For an excellent, entry-level presentation of the theological dimensions of the global warming controversy, you couldn't do better than Dr. E. Calvin Beisner's 7-page address given at the Vatican conference, “Climate Change and Development,” a couple of weeks ago.
Dr. Beisner, an Associate Professor of Historical Theology & Social Ethics at Knox Theological Seminary, entitled his talk, "Climate Change and the Responsibility of Civil Society: Some Biblico-Theological Aspects of the Global Warming Debate." You'll find a PDF version right here.
Again, it's a very good piece. And don't miss the added page at the end with some great reading suggestions for those who want to go further.