Yep, by life I meant "life on Earth". I guess I should have clarified. What I mean is, if Earth gets destroyed, all life everywhere (as far as we know it) gets

Yep, by life I meant "life on Earth". I guess I should have clarified. What I mean is, if Earth gets destroyed, all life everywhere (as far as we know it) gets destroyed. So we should do our best, whatever it takes, to make sure we spread life to other planets to mitigate that. Sure we may cause environmental damage to get there, but I think that is far outweighed by the benefit of being a multi-planet species.