Dr David Allen is a Regents Professor in Chemical Engineering at the University of Texas at Austin. He is Director of the Center for Energy and Environmental Resources, a group of approximately 100 graduate student, faculty and staff researchers working in areas of chemical process science and technology, and atmospheric emissions. He has led large air quality field studies aimed at quantifying, through direct measurements, greenhouse gas emissions for oil and natural gas supply chains. He has also developed models of material and energy flows within the US chemical industry and used those models to characterize the transformation of chemical manufacturing in the United States from petroleum to natural gas liquid feedstocks. His current work is applying these material and energy balance models to assess systems scale impacts of increased circularity in plastics manufacturing. He has served as an advisor for U.S. federal, state and local governments and from 2012 to 2015 chaired the U.S. Environmental Protection Agency’s Science Advisory Board.