HELMUT GEIST is professor of human-environment interactions at the University of Aberdeen in Scotland, United Kingdom. From 2000 until 2005 he was executive director of the IGBP-IHDP Land-Use/Cover Change (LUCC) project at LUCC's International Project Office at the University of Louvain in Louvain-la-Neuve, Belgium. His research interests include political ecology, sustainable land use, land-change theory, and human-driven environmental changes such as land degradation, deforestation, desertification, and urbanization. Based at universities the United Kingdom, Belgium, Germany, and the United