In the ten commandments, God says that thou shall not kill. In doing so, this would theoretically include the environment considering it is made up of many living things, including plants, grasses, animals, insects, etc. Additionally, without a healthy, clean environment, no living things would even be able to sustain life. By not protecting the environment or by harming it altogether, humans would be indirectly killing living things, and, in turn, sinning.
