One of the key themes in debates about global security is whether the nature of violence and conflict is changing. A range of problems (or ‘risk environments’) are now being defined as possible sources of violence and instability, intra-and inter-state conflict, transgression of state borders and threats to international peace and security. There is a widely held perception that states and peoples are increasingly vulnerable to a range of transboundary threats that have been exacerbated by the economic, spatial and cultural consequences of globalization. The focus of this chapter is on one such problem – environmental change – and the ways in which it is connected with political violence. This relationship is only one part of a much broader literature on how environmental degradation challenges and potentially reconfigures the ways in which we understand, or should understand, security.