My opinion has always been that whatever damage we as a species have done, is already done and in all likelyhood not going to be repairable. Society as a whole just will not come together enough to influence a massive change that woudl be needed. So that said, we should up the space program 10 fold and hope for technology to catch up and allow us to not make the same mistake with another planet. But I do like my sci-fi movies so my brain likes to go that route....
