO2's spectrum. Ideally it would be one that decreases significantly faster than normal ideal gas laws that normally govern densities as we lower pressure. Hmmm...what ever could do such a thing? I have to say, I'm stumped. I think I'm going to go to the water fountain and get a quick drink. Maybe I'll luck out and the answer will jump out at me.
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Post by kiwistonewall on Mar 27, 2009 4:09:03 GMT
" If those changes aren't happening then an interaction we don't know about is snatching the energy away from CO2 and emitting outside of its spectrum. " Exactly - as I have already posted on the main thread. The IR energy absorbed by CO2 is passed to the more abundant water molecules - which is why the IR signature of tropical Earth has a dip for CO2 and broad peaks for water. Over all, CO2 has NO EFFECT. (Boy, am I asking for a flaming). Thermodynamics rules and radiation is a function of T, f(T) NOT a function of CO2 f([CO2])
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Post by crakar24 on Mar 27, 2009 4:26:44 GMT
In regards to Kens diagram i have a couple questions;
Firstly if the earth is in balance as the diagram shows then the earth will neither warm nor cool is this correct?
So if we add extra CO2 then more IR gets trapped and the earth will warm, correct?
The same goes for if CO2 reduces then less IR gets trapped and the earth cools, correct?
If so then why as CO2 levels have increased the global temp has not followed this CO2 increase? What part of the diagram do we use to explain this?
Also if this diagram and the explanation to go with it are correct this AGW scenario would have occurred many years ago starting with the appearence of the first molecule of CO2.
This lone molecule would have trapped some heat cuasing the Earth and oceans to warm giving off more CO2 molecules which trap more heat releasing more CO2 and so on.
Does this make sense or is my logic flawed? If so could you please explain where i have gone wrong.
Cheers
Crakar
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Post by jimg on Mar 27, 2009 5:52:18 GMT
Two questions: for Kenfeldman * glc Kenfeldman: 342w/m^2 in and out. Where does that number come from? TSI is ~1361w/m^2. lasp.colorado.edu/sorce/total_solar_irradiance_plots/images/tim_level3_tsi_24hour_640x480.pngglc: The key point of AGW theory relates to what happens at the "top of the atmosphere". As I understand what you are saying... As CO2 absorbs IR, it will excite that molecule, increasing its ave kinetic energy (ie Temperature). This will cause the upper atmosphere to warm. As a gas, warmer gases expande to the confines of their container. In this case, those bounds are defined by gravity and their temperature. So, if the upper atmosphere is getting warmer, why has it shrunk by 100+ km?
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