He was the director of Global Climate Change Policy at the United States Environmental Protection Agency for ten years. He was the Coordinator of Science and Technology at the United Nations Framework Convention on Climate Change for nine years. He was the head of the climate change unit at the Organisation for Economic Co-operation and Development (OECD) for three years. He has also worked on the Montreal Protocol and held positions in industry with Texaco and Alcoa.
He is one of the coordinating lead authors of the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize with former US Vice President Al Gore. He advises national governments and industry as an associate with the International Institute for Sustainable Development in Canada and a senior fellow at the World Resources Institute in Washington, D.C.
He was the Chairman of The International Scientific Steering Committee for Avoiding Dangerous Climate Change Symposium on Stabilisation of Greenhouse Gas Concentrations which took place at the invitation of the British Prime Minister Tony Blair in 2005.
In 1989 he co-authored the first report to Congress, The Potential Effects Of Global Climate Change on the United States, and has written a scientific and policy history on climate change and contributed to many publications including the New York Times in an op-ed titled "How Green is My Taxi".
- Smith, Joel B.; Tirpak, Dennis (December 1989). The Potential Effects Of Global Climate Change On The United States. Report to Congress. United States Environmental Protection Agency. EPA-230-05-89-050.
- Hecht, Alan D.; Tirpak, Dennis (April 1995). "Framework Agreement on Climate Change: A Scientific and Policy History". Climatic Change 29 (4): 371–402. doi:10.1007/BF01092424.
- Tirpak, Dennis (December 2008). "The Scientific Basis for National and International Policies, Instruments and Co-operative Arrangements" (PDF). IPCC.
- Dennis Tirpak Biography
- Black, Richard (3 February 2005). "Scientists' grim climate report". BBC News.