...I vote we decide on a climate landmark to establish the initiation of the global end of the world party. Anything that's currently illegal due to longer term consequences goes into 'fuck it!' territory. Drugs of all kinds completely legalized; conditions that contraindicate using those drugs like pregnancy are ignored. Social standards around things like sex are dissolved (other than consent - that stays). Just nonstop hedonism, feasting, drinking, fucking, etc while supplies last.

Then when supplies run out, we all hit the big red button at the same time. Nukes. All of them. Detonated in as close a synchronization as we can get them, and our failure of species goes out in as painless as possible of an instant flash.

.....I mean, it's that or slow-burn to death anyway, we got nothing to lose.