Peter Harris has done great things in the environmental movement through Christian conservation organisation A Rocha. If you can spare just 10 minutes to watch something, I think the closing section of a talk he gave in New York recently makes a very strong case for Christian environmentalism. Start at 30:30, and continue until the end of the proper talk at 41:00—or watch the whole thing if you prefer!
Gospel & Culture Lecture Series: Peter Harris from Redeemer Video on Vimeo.