T8 wrote:

Most of the IR absorption spectrum of CO2 is so strong that at these
wavelengths, the little CO2 in the atmosphere is optically dense, and
increasing (or decreasing) its concentration has only tertiary and
probably unmeasurable effects on climate. There are weaker absorption
bands that may make a difference, but some/most(?) of these are in
areas of the spectrum where water vapor dominates completely as long
as water vapor is present.

-Evan Ludeman / T8

I have tried to make that point over a year ago, having worked
in the IR surveillance field for 20 years and found you can't
shake the "true believers" faith with facts. :-(
...lew...