Preserving nature is to some a spiritual issue, as illustrated by the below excerpt from an article on preaching the environment:
http://www.eco-justice.org/3layers.asp While this isn't for everyone, it's an interesting take on an ongoing discussion.
"On an even deeper layer, there is important preaching where the direct focus is not on "nature" or "the environment," but which is essential for sustaining the environmental struggle in the church. This preaching addresses the profound pastoral issues that trouble, and can even paralyze, those who are in touch with the earth's distress. The church needs to speak to sin, guilt, repentance, forgiveness and grace as we individually and collectively participate in the destruction of the earth. New words need to be spoken about both anger and hope in the face of the enormous powers that are shaping our world. In the face of the rapid extinction of species, the loss of habitat and wild lands, and profound changes to the global environment, pastoral sermons must speak to grief and loss in ways that bring us to active resistance, not to quiet acceptance."