Global Warming and our Changing World

It would seem pretty lame if humanity refused to clean up its technological act, and became similar to the locust-like creatures in "Independence Day." If we were to ditch our problem planet and just pick up and go to Mars, what would happen? First we'd terraform, and then after a couple of hundred years of industrialization, we might decide to bail again.

I've heard that it's possible that in order for the human race to survive planetary disaster, we must have outposts on other planetary bodies. I'd like to see us develop clean fuels simultaneously.