"But there is equally--indeed primarily--a dimension here of the doctrine of world conservation. When man gets out of step with God, 'nature' gets out of step with man and is corrupted and polluted from its purity. Thus, in Gen. 3, the breach between God and man had its immediate corollary in the thorns, thistles and sweat which thenceforward marked man's relationship with his physical environment (Gn. 3:17ff.). The Old Testament follows this teaching through consistently. The very land itself becomes polluted by the sins of its inhabitants (Jer. 3:1-3), and its beauties are destroyed by human pride (Is. 2:12-17). We see this in action wherever once-beautiful valleys are disfigured by the slag-heaps and debris of industrial covetousness or wherever rivers become the running sores of careless pollution."
This too is from Motyer's commentary on Amos, but I wanted to give it its own posting. I think it's a powerful description on why Christians should be active conservationists!
For more on Christian conservation see works by Loren Wilkenson, a Regent College faculty member. He has written many scholarly and popular articles developing a Christian environmental ethic and exploring the human relationship to the natural world in its environmental, aesthetic, scientific and religious dimensions.