[safety1st]

Fair point on #1 but I imagine the probability of a meteor strike that literally boils the planet is a lot lower than a strike in general.

Regarding #2, the solution for self-sufficient agriculture in Antarctica and on the Moon/Mars is the same: hydroponics.

Only it's much easier to do hydroponics in Antarctica. You can melt that ice for fresh water. You can harvest all kinds of nutrients from the ocean. The Antarctic seas have huge oil deposits to provide limitless energy. An Antarctic colony pretty much just needs lots of weather-hardened infrastructure, it's tough, but well within reach of current tech.

Self-sufficient Moon/Mars hydroponics is way harder. Water is far more scarce. Where do you obtain the nutrients for plant life in situ? Not sure it will all require exotic systems that haven't been invented.

My premise is basically that the political will for a self sufficient colony that "backs up" human society doesn't exist. If it did we would just have some countries agree to amend the Antarctic treaty and do it. It could probably even pay for itself by exporting oil. But no one genuinely cares so we just write scifi stories on the Internet instead.