Sander van der Leeuw pioneered the application of the complex adaptive systems (CAS) approach to long-term human–environment dynamics. In the 1990s he led an interdisciplinary research project applying CAS to environmental problems spanning southern Europe—the first of its kind. In the 2000s, he co-directed a similar project on invention and innovation. He taught in Amsterdam, Leyden, Cambridge (UK), and Paris before becoming the founding director of Arizona State University’s interdisciplinary School of Human Evolution and Social Change. He is now a foundation professor in that school and in the School of Sustainability, and a director of ASU’s Complex Adaptive Systems Initiative. He is external professor of the Santa Fe Institute, and a corresponding member of the Royal Dutch Academy of Arts and Sciences. In 2012, he was awarded the title “Champion of the Earth for Science and Innovation” by the United Nations Environment Programme.