This book introduces the concept of the Anthropocene and examines its importance for environmental legal thinking, research and practice. Two main arguments are explored. The first is that much of the scholarship in environmental law that addresses the Anthropocene does not respond to Earth systems science or the difference in scale as we move from local to global systems. Key examples include a focus on anthropocentrism, attempts to constitutionalise environmental protections, the prevalence of legal rights and the idea of ecological integrity. The second argument is that these points of focus derive from the prevalence of idealism in environmental legal scholarship. Idealism in this context does not refer to naivety or the presentation of unrealistic goals. Rather, this book is concerned with idealism as a philosophical commitment to the power of ideas to determine reality and drive future change. As expressed in legal scholarship, this book also argues that idealism involves an abstraction from material reality and a refusal to directly engage those forces that have given rise to the Anthropocene. In response, this book uses a method of critique to uncover the presumptions and presuppositions that underlie environmental scholarship. As a counter to idealism, it also sketches out a framework for materialism in the Anthropocene. This book’s engagement with these questions will appeal to undergraduate and postgraduate students in law, politics, philosophy or the ecological humanities. It will also be of interest to academics in these disciplines and libraries around the world.