He specializes in environmental ethics and ethical theory, and he teaches, among other courses, PL345, Environmental Ethics, one of the Environmental Affairs core courses. His Ph.D. dissertation (Boston University, 1997) was titled "Thoreau's Vision of a Good Life in Nature: Towards an Environmental Virtue Ethics." Together with the noted biologist Richard Primack he wrote the article on Environmental Ethics for the Encyclopedia of Biodiversity (Harcourt Brace 2000) and he has published in numerous scholarly journals. He has worked as a Park Ranger for the National Park Service in the Pacific Northwest and has lobbied Congress and three state legislatures as a representative of the Sierra Club and the Wilderness Society.