Our politics is intimately linked to the environmental conditions - and crises - of our time. The challenges of sustainability and the discovery of ecological limits to growth are transforming how we understand the core concepts at the heart of political theory. In this essential new textbook, leading political theorist Steve Vanderheiden examines how the concept of sustainability challenges - and is challenged - by eight key social and political ideas, ranging from freedom and equality to democracy and sovereignty. He shows that environmental change will disrupt some of our most cherished ideals, requiring new indicators of progress, new forms of community, and new conceptions of agency and responsibility. He draws on canonical texts, contemporary approaches to environmental political theory, and vivid examples to illustrate how changes in our conceptualization of our social aspirations can inhibit or enable a transition to a just and sustainable society. Vanderheiden masterfully balances crystal clear explanation of the essentials with cutting-edge analysis to produce a book that will be core reading for students of environmental and green political theory everywhere.