Dr. Stephen Kaffka is professor emeritus of cooperative extension and specialist in the Department of Plant Sciences at the University of California, Davis.  He directs the California Biomass Collaborative (http://biomass.ucdavis.edu/publications/). He has carried out agronomic research on crop production, resource use efficiency and sustainable farming practices.  He has also worked on agriculture and water quality projects including the use of salt affected lands and low-quality water supplies for biomass production using salt-tolerant grasses in the San Joaquin Valley of California, and agricultural and water quality issues in the upper Klamath Basin. He is an advisor to the Institute of Transportation Studies based at U.C. Davis on bioenergy issues.  He has advised the California Energy Commission and its Clean Transportation Program, and has served as an ex officio member of the state’s Bioenergy Interagency Work Group.  He participated on the California Air Resources Board’s Sustainability Standards advisory committees on the state’s low carbon fuel standard. He served as an invited reviewer of USEPA’s third triennial report to congress on Biofuels and the Environment (spring 2023), was a member of a National Research Council’s committee producing the report: the Renewable Fuel Standard, Potential Economic and Environmental Effects of US Fuel Policy. He helped author the SCOPE report:  Bioenergy and Sustainability:  Bridging the Gaps.   From 2003 to 2007 he was director of the Long-Term Research on Agricultural Systems Project at UC Davis, focused on the sustainability of farming systems in California.  He supports the competitive grant program for the state’ Dairy Digester Research and Development program and the Alternative Manure Management Program.  Most recently has worked on alternative crops and sustainable management of dairy-forage systems in California, dairy nutrient recovery and reuse, and IPM practices in sugar beet production.