The argument isn’t that the whole earth becomes inhospitable. But that certain regions do, and the rest will have their climate differ drastically.
If you live on the coast and the water level rises, your home is inhospitable, even if someone 100mi inland is fine.
If you live in a region that usually was 90F in the summer and is now >110F regularly, that’s going to cause problem.
There isn't enough fossil fuels in the ground for us to burn to cause a 20F+ increase in annual summer temperatures globally...
Their argument is not predicated on a 20F+ temp rise globally; their argument is about regions.
Most of the increase in local temperatures are overnight lows in the Winter. I'm not sure there's any peer-reviewed mechanism to suggest that daytime Summer highs will increase 20F+ due to greenhouse gases in any parts of the world.
So your argument that this statement by them: "If you live in a region that usually was 90F in the summer and is now >110F regularly, that’s going to cause problem." is hyperbole, then? Okay, going with that, what temperature range would you find credible, as to describe a region that is seeing wilder swings in summer highs?
https://ourworldindata.org/grapher/summer-temperature-anomal...
Somewhere on the order of 1-2C if you start from the 1850s.
I'm not talking about global, look at individual countries:
- Andora (5C/9F)
- Montenegro (5C/9F)
- Japan (4C/7F)
- Italy (4C/7F)
- Spain (3C/5.4F)
Even with current rates I think we'll easily hit a 20F increase in several regions.
Your own source affirms the other person's point, not yours; switch to the table view and sort by absolute change.