We do have enough nuclear weapons to kill all humans
It's not clear this is the case, actually, despite it being a part of the common culture. Nuclear winter style scenarios are possible, but even then it's not clear that all humans would die.
OK. I was really just trying to say that I agreed that there was some chance of a rapid violent end of humanity.
Nuclear winter -> reglaciation -> meteorite strike - or whatever scenario you prefer.
Stanislav Petrov is a rather famous person (of course only on Lesswrong, not in the real world).
But there is another Russian who saved the world: Vasili Alexandrovich Arkhipov.
On this day in 1962, at the height of the Cuban Missile Crisis Vasili Arkhipov prevented the launch of a nuclear torpedo and thus a possible nuclear war.
It's strange that Petrov attracts much more attention than Arkhipov. E.g. googling "Stanislav Petrov" produces 101.000 results, "Vasili Arkhipov" only 9.040 results. By contrast searching for "Britney Spears" generates about 295.000.000 results. Sorta depressing.
Anyway, let this day be the Vasili Arkhipov Day.