That's absurd. People have been living in harsh conditions (120°F desert weather, <32°F freezing temps for big chunks of the year) for millennia and likely hund

That's absurd. People have been living in harsh conditions (120°F desert weather, <32°F freezing temps for big chunks of the year) for millennia and likely hundreds of thousands of years with none of the technology we currently enjoy. There are more people now than ever before. I can't even see an all out nuclear war combined worth +6°C average temperature increase leading to extinction. Some people somewhere will survive. Maybe many or even most might die in such a scenario but to wipe out humanity, I don't think that possibility currently exists.