We may wish we're doomed to space colonization.j

"The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand." - Carl Sagan, https://en.wikipedia.org/wiki/Pale_Blue_Dot

What he's saying is that anything viable is too far away. Forget about the Moon or Mars, we cannot protect a population against radiation, and if we could we may as well build that same habitat here on our then presumably inhabitable planet that we're already on.

Don't just use the planet up and walk away from it, because there's nowhere to go.