I just listened to an interview with Tom Friedman, author of Hot, Flat, and Crowded.
He makes the case that we need systemic change in the way we live to face the coming challenges. The primary challenges are global warming (hot), a globally growing consumer class (flat--yeah, I don't get it either), and overpopulation (crowded). It doesn't sound revolutionary in its content, but he makes very strong arguments in the interview and seems to avoid the moral imperative that seems to get many green proponents pegged as emotional extremists. Although, he does get pretty emotional about it all. Who can blame him?
I also recommend the TED presentation by Mark Bittman on the problems with the western diet. He explicitly avoids the emotional reasons to reduce meat consumption, and makes a strong argument for going (mostly) vegetarian.