physics.jamesbaugh.com/co2saturation.html
CO2 has very little, if anything, to do with it.
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Ah, the old saturation myth again! If you look at the graph on which Mr. Baugh bases his conclusion, you will see that it does not support his claim. He claims that CO2 absorption is already saturated, and that adding more CO2 cannot capture more heat.
But here is where his argument falls apart. The graph shows solar irradiance as received on the surface, complete with dips associated with CO2 absorption. And the very bottom of those dips do indeed get very close to 100% absorption. But that is at only one wavelength. In the wavelengths along side the bottom of each dip, the total absorption is substantially less than 100%, going all the way up to 0% when you get far enough away from the center of the dip. The total IR energy that gets through the entire atmosphere in the vicinity of an absorption band is the integral of the irradiance over wavelength. If you double the CO2 concentration, those nearby slopes of the dip will get twice as close to 100%. There is certainly room for more energy to be absorbed with more CO2.
Also the graph shows the effect of the entire column of atmosphere - from the surface up to the stratosphere. Even if there was nearly 100% absorption at a given frequency, that would not support Mr. Baugh’s contention that 99% of the energy is absorbed in 10 meters of atmosphere.
Finally, there is the issue of where the energy gets absorbed. Even if there is saturation, the CO2 always re-radiates the energy in all directions after it has been absorbed. If that re-radiation takes place near to the surface, there is a whole lot more CO2 above than below, so the chances of that energy escaping into space are extremely low, compared to the chances of that energy hitting the surface and warming it up. However, if that re-radiation takes place up near the top of the atmosphere, it has a much better chance of escaping to space, because there is so little CO2 left between the point of re-radiaiton and the depths of space.
So even if there were 100% absorption, it matters
where the absorption takes place. And now we must remember that the greenhouse effect does not work by absorbing IR energy from sunlight. It works by absorbing black body radiation from the surface. So with a higher concentration of CO2, more absorption will take place closer to the surface, where the air temperature is warmer to begin with, and where the chances are that re-radiated energy will not escape to space.
So you see that it is easy to take a little bit of science and twist it to make it sound like the CO2 greenhouse effect is saturated. The funny thing is, others who also don’t accept global warming, have based their conclusion on their belief that there is** too little CO2** to have any effect at all! Isn’t global warming skepticism great? Global warming is a hoax because there is too little CO2, or because there is already too much CO2. Take your pick. You win either way!