I’d have more credibility in his findings if he had said that “fairy dust” combined with the CO2 had warmed us for 11,000 years.
The total amount of CO2 in the earth’s atmosphere today is something like a measly 0.038%. And that includes the NATURALLY occuring variety. Moreover, the single most powerful gas in the greenhouse system, by far, is water vapor, nearly all of which is of natural origins. Something like 97% of the GH effect on earth is due to water vapor.