[CalRobert]

For what it's worth I think we're largely having an agreement. Ensuring our planet remains reasonably habitable should be the highest priority. That part of me which desires to see humanity survive even if we fail in this endeavor would like to see a backup planet (presumably Mars) at the species' disposal.

[crpatino]

Given that Mars would be orders of magnitude harder to terraform than, well... Terra. Why do we even have to consider it?

There's no plan B. Each of us is part of The Red Thin Line (href = http://en.wikipedia.org/wiki/The_Thin_Red_Line_%28Battle_of_... ), whether we like it or not. The only question worth asking is: Am I going to hold my ground or not?