What makes you say that? To me it seems like the worst case is probably human deaths in the hundreds of millions, not extinction.
I think this underestimates the societal repercussions of an initial set of hundreds of millions of deaths.
Millions of deaths probably means billions of refugees looking for new places to live, probably in places that are already struggling with the changes themselves.
Global instability is likely to lead to more conflict and war without any guarantees of end. A vast population reduction of vulnerable people for a lot of people IS extinction.
I’m sure where you got that impression. But language matters and the worst case outcome isn’t a situation that “kills humanity”. I was asking for clarification in case there was something I was missing in terms of impact that would actually lead to extinction, which by definition means a complete end to all human life.
i appreciate your language as well.