Yeah, we're pretty fucked. But before nuclear annihilation or some kind of dramatic climate collapse, I actually think we'll have something else: a massive economic crash.
Worse than the Great Depression. The suffering is going to be catastrophic, with global markets in complete disarray, and famine and war spreading like wildfire (which'll also be catastrophic).
We keep propping up our groaning system with as many fiscal sticks as our government can throw at it, but the whole thing is buckling. Governments are in debt up to their eyeballs, as are individuals, and global supply lines are already breaking down. Not sure if it'll start this year, ten years from now, or 25, but once the dominoes start to fall, it isn't going to be possible to stop them. Not until they've run their course.