What upset the hysterics was that the prior analysis of almost 100,000 air samples with a variety of document factors like location, temperature on the sample date, etc., showed substantial variation in CO2 concentration and that variation was correlated with sea temperatures. Think about that, because the same issue shows up in ice cores. It appears that temperature changes lead, and are likely a very strong causative factor in CO2 levels, making it unlikely that fossil fuel emissions are actually doing much to affect temperature. In particular between 1939 and 1943 the CO2 level spiked to something close to today’s level. The researcher demonstrates that there was nothing flukey about this, that it was real and linked to real physical processes including increased soil respiration of CO2 and the aforementioned higher sea surface temps which also lead to more CO2 outgassing.

You look at the charts in this paper and it is pretty clear, given the sensitivities of release of CO2 from the soil and water, that temperature changes are the primary cause of increases in CO2. Just a small temperature change leads to a very large increase in such releases. This is deadly to the hysterics, absolutely deadly, which is why the paper, which is peer-reviewed and written by an established climate scientist, has gotten so little attention.