Doubtful that’s how climate change is going to play out. The majority of the planet will still be very habitable the majority of the time. The extremes will be more extreme and there’ll be more “once in a century” types of weather events (think hurricanes and tornadoes where traditionally there weren’t any).

Eventually the inhabitability and the natural disasters will add up to a sizable amount of deaths. But by that point I think we’ll be too far gone. The planet will take millions of years to recover.