I've just read an article as part of assesment regarding Christian's and their responsibility to take care of the earth.
The phrase - "When you love someone, you take care of their posessions" really struck a chord with me. If I love God, I will take care of all that he owns.
Read this webpage and think about it.
(Sorry I can't link it, something is up with my links!!)
God man a job when he was first created: Genesis 1:26. Then God said, "Let us make man in our image, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth and over all the creatures that move along the ground."
This job hasn't expired - we are still called to take care of the earth and all that is on it. We aren't supposed to be taking advantage of the Earth and taking all we can get from it. We are merely tenants (Lev. 25:23-24. The land is mine and you are but aliens and my tenants.)
We don't have to be extremists, but we certainly can show responsibility by doing all we can to care for the earth. Recycle, minimise disposable item use, responsible power usage, reduce your carbon footprint etc.
What can you do?