I understand, I just objected to it because I see in my environment that there are seriously people thinking now that climate change can be a human extinction event (though it will be for many other species of course)

There seems to be a 'project fear' movement that thinks it's ok to overblow scientific conclusions in order to sway people to act. I personally think this is a very bad idea as deliberate lies will only lead to deep disillusionment with government and the scientific community. It can also lead to fatalism where people won't act because they believe the worst outcome is already locked in.

And really, the truth about climate change is scary enough as it is. But we do still have the opportunity to mitigate some of the worst of it.

I honestly don't believe "climate change" in and of itself will kill us all off (although there's always that possibility, depending on tipping points and other factors). I'm more worried about how the humans in control of some of the deadliest killing technologies ever devised are gonna exacerbate an already horrifying future as things progress and ever more tension is created by the situations climate change will bring about. Humans (as always) are the scariest part of the equation.

I hold the same worries about A.I. The tech itself (currently just a tool, and honestly not nearly as "advanced" one as many seem to believe) isn't nearly as scary as how the dumbest of our number (our so-called "leaders") are gonna use and / or abuse it.

I honestly believe that if there is a true extinction of humanity (or life in general) on this planet, it's far more likely that a small group of exceptionally stupid humans will inflict it upon us than almost any other "doomsday scenario" I can imagine.