While at AWRA in Albuquerque, I was able to attend a talk by Bill McKibben (founder of 350.org and active participant in OWS) at a neighboring conference (The Quivira Coalition for 21st Century agriculture).
I asked if he had bought the domain "450.org" (we are now at 390 ppm and emitting record volumes of GHGs).
He was simultaneously defiant ("we must work hard") and pessimistic ("we're gonna see temperatures jump by 7 degrees F"). In a well-practiced rant, he attacked overconsumption ("people are living in starter castles for entry-level monarchs") and geoengineering ("geoengineering is junkie-economics. Desperate for a fix, people make up any story -- no matter how implausible -- to keep up their habit."), but he didn't go where his co-speaker (Bill DeBuys, author of A Great Aridness) had already ventured: prepare for a Southwest emptied by high temperatures.
Bottom Line: McKibben says "never give up!" I say be prepared!