Noun
global cooling (uncountable)
Global climate change in the form of declining average temperatures; which was conjectured in the 1970s.
You know, back in the '70s - I remember the '70s, we were told there was global cooling. And everyone was told global cooling was a really big problem. And then that faded. Ted Cruz
Global cooling continued until there was a major reversal from cooling to warming indicated in the Southern Ocean at around 42-41 million years ago. Source: Internet