Maybe align himself as a front runner to the Green Party? After all, what's an out-of-work has-been Dem to do? Sit around and eat Cheetos all day watching Talk Shows?
Also he's pickin up the Hollywood money (they'll throw $$ at problems instead of actually doing something themselves with a few exceptions) as well as people are listening to him again. And that's one of the things that Politicians really want, to stand on the soap box and yakity-yak...
As far as the Global Warming issue? I think more that with the destruction of the environment we're gonna have all sortsa crazy weather... big storms, hot/cold swings, earthquakes, droughts, floods, locust swarms... whatever.
It's not going to be that it just gets warmer, it will be violent and unpredictable as things change too quickly.
Course I'm no Scientist or anything..