People had another cause to worry over back in those days, this being the cold war between the west and the east. With the demise of the Soviet Union came the freedom (for some) and need (for others) to find new causes to fight for, climate change being one of them. The USA was hit by a number of record-setting heat waves in the 30's [1,2] which are probably best-known under the colloquial term "Dust Bowl" -
the 1930s (the Dust Bowl years) are remembered as the driest and warmest decade for the United States, and the summer of 1936 featured the most widespread and destructive heat wave to occur in the Americas in centuries [3]. Even though many of the temperature records set in those years still stand [4] there was no talk about climate change because people were too busy trying to survive the dust bowl and the resulting economic effects while still reeling from the great depression which preceded it.
[1] https://ui.adsabs.harvard.edu/abs/2016EGUGA..1815380C/abstra...
[2] https://en.wikipedia.org/wiki/1936_North_American_heat_wave
[3] http://voices.washingtonpost.com/capitalweathergang/2010/06/...
[4] https://en.wikipedia.org/wiki/U.S._state_and_territory_tempe...