Theological basis for Christians to be environmentally conscious?

Since we believe that God made everything (including this world), we are obligated to take care of the creation. It's pretty poor thanks if we destroy our environment, isn't it? God gave us this world so that we could be caretakers of it, not so that we could wreak absolute havoc on it on a whim! I'm not a theologian, but that's just my take on it!