Enrique Leff, Senior Researcher/Professor in political ecology and environmental sociology, National Autonomous University of Mexico (UNAM). Dr Enrique Leff is considered a pioneering environmentalist and one of the main authors of the theory and practice of environmentalism; PhD in Development Economics, Paris-Sorbonne (1975) and former Coordinator of the UNEP’S Environmental Training Network for Latin America and the Caribbean (1986-2008). He lectured at UNAM (Universidad Nacional Autónoma de México) full-time from 1973-1986 before becoming coordinator of the Environmental Training Network for Latin America and the Caribbean (1986-2008) and coordinator of the Mexico City office of the Regional Office of Latin America and the Caribbean of the United Nations Environment Programme (2007-2008), after which he returned as senior researcher/professor in political ecology and environmental sociology, to the Institute of Social Research, National Autonomous University of Mexico (UNAM). Dr Leff has worked since 1975 in the fields of environmental philosophy and epistemology; political ecology, ecological economics and environmental sociology. He is the author of over 150 books and articles published in Mexico, Spain, Argentina, Brazil, Colombia, Chile, USA, England, Italy, Germany, Holland, and other countries in Latin America. Ecología y Capital (Ecology and Capital), Saber Ambiental (Environmental Knowledge) and Racionalidad Ambiental (Environmental Rationality) are among his more influential books. Forthcoming is his most recent book, La Apuesta por la Vida: Imaginarios Sociales e Imaginación Sociológica en los Territorios Ambientales del Sur.