Lawrence Livermore National Laboratory

Philip Duffy

Senior Scientist
Atmospheric, Earth and Energy Division

 +1 925-422 3722

Ph.D. Applied Physics
Stanford University
A.B. Astronomy and Astrophysics
Harvard University

Personal Background

Philip Duffy began working at LLNL in 1986, initially in the weapons program and since 1990 in climate research. At LLNL he has had many roles, including physicist, Group Leader, and Deputy Division Leader. From 2011 to 2102, he was a Senior Policy Analyst at the White House Office of Science and Technology Policy, where he handled a range of issues related to climate change. Between 2008 and 2011 he was Senior Scientist, Principal Scientist, and Chief Scientist at Climate Central, a non-profit dedicated to increasing public understanding and awareness of climate change. Dr. Duffy has held academic posts at Stanford University, the University of California at Merced, and at the Carnegie Institution for Science. In 2003 he became the founding director of a University of California system-wide institute for collaborative research into the societal impacts of climate change. Dr. Duffy's areas of expertise include mathematical modeling of climate, downscaling of climate projections, quantifying uncertainty in projections of future climate, and understanding societal impacts of climate change. He has over 70 peer-reviewed publications in climate science, atomic physics, and astrophysics. Dr. Duffy has contributed to the IPCC in several roles, and in 2008 he won the LLNL Science and Technology Award and the United Nations Association Global Citizen Award.

Selected (Recent) Publications

Duffy, P. B., and C. Tebaldi, 2012. Increasing prevalence of extreme summer temperatures in the U.S., Climatic Change Letters, 111 (2): 487 DOI: 10.1007/s10584-012-0396-6.

Mote, P., L. Brekke, P. B. Duffy, and E. Maurer, 2010. "Guidelines for constructing climate scenarios. EOS, Transcations of the American Geophysical Union. 92(31), 257, doi: 10.1029/2011EO310001.

Wehner, M. F., G. Bala, P. B. Duffy, A. M. Mirin and R. Romano, 2010. "Towards direct simulation of future tropical cyclone statistics in a high resolution global atmospheric model," Advances in Meteorology, Volume 2010, Article ID 915303, doi: 10.1155/2010/915303.

Wehner, M. F., R. L. Smith, G. Bala, and P. B. Duffy, 2010. The effect of horizontal resolution on simulation of very extreme U.S. precipitation events, Climate Dynamics, DOI 10.1007/s00382-009-0656-y

Ferguson, I.M., J. A. Dracup, P. B. Duffy, P. Pegion, S. Schubert, 2010. Influence of SST Forcing on Stochastic Characteristics of Simulated Precipitation and Drought, Journal of Hydrometeorology 11:3, 754-769

Loarie, S., P. B. Duffy, H. Hamilton. G. Asner, C. Field, and D. Ackerly, 2009. The velocity of climate change, Nature, 462, 1052-1055, doi: 10.1038/nature08649.

Bala, G., P. B. Duffy, and K. Taylor, 2008. Impact of Geoengineering Schemes on the Global Hydrological Cycle. Proceedings of the National Academy of Sciences, 105, 7664–7669.

Bonfils, C., P. B. Duffy, B. Santer, D. Lobell, Thomas J. Phillips, T.M.L. Wigley, Charles Doutriaux, 2007. Identification of external influences on temperatures in California, Climatic Change.

Maurer, E.P., L. Brekke, T. Pruitt, and P. B. Duffy, 2007, Fine-resolution climate change projections enhance regional climate change impact studies, Eos, Transactions, American Geophysical Union, 88(47), 504 (online)

Duffy, P. B., C. Bonfils, D. Lobell, 2007: Interpreting Recent Temperature Trends in California, Eos, Transactions, American Geophysical Union, 88, NO. 41, doi: 10.1029/2007EO41000.

Maurer, E. P., I. T. Stewart, C. Bonfils, P. B. Duffy, and D. Cayan 2007, Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada, J. Geophys. Res., 112, D11118, doi: 10.1029/2006JD00808.

"Climate Action Team Report to the Governor and Legislature," available at Contributing author.

"Our changing climate: Assessing the Risks to California" A summary report from the California Climate Change Center CEC-500-2006-077. Contributing author.

Cayan, D., E. Maurer, M. Dettinger, M. Tyree, K. Hayhoe, C. Bonfils, P. Duffy, and B. Santer, Climate Change Scenarios for California; appendix to the California Energy Commission report # CEC-500-2005-203-SF, available at

Duffy, P. B., R. W. Arritt, J. Coquard, W. Gutowski, J. Han, J. Iorio, J. Kim, L-R Leung, J. Roads, E. Zeledon, 2006. Simulations of present and future climates in the western U.S. with four nested regional climate models, J. Climate, Vol. 19, No. 6, pp. 873-895.

Coquard, J., P. B. Duffy, and K. E. Taylor, 2004: Present and future surface climate in the western U.S. as simulated by 15 global climate models, Climate Dynamics, vol. 23, pp. 455-472.

Duffy, P. B., B. Govindasamy, J. Milovich, K. Taylor, and S. Thompson, 2003: High Resolution Simulations of Global Climate, Part 1: Present Climate. Climate Dynamics, 21, 371-390, 2003.

Govindasamy, B., P. B. Duffy, and J. Coquard 2003: High Resolution Simulations of Global Climate, Part 2: Effects of Increased Greenhouse Gases. Climate Dynamics, 21, 391-404, 2003.

Govindasamy, B., K. Caldeira and P. B. Duffy, Geoengineering Earth's radiation balance to mitigate climate change from a quadrupling of CO2, Global & Planetary Change. 37(1-2): 157-168, 2003.

Govindasamy, B., S. Thompson, P. B. Duffy, and K. Caldeira, 2002. Impact of climate stabilization schemes on the terrestrial biosphere, Geophys. Res. Lett. 29 (22): 2061.

Duffy, P. B., C. Doutriaux, I. Fodor, and B. Santer, 2001. Effect of Missing Data on Estimates of Near-Surface Temperature Change Since 1900, J. Climate, 14, 2809-2814.

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