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.

Well obviously the tropical Antarctic archipelago will be habitable 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%.

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