Since the end of the Cold War, environmental matters -- especially the international implications of environmental degradation -- have figured prominently in debates about rethinking security. But do the assumptions underlying such discussions hold up under close scrutiny? In this first treatment of environmental security from a truly critical perspective, Simon Dalby shows how attempts to explain contemporary insecurity falter over unexamined notions of both environment and security. Adding environmental history, aboriginal perspectives, and geopolitics to the analysis explicitly suggests that the growing disruptions caused by a carbon-fueled and expanding modernity are at the root of contemporary difficulties. Environmental Security argues that rethinking security means revisiting the question of how we conceive identities as endangered and how we perceive threats to these identities. The book clearly demonstrates that the conceptual basis for critical security studies requires an extended engagement with political theory and with the assumptions of the modern subject as progressive political agent. Viewed thus on a global scale, the environmental security discourse raises profoundly troubling political questions as to who we are and what kind of world we are collectively making in our efforts to be secure.