On this day, October 2nd 1927, Swedish scientist and Nobel Prize winner Svante Arrhenius died.
The guy who did the back of envelope calculations (big envelope, it took him a year).
The atmospheric c02 level was 305ppm. It is now about 421ppm.
See also “Megascience” thing from Ambio
From Arrhenius to megascience: interplay between science and public decision making https://www.jstor.org/stable/pdf/4314553.pdf
By coincidence, exactly 37 years later, British scientists and engineer Guy Callendar died. (See here).
On Callendar, James Fleming has done excellent work (link).
[The amount of carbon dioxide in the atmosphere was 316.87ppm. At time of writing it was 421ish ppm – but for what it is now,well, see here for the latest.]