From the studies I've seen and discussions I've followed, there's three scenarios that will make the planet uninhabitable:

• the oceans heat up to the point where they stop producing oxygen,
• we run out of drinkable water, or
• we kill off pollinators and run out of food.

Those are all entirely possible and will make the planet uninhabitable for humans.

I mean... obviously it won't make the whole planet inhabitable, but billions will die when 90% of the planet is inhabitable. The last of which might be wiped out when the world fights over access to those remaining 10%.

Well obviously the tropical Antarctic archipelago will be habitable for humans.

Catastrophes don't need to kill everyone to still be considered catastrophic. D'uh. Remarkable insights.