Reasoning Behind Cooling Predictions
Quite often, the justification for the few global cooling predictions in the 1970s is overlooked. Probably the most famous such prediction was Rasool and Schneider (1971):
"An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5°K."
Yes, their global cooling projection was based on a quadrupling of atmospheric aerosol concentration. This wasn't an entirely unrealistic scenario - after all, sulfur dioxide (SO2) emissions were accelerating quite rapidly up until the early 1970s (Figure 2). These emissions caused various environmental problems, and as a result, a number of countries, including the USA, enacted SO2 limits through Clean Air Acts. As a result, not only did atmospheric aerosol concentrations not quadruple, they declined starting in the late 1970s
Similarly, if we now limit CO2 emissions, we can also eventually get global warming under control.