A novel ecosystem is an ecosystem that has no historic analogue and has been brought about inadvertently by human agency. Global warming has led to the dramatic proliferation of the world's novel ecosystems, ushering in a new geologic age: the Anthropocene era. This book examines what novel ecosystems are before briefly analyzing their ethical import. It explores how novel ecosystems force us to think more clearly about ecosystem management, and-more generally-about what is "natural." Allen Thompson provides a much needed philosopher's perspective on the debates about value and ethics that currently engage natural scientists and policymakers, and that often pit those advocating preservation and conservation against those who would accept a "post-wild' earth.