It's also true that there's no DEFINITIVE ABSOLUTE PROOF that pressing the nuclear launch button will clause a MAD-style nuclear escalation.

But still, there's good reason to believe it would, so it'd be irresponsible to push the button given other reasonable alternatives.

"You can't ever know FOR SURE that this destroy life as we know it!" has to be the least logical form and most confusing of climate change skepticism out there. The fact that anyone would consider this argument, on its own, even remotely compelling, is... oy.