Being a good steward of God’s creation is part of the mission we, as a people, were given in Genesis. While I will be one of the first to stand up and declare my skepticism toward the belief that global warming exists and that man is a primary cause of it (I’ve seen much of the data, and - more importantly - the science behind it, and like John at VerumSerum, I find it a race to reach a foregone conclusion for political gain), I also believe that there are a number of basic “sustainable” ways of living which demonstrate our love for God in caring for His creation, and - in this society - would serve to hold Him to to show that He is the One True God.
I don't understand (yet) all of the data that is sending some of my Christian bothers and sisters into action regarding ecology but I know that my other brothers and sisters in Christ that refer to the former group as liberal nut jobs are flat wrong. We are stewards of God's creation. Caring for it glorifies our Creator ... it doesn't make us whacky - we have other ways to demonstrate that.