Peter J. Marcotullio is a professor of geography in the Department of Geography and Environmental Science and Director of the Institute for Sustainable Cities, at Hunter College, City University of New York. He also teaches at Columbia University in the Graduate School of Architecture, Planning and Preservation and the School for Professional Studies. Previously, he taught at the University of Tokyo and directed the Urban Programme at the United Nations University, Institute of Advanced Studies, Tokyo. His research interests focus on cities and environmental change at multiple scales.