If the justification for becoming a multiplanetary civilization is that it will mitigate the threat of extremely infrequent catastrophes (as in, they happen onc

If the justification for becoming a multiplanetary civilization is that it will mitigate the threat of extremely infrequent catastrophes (as in, they happen once over the course of thousands or even millions of years), doesn't that suggest we can afford to wait a bit? I think colonizing Antarctica and colonizing Mars are two totally different solutions, colonizing Mars solves problems that happen on geological timescales, I can't think of any problem offhand that colonizing Antarctica solves.