Mars?

[Jackalope]

If we don't blow ourselves up first, that is.

In any case, it would be a reasonable first step to settle in our solar system. If for nothing else than for ressources.

I am guessing the reason for settling in a different world would be BECAUSE we would have eradicated most of our species by that point and also destroyed most of our solar system.

I dunno - it would seem to me if we had eradicated most of our species (I assume you mean most of H. sapiens), it would take a lot of pressure off the resources we need to live, *and* that we'd have more pressing concerns than getting off of this rock.

I would think that overpopulation would be a huge motivator to find more space. (Though we still have a large number of problems to solve, not the least of which is actually getting there. Then there's the fact that we don't have anywhere to go *to* yet.)