- Technische Universität Berlin: B.S. (Vordiplom) in Environmental Engineering, 1991.
- Massachusetts Institute of Technology: M.S. in Civil and Environmental Engineering, 1994.
- Technische Universität Berlin: Engineer's Degree in Environmental Engineering, 1995.
- Princeton University: M.A. in Civil Engineering and Operations Research, 1998.
- Princeton University: Ph.D. in Civil and Environmental Engineering, 2000.
Professor Keller’s research addresses two interrelated questions. First, how can we mechanistically understand past and potentially predict future changes in the climate system? Second, how can we use this information to design sustainable, scientifically sound, technologically feasible, economically efficient, and ethically defensible climate risk management strategies? He analyzes these questions by mission-oriented basic research covering a wide range of disciplines such as Earth system science, economics, engineering, philosophy, decision science, and statistics.