Or rather, it might change how we exist, but it doesn't threaten extinction. Heck, getting more wealthy threatens our current way of life – it certainly changed our old way of life. Things will change – the question is, will humans still be around to see it?

I think so. We've already set up detection for asteroids large enough to end humanity. Now it's just city-destroyers – so, ya know, big relief. But global warming will just raise the cost of agriculture (we have ~50x cost headroom on this), probably create a migrant crisis, perhaps permanently eliminate commercially viable non-factory fish for food, and maybe some other effects. Last I heard, megacat insurance rates were going down, so having more extreme weather events hasn't materialized in any way I'm aware of.*

Honestly, I've mentioned before, I'm underwhelmed by the threats global warming experts predict. It sounds like a walk in the park! It will probably cost less than local zoning policies. Definitely less than our current immigration policy. It even costs substantially less than occupational licensure, if you want to extrapolate from the studies about funeral services. And we're incurring all those costs now, for essentially no reason. I like electricity. That's a pretty good thing I'm getting in return for these costs.

At the end of the day, the current hysterical reaction to the idea we're semi-permanently damaging the planet's ability to support life bothers me. We've changed the world so much, the costs to a collapse of civilization are so high. Why on Earth would you be worried about some extra costs to not having civilization? If civilization collapses, we're all screwed. If it doesn't, I'm optimistic we can get almost all remaining humans up to Netherlands-in-the-1600's level infrastructure. Humans are pretty great, and we care about each other. We can do this, together – because the other option is already so crippling we would surely all be doomed, global warming or no.

* To explain: meta-catastrophe insurance is the insurance that insurance companies buy, typically by cash powerhouses like Berkshire Hathaway. They have correlated risks related to their exposure to e.g. hurricanes. If the entire Eastern seaboard gets hit at once, it massively strains their cash pool. And why not just pay all claims out of that year's premiums? They (ideally) have no cash pool at all, and just get insurance themselves for those extreme, highly correlated events. But that insurance has become cheaper – likely due to the fact that our statistical methods are getting fancier. But no computer can stop a hurricane from destroying a bunch of stuff at once, so there's a limit to the amount of extreme weather event escalation we've already seen.