In 1999, he became the dean of the Yale School of Forestry and Environmental Studies at Yale University, New Haven, Connecticut. He served the school as the Carl W. Knobloch, Jr. Dean and Sara Shallenberger Brown Professor in the Practice of Environmental Policy when he retired from Yale in 2009 to assume a professorship at Vermont Law School in South Royalton, Vermont.[3] Speth was succeeded as Dean at Yale by Sir Peter Crane.[4]