Joshua W. Busby is an assistant professor at the LBJ School of Public Affairs at the University of Texas, Austin. He has written extensively on the links between climate change and security, including pieces for the Council on Foreign Relations and the UN's High Level Panel on Threats, Challenges and Change. Earlier versions of this article were presented at the 2006 American Political Science Association conference in Philadelphia, Pennsylvania; the 2005 International Studies Association conference in Honolulu, Hawaii; and the 2005 conference on Human Security and Climate Change in Oslo, Norway.

For their helpful comments, the author would like to thank colleagues at the LBJ School of Public Affairs, University of Texas, Austin and the Belfer Center for Science and International Affairs at Harvard University, as well as the advisory group for the author's special report on the topic for the Council on Foreign Relations. For their counsel and comments on versions of this article, the author would also like to thank the following: Elizabeth Chalecki, Colin Kahl, Jennifer Mitzen, Patrick Meier, Idean Salehyan, Troy White, Michael J. Williams, Tom Wright, and the anonymous reviewers for Security Studies.