Then you should read the book Six Degrees by Mark Lynas, who read 3000 peer-reviewed papers on the effects of climate change and summarized them, one chapter per degree.

Billions of deaths at three degrees is probably overstating things, but three degrees does bring massive food shortages and hundreds of millions of refugees. At four degrees, billions of deaths doesn't look that unlikely, and it starts getting hard to imagine how modern civilization could survive. More than that is unthinkable.

The book is a decade old but more recent work hasn't improved the outlook at all.