Riley Dunlap argues that the environment serves three basic functions for humans:
1. The environment provides the resources essential for life-they include air, water, and materials used to create shelter, transportation, and other necessities.
2. the environment serves as a waste repository-more so than other living species, humans produce a huge quality and variety of waste products-bottles, boxes, papers, sewage, and garbage.
3. the environment "houses" our species-it is our home, our living space, the place where we reside, work and play.