Thomas Princen explores issues of social and ecological sustainability at the School of Natural Resources and Environment at the University of Michigan. He works on principles for sustainability (e.g., sufficiency), overconsumption, the language and ethics of resource use, localization, and the transition out of fossil fuels. Princen is the author of Treading Softly: Paths to Ecological Order (2010/2013) and The Logic of Sufficiency (2005), and lead editor of Confronting Consumption (2002), all published by MIT Press. The last two were awarded the International Studies Association's Harold and Margaret Sprout Award for the "best book in the study of international environmental problems." He is co-editor of The Localization Reader: Adapting to the Coming Downshift (MIT Press, 2012), co-author of Environmental NGOs in World Politics: Linking the Local and the Global (Routledge, 1994) and author of Intermediaries in International Conflict (Princeton University Press, 1992/1995). Princen is currently working on three book-length projects: Ending the Fossil Fuel Era: Keep Them in the Ground (contract, MIT Press), Distant Horizons: An Ethic of the Long Term, and The Politics of Urgent Transition.