World Socialist Web Site: First change in the global climate was in 1977

The growing impact and dangers of global warming - World Socialist Web Site

The first change in the global climate, and what first alerted climatologists to the possibility of global warming was in 1977. Records from 1950 onwards showed no change in land surface temperatures, despite the CO2 levels rising from 310 to 332 ppm. However, in 1977, the mean surface temperature began to rise at its current rate of 2º C per century.