Can you cite about that worst case scenario? All that I've heard of global warming consequences is a metre or two rise in sea level, flooding of the related areas + changes in agriculture (currently fertile areas suffer, but northern countries may even increase fertility) i.e., a major pain, but nothing near extinction or civilization ending. It would happen slowly enough (over a century) and require some migration further inland (or infrastructure megaprojects - we can have cities below sea-level, see Netherlands for example), but in the long term we would have the same quality of life, just for a smaller global population due to agricultural changes.

Antibiotic resistance, on the other hand, kills our wellbeing and lifespan by making common medical procedures/surgeries impossible, and does so permanently.