There are a large volume of people who believe that demons and ghosts are real: https://www.usatoday.com/story/news/nation/2021/10/28/do-gho...

I say that just to point out that popularity doesn't provide legitimacy. But with that case I'd assume that there just might be a significant overlap between that example and climate deniers.

The doom scenarios have enough possibility and probability to warrant being taken seriously. Wishing it away on future generations is psychopathic.