A limited nuclear war would solve, or at least stall, global warming. Done correctly, at the correct level, it could actually reverse global warming. And, given that those in the know will be well out of harm's way, it would also serve to eradicate the annoying cannibals.

Mate, we gotta start a movie company! (or possibly an off-grid community)

As you say, we're not that far off such a scenario. From where we are now things could happen very quickly. Within a few years even.