But you mean in a sustainable way of course. Self sufficient colonies.

I suspect we'll need that oil R.L. I notice you haven't quit the astro business and tried to live sustainably on a victory garden and 10 speed bike. I'll bet you do your best though.

We're gonna need it. I'm more concerned about what comes after the heat. There are feedbacks of the greenhouse system both positive and negative and it may get cold soon after peak production of oil and CO2. Kevin Costner returns in "Iceworld". That's more of a disaster for life on Earth, human and otherwise, than "Fernworld". We'll survive. Some will be the cadaver relics of a bygone era. Picture a frozen congregation waiting to be raptured, a cautionary tale for our descendents.

We also may find that there's no going back. What if we get to a point that the atmospheric CO2 is high enough that without human intervention things change in shorter timescales that has been our experience? Ever see a map of contrails from air traffic over the lower 48? TechCiv heats AND cools. We're like Indiana Jones. The trap door has closed solidly behind us and we need to solve the mystery and find the golden statue to leave alive. It's the fossil record or type 1 civ for most of us at this point. Then there's NEOs and GRBs and rogue black holes. Mother ships perhaps... ;-)

David Brin's "Earth" makes a solid arguement for the above. I've adopted much of it's philosophy as a perspective on the future of humans on Earth.