Comment by shoo
8 years ago
It's maybe worth drawing a distinction between things like "species extinction" versus "civilization collapse" and "massive reduction in carrying capacity".
I think it is much easier to have one or both of the latter outcomes in the med term (the next few hundred years, say) without it necessarily ending in human extinction.
Yeah. There's a whole hierarchy from "inconvenient weather" to "natural disasters" to "cities wiped off the map" to "civilization collapse" to "all civilization collapses" to "we're back in the stone age" to "humanity goes extinct" to "vertebrates go extinct" to "almost everything goes extinct" to "earth can no longer support life as we know it". Each level is a couple orders of magnitude more severe than the last, and each level is a couple orders of magnitude less likely.
The first is already happening. The second is highly likely. #3 and 4 are possible, but beginning to strain the bounds of likelihood. Somehow whenever global warming comes up people tend to jump to the last level, ignoring all the other steps and the massive reduction in complexity that has to happen without adaptation from any other lifeform for us to get there.