Look six posts up. SpaceX has the best blooper reels.
time to TWAT down some aliens and upgrade that spaceship into UFO... so eco, much green
The only planet that does not need colon-ization is Uranus
There's a +!!POSSIBILITY!!+ first 100 yrs Mars will be robot-only colony, until infrastructure is built, none of US will be left behind as none will live to see a completion.
Environmental cost is spiting nothing compared to annihilation meteorite hitting any of the two planets and turning them into a hot mess. One option more, is better than none.
Yeah, it is laughable to tall about the environmental cost. Eventually we do need to leave the planet behind. No sense in colonizing worlds. Better to make structures in space.
We would need some big ass technological upgrade or genetic alteration to be able to exist both in space and on planets, just out of pure practicality.
I could imagine that any permanent colonies would evolve to be different surprisingly quickly. Several generations would likely be enough to notice visible traits.
That said if we made large hollow habitats orbiting the Sun we could create Earth like conditions and have no problem.
Meanwhile the reality: we couldn't create closed ecosystems on a habitable planet, but don't let that get in the way of some tech hopium. :)
