Even if we manage to terraform and colonize another planet - that's not going to save us, if we destroy that other planet as well.
And whatever other planet we do terraform and colonize is going to be a lot more fragile and a lot easier to destroy than earth is.
If we can't manage to not destroy earth, there's no way we can manage to keep another planet going.
So, we really should do everything to train and master those planet-preserving skills here on earth, because if we ever do settle another planet, we are going to need them!
And whatever other planet we do terraform and colonize is going to be a lot more fragile and a lot easier to destroy than earth is.
If we can't manage to not destroy earth, there's no way we can manage to keep another planet going.
So, we really should do everything to train and master those planet-preserving skills here on earth, because if we ever do settle another planet, we are going to need them!