Much as I like Randall Munroe and xkcd, I don't see any sources cited in that comic.
I don't know that we know, precisely, how fucked we are yet, but I do think it's clear that humans are having an effect, and we know very convincing reasons for why we're having an effect, so we should work to reduce that effect regardless of whether we're fucked in 100 years if we continue this way, or if it will take 1000.
I don't know that we know, precisely, how fucked we are yet, but I do think it's clear that humans are having an effect, and we know very convincing reasons for why we're having an effect, so we should work to reduce that effect regardless of whether we're fucked in 100 years if we continue this way, or if it will take 1000.