@metal-brain said
http://www.biocab.org/Overlapping_Absorption_Bands.pdf
I had a look at their site. The first thing I noticed is that there is no indication that any of them have any qualifications. The guy describes himself as a professor, but that is an academic post and not a qualification. The paper is badly written, there's a form to writing these things which you can see an example of here [1], note this is Ed Witten on particle physics - I'm not expecting you to read it, just note that this is what a paper should look like.
Regarding the actual content, he's relying on a book [2] which I assume is authoritative, but it is really unclear whether he's applied the equations he's snatched from it correctly.
Now let us proceed to calculate the magnitude of the overlapped radiative emissionbands of the water vapor and the carbon dioxide. To do this, we apply the following formula:
With no indication of where the formula comes from and why it is relevant, not even a page number. He then writes this conclusion:
The emissivity of the water vapor decreased by 0.0872 units.
He really ought to have been able to work out the units, or better still quote them as a percentage. Atmospheric physics isn't my thing, but the calculation is for conditions at 1m height and the conclusion might be different at 50,000ft. It is not obvious why this calculation is relevant. The people who produce global climate models take some care in including effects and might be expected to have thought of this particular effect anyway. There is no indication in the paper that he's investigated their absence. I don't regard this paper as being evidence.
[1] https://arxiv.org/pdf/1907.03363.pdf
[2] Modest, Michael F.;
Radiative Heat Transfer; Second Edition 2003. Elsevier Science, USA and Academic Press, UK.