Feminist legal theorist Martha Fineman has suggested that recognition of universal human “vulnerability” should be the starting point for thinking about the state’s obligations to its citizens. This Article argues that Fineman’s concept of vulnerability is valuable for situating political and legal theory within a concern for the natural world. We live in what some scientists have dubbed the Anthropocene—an age in which our collective behavior has serious implications for the flourishing of all life on earth. The concept of “ecological vulnerability” recognizes that humans are vulnerable not only because they age, become ill, and die, but because their survival depends on complex macro- and micro-ecologies—all of which are, in turn, vulnerable to harm. Ecological vulnerability can serve as an important conceptual bridge between critical legal theory and the emerging “green” legal theory, helping to close the gap between projects of social justice on one hand and environmental sustainability on the other. Misused, however, vulnerability analysis can make power relations, and therefore injustice, invisible. Legal and political theorists in search of conceptual frameworks appropriate to the Anthropocene must therefore be careful to incorporate a robust anti-subordination principle into their analyses as they adopt the language of ecological vulnerability.