where do you get you figures to assert that just 0.04% of the atmosphere can absorb every ir photon? Even if it were possible, a warming atmosphere would produce more water vapour in clouds causing cooling of atmosphere once again- As well ‘back radiation’ has been pretty well dismissed by scientists
[[Doomsaying Climatologist Abandons ‘Back Radiation’ Meme
Only recently did Professor Claes Johnson persuade long-time greenhouse gas effect believer Dr. Judith Curry to abandon this unscientific term. Curry now admits:
“Back radiation is a phrase, one that I don’t use myself, and it is not a word that is used in technical radiative transfer studies. Lets lose the back radiation terminology, we all agree on that.”
IPCC doomsayers claim it is under this “blanket” of CO2 (and other so-called greenhouse gases) that the energy absorbed by Earth’s surface from incoming sunlight gets trapped.
But one other important fact often glossed over is that CO2 comprises a tiny 0.4% of all the gases above our heads. Nasif Nahle reminds us that this is a crucial point when considering the claims of the “grandfather” of the greenhouse gas hypothesis (GHE), Svente Arrhenius.]]
And, CO2 rises rapidly when denser, traps a small amount of heat, then cools again rapidly
[[CO2: The Heavy Gas that Heats then Cools Faster!
The same principle is applied to heat transfer, the Specific Heat (SH) of air is 1.0 and the SH of CO2 is 0.8 (heats and cools faster). Combining these properties allows for thermal mixing. Heavy CO2 warms faster and rises, as in a hot air balloon. It then rapidly cools and falls.]]
(same link)
and again, where is the evidence that the insiginificant amount of CO2 at just 0.04% can trap all the heat, then make it hotter, and radiate it back to earth in quantities hot enough and large enough to cause warming on a global scale?
Every IR photon with the right wavelength to be absorbed (I forgot that caveat). There are something like 10^25 molecules in a cubic meter of air or 10^22 CO2 molecules. That is more than enough for absorption saturation. But of course those molecules also radiate in all directions including out to space. So each layer of the atmosphere also cools more as it gets warmer.
Even if it were possible, a warming atmosphere would produce more water vapour in clouds causing cooling of atmosphere once again
If the surface is wet. That's the reason the southern hemisphere has warmed a lot less than the northern overall.
But one other important fact often glossed over is that CO2 comprises a tiny 0.4% of all the gases above our heads
From above, 10^22 molecules of CO2 per cubic meter cannot be ignored.
Please don't point to Postma and other junk as "debunking" the greenhouse effect. Basically Postma is attempting to "prove" through his equations that the surface warmth can be explained without GHE. But he makes several mistakes and the alternative, that GHE is required to reach current average temperature, is accepted science. There are many threads at Curry's and other places explaining this: http://judithcurry.com/2011/08/16/postma-on-the-greenhouse-effect/ Suggesting that Curry has abandoned the GHE effect just because she doesn't like the phrase "back radiation" is incorrect. All sides in that "debate" agree that the atmosphere absorbs some IR. The only actual disagreement is whether back radiation is a "real" transfer of energy via IR photons or not. But if the CO2 in the atmosphere absorbs IR, it also radiates IR in all directions.