Karsten Pruess is a Senior Scientist in the Earth Sciences Division of the Lawrence Berkeley National Laboratory in Berkeley, California, which he joined in 1977. A native of Germany, he holds a Dr. phil nat. in physics from the University of Frankfurt, Germany (1972). He has conducted research in multiphase, non-isothermal, and chemically reactive flows in porous media, including mathematical modeling, analysis of field data, and laboratory experiments. His interests include geothermal energy recovery, nuclear waste isolation, oil and gas recovery and storage, environmental remediation, and geologic storage of carbon. He has published over 130 publications in peer-reviewed journals and is the chief developer of the TOUGH family of general purpose simulation codes, that are in use in approximately 300 organizations in over 30 countries. At UC Berkeley he has taught graduate courses in numerical simulation. Pruess is a member of the Society of Petroleum Engineers (SPE), the Geothermal Resources Council (GRC), and a Fellow of the American Geophysical Union (AGU) and the Geological Society of America (GSA).