LAURENCE C. SMITH (https://www.edge.org/memberbio/laurence_c_smith) is the John Atwater and Diana Nelson University Professor of Environmental Studies and Professor of Earth, Environmental and Planetary Sciences at Brown University. He is the author, most recently, of Rivers of Power. The Conversation: https://www.edge.org/conversation/laurencecsmith-how-humans-make-the-earth-their-home