It's interesting to compare and contrast climate change and nuclear war. When I grew up it was common knowledge that the world could end at any point in time via nuclear holocaust. It was more or less the most direct existential threat to humanity the world had ever seen. It did spawn some nihilistic artistic movements and general detachment, but I'd say that the anxiety people felt was much lower than what you hear from the younger generations re: climate change.

Even on this site, you'll see many people say that they don't want to have kids because of climate change. I don't recall people in the 80s saying they wouldn't reproduce due to the future threat of nuclear war.

I'm not sure what the exact cause is but I suspect it has something to do with the how the different generations process authority and media messaging. Earlier generations being much more skeptical of what they are told.