This weekend, I listened to Speaking of Faith with Krista Tippett. Her guest was Shane Claiborne who writes about and practices "new monasticism." He lives with a group of other Christians, and together they try to live simply and responsibly. This move is not directly related to a desire to be more sustainable, though that motive does come through in the interview. Rather they are motivated by the words of the Bible to care for one another and life as Jesus did. What's especially interesting to me is that Shane was heavily involved in the politicized evangelical movement of the 90s, but turned his back on it when he realized that they weren't actually doing anything to make the world a better place. He didn't directly express his views on abortion or gay marriage, but he did say that the idea that global warming is a hoax meant to distract us from the real issues - abortion and gay marriage - is ridiculous. I thought it was a very nice, thoughtful interview, and one more example of a potential Christian environmentalism.
Here's a link to the show's website with lots of additional information.