I'd say anything but climate change, it's an ongoing scam. "we only have 10 years!" has been a meme for these activists since at least the 80's (can't say i followed it much during the 70's, might have been a thing back then too).
Depends what you mean by climate change. If you are talking about the current climate change movement then perhaps i would i agree with you. However I am referring to climate change that could be caused by anything - a large enough solar flare from the sun could wipe every human being off the face of the planet through radiation, a gravitational shift could cause cataclysmic weather patterns, the earth could enter it's next cycle i.e. ice age, hot house etc. Humans are incredibly vulnerable to even the slightest change in temperature i.e. 200 degrees or so.