We are facing an environmental crisis that some say is ushering a new geological epoch, the Anthropocene, one that threatens not only a great deal of life on the planet but also our understanding of who we are and our relation to the natural world. In the face of this crisis it has become clear that we need a more sustainable culture. In fact the language of sustainability has become pervasive in our culture and has deeply ingrained itself in our understanding of what living a good life would entail. "Sustainability," however, is a contested word, and it carries with it, often implicitly and unacknowledged, deep philosophical claims that are entangled with all kinds of assumptions and power relations, some of them very problematic. This book attempts to set this urgent goal of sustainability free from its more reductive and harmful interpretations and to thereby apply a more thoughtful environmental ethics to current and emerging technologies, particularly those involving reproduction and the harnessing of energy that dominate our elemental relations to sun and air, wind and water, earth and forest.