And 115 years later, Stephen Hawking was parroting the same nonsense.
Arrhenius made a fundamental error in that he didn’t recognize H2O is a greenhouse gas. Knut Angstrom pointed this out in 1901, and showed experimentally that adding CO2 has very little impact on climate.
Rasool and Schneider confirmed this in 1971.
I generated this graph using the RRTM-LW model, which shows how little impact CO2 and CH4 have on earth’s radiative balance. Even a huge increase in CO2 or CH4 has minimal impact on climate. H2O is far and away the dominant greenhouse gas on earth.