claim: The human contribution to global warming was about 0.01°C.
evidence: Keeling’s Tellus article of 1960 presented the first monthly CO 2 records from Mauna Loa and Antarctica (1957 to 1960), finding a “distinct seasonal cycle…and possibly, a worldwide rise in CO2 from year to year.” By the 1970s, it was well established that the increase of atmospheric carbon dioxide was ongoing and due to anthropogenic emissions.