Earlier quoted context omitted.
You’ve got it exactly backwards IMO. Terraforming Mars or Venus will take millennia at least, millennia that we don’t currently have the luxury of waiting around for. We need to terraform Earth first — restore some of the damage we’ve done over just the last century or two — before we can think about the much more difficult project of terraforming other planets.
I understand we are at risk of large populations being displaced. But you seem to be under the impression we are facing a human extinction event, is that something backed up by science?
I think that’s a risk on the right tail, although not a very likely one. But even the modal outcomes — 2 or 3 K of warming relative to the preindustrial baseline — will likely kill hundreds of millions of humans and lead to the extinction of countless nonhuman plant and animal species. I’m comfortable saying that we should do whatever possible to mitigate that outcome instead of focusing on creating Martian bunkers for the 1% of the 1%.