Dr. Charles Hall is a professor of environmental studies at State University of New York School of Environmental Science and Forestry (SUNY-ESF) in Syracuse. Dr. Hall is a leading authority on biophysical economics and the concept of energy return on investment–applying his extensive research on energy in biological systems to economics and society. He has held research positions at the Brookhaven Laboratory, Marine Biological Laboratory at Woods Hole, Cornell University, University of Montana and, for the last 20 years, SUNY ESF. He earned his doctorate in systems ecology at the University of North Carolina. .