I found this interesting estimate of the number of future deaths from global warming, something I'd always wondered about.

https://www.frontiersin.org/articles/10.3389/fpsyg.2019.02323/full

They estimate (only) a billion deaths projected if we can stay under 2C of global warming (which is optimistic and would require becoming a more energy efficient society and diverting from our present path but not totally leaving civilization). Based on that scenario, they estimate that 1000 tons of emissions kills about one future person. That means the average Canadian, who burns about 20 tons per year, is killing about 1-2 people during their lives. From a slightly more positive stance, by not driving and living frugally I'm only killing about 1/4 to 1/2 of my future grandchildren, which is still pretty sad, but I'm also saving approximately one of their lives, which is pretty cool!

Of course these estimates are very inaccurate, as they say, but they're better than making random guesses and being off by orders of magnitude (such as thinking your lifestyle is only killing a tiny fraction of a person so is fine, or thinking that humans will all be wiped out by our lifestyles).