128 years ago

In 1896, scientists determined that industrialization was adding CO2 to the atmosphere and quantified how much it would warm the Earth. That date is closer to the start of the Industrial Revolution than to the present day.

https://xkcd.com/2889/

If you’re wondering, like I did, about that 1896 date — what about Fourier and Pouillet and Tyndall and Eunice Foote?

https://en.wikipedia.org/wiki/Greenhouse_effect#History_of_discovery_and_investigation

https://en.wikipedia.org/wiki/History_of_climate_change_science#First_calculations_of_greenhouse_effect,_1896