I really don’t understand the “CO2 causing stratospheric cooling” thing.
I mean I get the basic idea that CO2 mostly heats up the troposphere, and as a result there is less IR to go into the stratosphere and above, causing those layers to cool. But some of the details don’t make sense. From this website (the only source that RC gives to explain it):
...carbon dioxide emits heat radiation, which is lost from the stratosphere into space. In the stratosphere, this emission of heat becomes larger than the energy received from below by absorption and, as a result, there is a net energy loss from the stratosphere and a resulting cooling.
Can someone explain how the bolded part doesn't violate the laws of physics?
And this claim does agree with another, equally confusing claim I’ve heard a few times, that is (if I understood it right) something to the effect of: “CO2 in the upper atmosphere acts as a radiator for heat, accelerating the heat loss to space and thus causing cooling.”
Wouldn’t the fact that the direction of emission is random (360 degrees) mean that CO2 is just as effective at warming the stratosphere as it is the troposphere? (The fact that concentrations are lower and there is less IR aside...how does what is left not do the same thing as what happens in the troposphere?)
Can anyone tell me where I'm confusing myself on this one?
Edited by dawei - 4/2/2009 at 05:05 am