Yeah, you can only sort-of make that argument about the last couple of centuries, and you have to say that all the genocides were worth it for vaccines and a steady food supply to do so.

I'm not convinced civilisation could collapse entirely do to climate change, though. Break into small warring pieces maybe, but as long as there's still arable land somewhere people aren't just giving up. And even in the crazy 10C scenarios Antarctica stays on the cool side of temperate.