Holdren taught at Harvard for 13 years and at the University of California, Berkeley for more than two decades.
His work has focused on the causes and consequences of global environmental change, population control, energy technologies and policies, ways to reduce the dangers from nuclear weapons and materials, and science and technology policy.
He has also taken measures to contextualize the United States' current energy challenge, noting the role that nuclear energy could play.

Holdren was involved in the famous Simon–Ehrlich wager in 1980.
He, along with two other scientists helped Paul R. Ehrlich establish the bet with Julian Simon, in which they bet that the price of five key metals would be higher in 1990.
The bet was centered around a disagreement concerning the future scarcity of resources in an increasingly polluted and heavily populated world.
Ehrlich and Holdren lost the bet, when the price of metals had decreased by 1990.

In 1981, Holdren was awarded a MacArthur Fellowship (informally known as the "genius award") for his efforts to promote world peace through energy management.

Holdren was chair of the Executive Committee of the Pugwash Conferences on Science and World Affairs from 1987 until 1997 and delivered the Nobel Peace Prize acceptance lecture on behalf of Pugwash Conferences in December 1995.
From 1993 until 2003, he was chair of the Committee on International Security and Arms Control of the National Academy of Sciences, and Co-Chairman of the bipartisan National Committee on Energy Policy from 2002 until 2007.
Holdren was elected President of the American Association for the Advancement of Science (AAAS) (2006–2007), and served as board Chairman (2007–2008).
He was the founding chair of the advisory board for Innovations, a quarterly journal about entrepreneurial solutions to global challenges published by MIT Press, and has written and lectured extensively on the topic of global warming.

Holdren served as one of President Bill Clinton's science advisors (PCAST) from 1994 to 2001.
Eight years later, President Barack Obama nominated Holdren for the position of science advisor and Director of the Office of Science and Technology Policy in December 2008, and he was confirmed on March 19, 2009, by a unanimous vote in the Senate.
He testified to the nomination committee that he does not believe that government should have a role in determining optimal population size and that he never endorsed forced sterilization.
Holdren taught at Harvard for 13 years and at the University of California, Berkeley for more than two decades. His work has focused on the causes and consequences of global environmental change, population control, energy technologies and policies, ways to reduce the dangers from nuclear weapons and materials, and science and technology policy. He has also taken measures to contextualize the United States' current energy challenge, noting the role that nuclear energy could play.
Holdren was involved in the famous Simon–Ehrlich wager in 1980. He, along with two other scientists helped Paul R. Ehrlich establish the bet with Julian Simon, in which they bet that the price of five key metals would be higher in 1990. The bet was centered around a disagreement concerning the future scarcity of resources in an increasingly polluted and heavily populated world. Ehrlich and Holdren lost the bet, when the price of metals had decreased by 1990.
In 1981, Holdren was awarded a MacArthur Fellowship (informally known as the "genius award") for his efforts to promote world peace through energy management.
Holdren was chair of the Executive Committee of the Pugwash Conferences on Science and World Affairs from 1987 until 1997 and delivered the Nobel Peace Prize acceptance lecture on behalf of Pugwash Conferences in December 1995. From 1993 until 2003, he was chair of the Committee on International Security and Arms Control of the National Academy of Sciences, and Co-Chairman of the bipartisan National Committee on Energy Policy from 2002 until 2007. Holdren was elected President of the American Association for the Advancement of Science (AAAS) (2006–2007), and served as board Chairman (2007–2008). He was the founding chair of the advisory board for Innovations, a quarterly journal about entrepreneurial solutions to global challenges published by MIT Press, and has written and lectured extensively on the topic of global warming.
Holdren served as one of President Bill Clinton's science advisors (PCAST) from 1994 to 2001. Eight years later, President Barack Obama nominated Holdren for the position of science advisor and Director of the Office of Science and Technology Policy in December 2008, and he was confirmed on March 19, 2009, by a unanimous vote in the Senate. He testified to the nomination committee that he does not believe that government should have a role in determining optimal population size and that he never endorsed forced sterilization.
John Holdren