Solar Output Not CO2 Drives the Climate.

[Crick]

But Billy Boy, we weren't asking what happens when it absorbs and RELEASES a photon. We just wanted to know what happens when it absorbs some. Do you agree with jc that NOTHING happens? Is that what your remedial science instructor tells you?

Let me add that if you think nothing happens, you're going to have some difficulty explaining how it is able to emit the photon you tried to slip in there. There are energy barriers to be overcome. JC's suggestion would be a violation of the conservation of energy.

So what is it boy? What happens to CO2 that absorbs IR radiation?

 

[IanC]

It seems like most of you guys don't have a clue about basic physics.

Do you even know where radiation comes from? If you bang two particles together the total energy is combined, afterwards the resultant speeds are less by the exact amount of energy as the photon(s) produced in the collision. This is why things radiate and cool off.

In the special case of GHGs, certain bands of radiation are absorbed and the molecule has increased energy (but not increased speed/temperature). If this excited molecule collides it brings more energy to the total and either produces more speed or more radiation. If the excited molecule simply re-emits the photon before a collision happens then no change occurs except for the momentum exchanged which will on average spread the distance between the emitting source and the absorbing/re-emitting molecule (entropy).