Sufficiently large Large Igneous Province
Sufficiently large asteroid
Burn-it-ALL (12k GtC)
Survive but not very fun:
-RCP 8.5: Scattered, roving bands of hunter-gatherers living at high latitudes a few centuries from now seems like an adequate adaptation to Bad Climate Change
-Geomagnetic storm: Just a hiccup
-Vacuum decay: Universe-as-we-know-it ends, so do humans.