John P. Holdren, an American physicist noted for his influence in international efforts to reduce the dangers of nuclear conflict, achieve cooperation in energy-technology innovation, and shape new understandings and policies relating to a workable strategy to ensure sustainable development of the Earth’s resources. Holdren is Chair of the Committee on International Security and Arms Control of the National Academy of Sciences and was a member of President Clinton's President's Committee of Advisors on Science and Technology (PCAST). While a member of PCAST, Holdren chaired studies for the White House on protection of nuclear weapons materials, the U.S. fusion-energy R&D program, and energy R&D strategies to combat climate change. Holdren is credited with playing a significant role in mobilizing the international community of policymakers and scientists to take action in arms control, where he has been a powerfully effective advocate of U.S. attention to the security of nuclear weapons and nuclear materials in Russia.
In December 2008, Holdren was nominated by President-elect Barack Obama to be head of the White House Office of Science and Technology Policy and Science Advisor to the President.