I guess people didn't understand my point. If we don't curb our carbon emissions, we're certainly going to have a climate that we never lived and it will kill a lot of people. But it's not unlimited, at some point we will not be able emit more carbon, because there's no more or we lost the ability to do so. So while fewer than today, there will probably still be habitable places like Nothern Canada and Russia. I think humanity would be able to survive there, although much smaller and the centuries of disasters would have destroyed our civilisations as we know them.

People probably thought I'm denying the urgency to do an ecological transition, but I'm not. I'm trying to comment on what would actually happen, similarly to previous comment saying that the planet itself is not going to die.