Fyi, I’m an Earth Scientist working more than 20 years along with others that contribute heavily to the IPCC climate models, and advise the US executive branch on climate issues. I do know a thing or two. Humans have done pretty well through the last ice age when global temperatures were, on average, about 6°C cooler than now. Proto-humans and other primates have lived in much warmer climates than now. Humans can and likely will survive the climate crisis.
The biggest questions are how warm and how fast? How will we sustain ourselves. Globally, we need to shrink in population, and by all accounts it looks like with populations advancing few children are born and later.
I’m not at all optimistic about climates impact on us, but to say we’ve lost is not helpful.