“Carbon dioxide () is one of the greenhouse gases. It consists of one carbon atom with an oxygen atom bonded to each side. When its atoms are bonded tightly together, the carbon dioxide molecule can absorb infrared radiation and the molecule starts to vibrate. Eventually, the vibrating molecule will emit the radiation again, and it will likely be absorbed by yet another greenhouse gas molecule. This absorption-emission-absorption cycle serves to keep the heat near the surface, effectively insulating the surface from the cold of space”- ucar.edu
The claim has been made that the CO2 molecule immediately reemits the photon so any warming is quite minor. I am of the opinion ucar has it correct above. CO2 holds onto the infrared radiation long enough on average to warm.
Animation of a CO2 molecule here:
“Molecules of carbon dioxide (CO2) can absorb energy from infrared (IR) radiation. This animation shows a molecule of CO2 absorbing an incoming infrared photon (yellow arrows). The energy from the photon causes the CO2 molecule to vibrate. Shortly thereafter, the molecule gives up this extra energy by emitting another infrared photon. Once the extra energy has been removed by the emitted photon, the carbon dioxide stops vibrating – ucar.edu
Ucar says some things above. It does keep the heat near the surface and the CO2 molecule holds the photon for a short time and also uses the phrase, “Eventually, the vibrating molecule will emit the radiation again”. What about water vapor? I think of water and water vapor as an ideal heat storage medium. It absorbs well enough and holds well enough to have many uses for us and the planet. Soil also absorbs, and stores heat. We don’t see instant re-emission with these.
Ira Glickstein writes:
“This frame and the next two illustrate another way Photons are emitted, namely due to collisions between energized GHG molecules and other air molecules.”
It is implied that they hang onto the photon long enough to interact with their neighbors, and that the collisions transfer heat.
I’d like some scientists who work in the area to clarify the situation for the rest of us, and I am still thinking the instant re-emission argument will not hold up.
There is also this:
The Random Walk Problem. Even at the speed of light there’s a delay.