Since his undergraduate major in political science, Dan has maintained an interest in understanding the policy context for his environmental research. Through co-teaching courses with John Holdren for many years, Dan developed an interest in energy technology, wanting not only to understand what is causing climate change but also how to fix it. His initial focus was on carbon capture and storage, a subject he continues to study through a project to understand offshore injection in ocean sediments. Through advisory roles with private companies and the U.S. EPA, he also studied the use of biomass to make low-carbon liquid fuels and its impact on the environment. From 2009 to 2017, Dan served on President Obama’s Council of Advisors on Science and Technology (PCAST), working on reports to the President on a wide variety of subjects in science and technology policy including energy technology and national energy policy, agricultural preparedness, climate change, and STEM education. In 2015, Dan became the director of the Science, Technology and Public Policy (STPP) program at the Belfer Center for Science and International Affairs at the Harvard Kennedy School. In that capacity, he oversees a team of research fellows who work on a wide variety of issues, from energy and environmental policy to cybersecurity and digital technology policy.