Response to a paper by Hermann Harde, from Ken Rice at … And Then There’s Physics.

Dr Rice cites two other responses as well:

• One by Gavin Schmidt at RealClimate.
• One from 2011 by Gavin Cawley from the University of East Anglia

I’ll add one of my own. Eli Rabett addressed Harde’s claims backin 2011. Moreover, Professor Ray Pierrehumbert himself posted a comment there regarding Harde’s work, on 3 May 2011, saying:

As David Benson kindly explains, all is explained in Chapter 4 of Principles of Planetary climate. I’ll also add (for people who want the 6-page version) that my Physics Today article is all the refutation Harde needs. The fact that the AIRS observed spectra of Earth’s outgoing radiation exactly matches the computation done by the line-by-line code (which in turn validates the band-averaged codes used in GCMs) makes it impossible that Harde’s calculation can be right. If he thinks he has a case, he has to show that he can reproduce the AIRS spectra — also the similar CO2 features one sees in the Mars TES observations, etc.
…
–raypierre

The Harde paper and work confuse what you’d see if you were riding on a particular CO₂ molecule with what’s the average CO₂ concentration in atmosphere and other reservoirs. One might go out of atmosphere to a reservoir, but there’s another from that or another reservoir to take its place. It makes several other mistakes as Drs Rice and Schmidt indicate. Can’t get a handle on any of this without looking at the entire Carbon Cycle. Harde has a picture of the reservoirs in his paper, but makes a mistake in his equation “(8).” I don’t think he cares. His major point is to rebutt IPCC assertions, not illuminate science. The IPCC does not do original science. Harde’s criticisms should have been directed at the original works from which these IPCC presentations were derived. Had he done so, his paper would probably not have been accepted, because those original works have long been accepted and used. We’ll see what happens with his paper in the sequel, but it’s somewhat of a mystery how this stuff gets out there, or why. (Well, maybe the why is not so difficult to understand …)

The above is a reproduction of Figure 3 from C. Le Quéré, et al, “Global Carbon Budget 2016,” Earth Syst. Sci. Data, 8, 605–649, 2016.

This kind of thing is why, unfortunately or not, the general public cannot be expected to understand these questions without a good grounding in science and what are, perhaps, the less popular fields, like physics and some maths. The courtroom or Congressional committee techniques of stacking up supposed experts does not work here^(*).

^(*) Actually, some statisticians have found courtrooms to be wanting as means of ascertaining truth, too.