Environmental ethics—the study of ethical questions raised by human relations with the nonhuman environment—emerged as an important subfield of philosophy during the 1970s. It is now a flourishing area of research. This article provides a review of the secular, Western traditions in the field. It examines both anthropocentric and nonanthropocentric claims about what has value, as well as divergent views about whether environmental ethics should be concerned with bringing about best consequences, respecting principles and rights, or embodying environmental virtues. The article also briefly considers two critical traditions—ecofeminism and environmental pragmatism—and explores some of the difficult environmental ethics questions posed by anthropogenic climate change.