As natural resources are depleted and global population grows, environmental security is becoming an increasingly salient dimension of long-term peace. In this article, we discuss current views of environmental security and go on to argue that the social psychological dimensions of resource-based conflict should also be addressed. We briefly describe six examples of such conflicts, and conclude that psychologists can play an important role in promoting peace, by bringing attention to, and helping find ways to mitigate, the psycho-ecological dimensions of armed conflict.