Here is the absorbtion spectrum of CO2 : https://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Type=IR-SPEC&Index=1#IR-SPEC As you can see, it has low transmittance a little over 4um wavelength and between 14-16um
Compare that to the blackbody spectrum at 300K (27C, or 80F in freedom units) https://phet.colorado.edu/sims/html/blackbody-spectrum/latest/blackbody-spectrum_en.html
The emission of blackbody radiation starts at a little below 4um, peaks at 9.8um, then continues with significant emission to above 20um. so the absorbsion of the CO2 is within the ground emission spectrum.
The sun emits radiation at 5600K, much shorter wavelenght which are not absorbed by CO2, those radiation hit the ground, heat it, and the ground emits black body radiation at around 300K. that longer wavelength radiation leaves the ground. As that radiation goes up, the part of it that is within CO2 absorbtion spectrum can get absorbed. When a CO2 molecule absorbs a photon, one if it's electron gets bumped to a higher energy level, then one of two things can happen : A) the electron goes back to it's original energy level, emitting another photon in a random direction, or B) the CO2 molecule hits another molecule and the excited electron gives back it's energy to the other molecule as kinetic energy (I.E. heat). A is much more likely to happen in gases, while B is more likely in solids/liquids.
when A happens, it does not really heat the atmosphere, but it impedes the ground heat dissipation in the wavelenghts where there is high absorbtion. So if we are to keep the energy balance, what happens to the ground ? It has to increase temperature to dissipate more heat in the wavelengths that are not affected by CO2.
All of that stuff was figured out long ago in the 1800s, it's pretty baffling that people can deny it 200 years later. But I don't lose sleep over it, I took the doom pill over climate change long ago. We're fucked. even if we could magically convince everybody that we ought to do something about it, it would require a level of international cooperation that I think is impossible. How do you make all the world powers sit around a table and agree on a "let's all get poor until we figure out better energy sources" program when they can't agree on much smaller things.
and as for experimental measurement of CO2 radiative forcing, I found this paper : https://sci-hub.se/10.1038/nature14240
I see it more as a dead give-away of the usual incompetence of governements. Would you argue that governements are not interested in heatlhcare and education ? Yet they manage to do stupid things in both domains. the same is true for the environnement.
More options
Context Copy link