Staff

• Scientific Director, Palo Alto Office and Senior Research Scientist
• Email: pduffy@climatecentral.org

Dr. Duffy comes to Climate Central from the Lawrence Livermore National Laboratory, where he was a physicist for 22 years. He is the founder and director of the University of California Institute for Research on Climate Change and its Societal Impacts, and an Adjunct Associate Professor at UC Merced. Dr. Duffy holds a Ph.D. in applied physics from Stanford University.

Like Dr. Moore, Dr. Duffy is a member of the Nobel-honored Intergovernmental Panel on Climate Change (IPCC). He has published over 50 peer-reviewed papers on many aspects of climate science. His recent work has focused on increasing the spatial resolution of climate projections, to make them more suitable for assessing potential societal impacts of climate change.

Publications

• M. F. Wehner, R. L. Smith, G. Bala and P. Duffy, The effect of horizontal resolution on simulation of very extreme US precipitation events in a global atmosphere model, Climate Dynamics, Vol. 34, pp 241-247, February 2010.
• S. Loarie, P. Duffy, H. Hamilton, C. Field, D. Ackerly, The Velocity of Climate Change, Nature, 462, 1052-1055, 2009.
• P. B. Duffy, B D Santer, and T. M. L. Wigley, 2009: Solar Variability Does not Explain 20th Century Warming, Physics Today, January, 2009, pp 48-49.
• G. Bala, P. B. Duffy, and K. Taylor, Impact of Geoengineering Schemes on the Global Hydrological Cycle, Proceedings of the National Academy of Sciences, 2008.
• C. Bonfils, P. B. Duffy, B. Santer, D. Lobell, Thomas J. Phillips, T.M.L. Wigley, Charles Doutriaux, Identification of external influences on temperatures in California, Climatic Change, December 19, 2007.
• C. Bonfils, P. B. Duffy, and D. Lobell: 2007, "Comment on ‘Methodology and Results of Calculating Central California Surface Temperature Trends: Evidence of a Human-Induced Climate Change?’’, J. Climate, 20, 4486-4498.
• E.P. Maurer, 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
• P. B. Duffy, C. Bonfils, D. Lobell, 2007: Interpreting Recent Temperature Trends in California, Eos, Transactions, American Geophysical Union, 88, NO. 41, doi:10.1029/2007EO410001.
• E. P. Maurer, 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:10.1029/2006JD008088.
• “Climate Action Team Report to the Governor and Legislature”. One of many authors. “Our changing climate: Assessing the Risks to California” A summary report from the California Climate Change Center CEC-500-2006-077. One of many contributors.
• K.L. Cole, K. Ironside, S. Arundel, P. Duffy, and J. Shaw. 2007. Modeling future plant distributions on the Colorado Plateau: An example using Pinus edulis. In, The Colorado Plateau III, C. van Riper III and M. Sogge (eds), The University of Arizona Press.
• D. B. Lobell, C. Bonfils, and P. B. Duffy (2007), Climate change uncertainty for daily minimum and maximum temperatures: A model inter-comparison, Geophys. Res. Lett., 34, L05715, doi:10.1029/2006GL028726.
• D. B. Lobell, G. Bala, C. Bonfils, and P.B. Duffy. 2006. Potential bias of model projected greenhouse warming in irrigated regions. Geophysical Research Letters 33:L13709, doi:10.1029/2006GL026770.
• D. B. Lobell, G. Bala, and P.B. Duffy. 2006. Biogeophysical impacts of cropland management changes on climate. Geophysical Research Letters 33:L06708 10.1029/2005GL025492.
• S. J. Kim, T. Crowley, P. B. Duffy, and G. Bala, 2007. High-Resolution Climate Simulation of the Last Glacial Maximum, Climate Dynamics 10.1007/s00382-007-0332-z.
• A. Gettelman, W. D. Collins, E. J. Fetzer, A. Eldering, F. W. Irion, P. B. Duffy and G. Bala, 2006: A Satellite Climatology of Upper Tropospheric Relative Humidity and Implications for Climate, J. Climate, 19, pp. 6104-6121.
• E. Maurer, S. Gibbard, and P. B. Duffy, Amplification of streamflow impacts during El Nino conditions in California under a warming climate, 2006: Geophys Res Lett., Vol. 33, No. 2, L02707 10.1029/2005GL025100.
• D. Cayan, 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.
• E. Maurer and P. B. Duffy, Uncertainty in Projections of Hydrologic Impacts of Climate Change in California, Geophys. Res. Lett, 32, doi 10.1029/2004GL021462, 2005.
• P. B. Duffy, R. W. Arritt, J. Coquard, W. Gutowski, J. Han, J. Iorio, J. Kim, L-R Leung, J. Roads, E. Zeledon, 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, 2006.
• N. S. Grumet, P. B. Duffy, M. E. Wickett, K. Caldeira, and R. B. Dunbar, Intrabasin Comparison of Surface Radiocarbon Levels in the Indian Ocean Between Coral Records and Three-Dimension Global Ocean Models, Global Biogeochemical Cycles, 19, 23 April, 2005.
• J. Coquard, 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.
• J. Iorio, P. B. Duffy. M. Khairoutdinov, and D. Randall, 2004: Effect of model resolution and subgrid scale physics on daily precipitation in the continental United States; Climate Dynamics, 23, 243-258, 2004.
• J. L. Bell, L. C. Sloan, J. Revenaugh and P. B. Duffy, 2003: Evaluation of Northern Hemisphere natural climate variability in multiple temperature reconstructions and global climate model simulations. Global and Planetary Change, 37, Issues 1-2, 10 June 2003, pp. 19-31.
• P. B. Duffy, 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.
• B. Govindasamy, 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.
• P. B. Duffy, M. E. Wickett, and K. Caldeira, Effect of horizontal grid resolution on the near-equilibrium solution of a global ocean/sea ice model, J. Geophys. Res, 108(C6): 3189, 2003.
• B. Govindasamy, 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.
• M. E. Wickett, K. Caldeira, and P. B. Duffy, Effect of horizontal grid resolution on simulations of oceanic CFC-11 uptake and direct injection of anthropogenic CO2, J. Geophys. Res. 108, No. C6, 3189, 10.1029/2001JC001130, 14 June 2003.
• B. Govindasamy, S. Thompson, P. B. Duffy, and K. Caldeira, Impact of climate stabilization schemes on the terrestrial biosphere, Geophys. Res. Lett.29 (22): 2061, 2002.
• K. Caldeira, M. E. Wickett and P. B. Duffy, Depth, radiocarbon, and the effectiveness of direct CO2 injection as an ocean carbon sequestration strategy, Geophysical Research Letters. 29(16):1766, 2002
• M. A. Snyder, J. L. Bell, L. C. Sloan, P. B. Duffy, Climate responses to a doubling of atmospheric carbon dioxide since the preindustrial era for a climatically vulnerable region, Geophys. Res. Lett, 29, 29(11), 1514, doi:10.1029/2001GL014431 June, 2002.
• P. B. Duffy, C. Doutriaux, I. Fodor, and B. Santer, Effect of Missing Data on Estimates of Near-Surface Temperature Change Since 1900, J. Climate, 14, 2809-2814, 2001.
• B. Govindasamy, K. E. Taylor, P. B. Duffy, B. J. Santer, A. S. Grossman, and K. E. Grant, Limitations of the equivalent CO2 approximation in climate change simulations; J. Geophys. Res., 106, p. 22593-22603, 2001.
• B. J. McAvaney et al, “Model Evaluation”, in Climate Change: The Scientific Basis; IPCC Third Assessment Report, Cambridge University Press, 2001.
• P. B. Duffy, M. Eby, and A.J. Weaver, Climate Model Simulations of Effects of Increased Atmospheric CO2 and Loss of Sea Ice on Ocean Salinity and Tracer Uptake, J. Climate, 14, 520-532, 2001.
• B. Govindasamy, P. B. Duffy, and K. Caldeira, Land Use Changes and Northern Hemisphere Cooling, Geophys. Res. Lett, 28, 291-294, 2001.
• A. J. Weaver, M. Eby, E. C. Wiebe, C. M. Bitz, P. B. Duffy, T. L. Ewen, A. F. Fanning, M. M. Holland, A. MacFadyen, H. D. Matthews, K. J. Meissner, O. Saenko, A. Schmittner, H. Wang and M. Yoshimori, 2001: The UVic Earth System Climate Model: Model description, climatology and application to past, present and future climates. Atmosphere-Ocean, 38. 271-301, 2000.
• M. E. Wickett, P.B. Duffy, and G. Rodrigue, A reduced grid for a parallel global ocean general circulation model, Ocean Modelling, 2, 85-107, 2000.
• T. Guilderson, K. Caldeira, and P. B. Duffy, Radiocarbon as a diagnostic tracer in ocean and carbon cycle modeling, Global Biogeochemical Cycles, 14, 887-902, 2000. J. Bell, P. B. Duffy, C. Covey, and L. Sloan, Analysis of Temperature Variability in Sixteen Climate Model Simulations, Geophysical Research Letters, 27, 261-264, 2000.
• M. I. Hoffert, K. Caldeira, C. Covey, P.B. Duffy, B. Santer, Solar variability and the Earth’s climate, Nature, 401, 764-764, 1999.
• P. B. Duffy, J. Bell, C. Covey, and L. Sloan, Effect of flux adjustments on temperature variability in coupled models, Geophysical Research Letters, 27, 763-766, 2000.
• K. Caldeira and P.B. Duffy, The role of the Southern Ocean in uptake and storage of anthropogenic carbon dioxide, Science, 287, 620-622, 2000.
• A. J. Weaver, P. B. Duffy, M. Eby, and E.C. Wiebe, On the evaluation of ocean and climate models using present-day forcing, Atmosphere-Ocean, 38, 271-201, 2000.
• P. B. Duffy, M. Eby, and A.J. Weaver, Effects of Sinking of Salt Rejected During Formation of Sea Ice on Results of a Global Ocean-Atmosphere-Sea Ice Climate Model, Geophys. Res. Lett., 26, 1739-1742, 1999.
• M. I. Hoffert, K. Caldeira, C. Covey, P. B. Duffy, B. Santer, Solar variability and the Earth’s climate, Nature, 401, 764-764, 1999.
• P. B. Duffy and K. Caldeira, Sensitivity of Simulated Salinities in a Three-Dimensional Ocean General Circulation Model to Vertical Mixing of Destabilizing Surface Fluxes, Climate Dynamics, 15, 81-88, 1999.
• B. Govindasamy, M. F. Wehner, C. R. Mechoso, and P. B. Duffy, The Influence of a Land Surface Scheme on Simulated Climate by LLNL/UCLA AGCM, Global and Planetary Change, 20, 67-86, 1999.
• K. Caldeira, G. H. Rau, and P. B. Duffy, Predicted oceanic degassing of radiocarbon and increase in atmospheric radiocarbon content, Geophys. Res. Lett.., 25, 3811-3814, 1998.
• K. Caldeira, and P. B. Duffy, Sensitivity of simulated CFC-11 distributions in a global ocean model to the treatment of salt rejected during sea-ice formation, Geophys. Res. Lett, 25, 1003-1006, 1998.
• Wehner, M.F., P.G. Eltgroth, A.A. Mirin, P.B. Duffy, K.G. Caldeira, J.H. Bolstad, H. Wang, C.M. Matarazzo, U.E. Creach, 1997, Comprehensive Climate System Modeling on Massively Parallel Computers, in Mission Earth: Modeling and Simulation for a Sustainable Global System, edited by M.G. Clymer and C. R. Mechoso, the Society for Computer Simulation International, 37-42, 1998.
• P. B. Duffy, and K. Caldeira, Sensitivity of Simulated Salinity in a Three-dimensional Ocean Model to Upper-Ocean Transport of Salt From Sea-Ice Formation,Geophys. Res. Lett. 24, 1323-1326, 1997.
• P. B. Duffy, K. Caldeira, J. Selvaggi, and M. Hoffert, Effect of Subgrid Scale Mixing Parameterizations on Simulated Distributions of Natural 14C, Temperature, and Salinity in a Three-Dimensional Ocean General Circulation Model, J. Phys. Oceanogr, 27, 498-523, 1997.
• G. Perry, P. B. Duffy, and N. Miller, An Extended Dataset of River Discharges for Validation of Climate Models, J. Geophys. Res., 101, 21,339-21,349, 1996.
• P. B. Duffy, D. Eliason, A. J. Bourgeois, and C. Covey, Simulation of Bomb Radiocarbon in Two Ocean General Circulation Models, J. Geophys. Research, 100, 22,545-22,565, 1995. P. B. Duffy, and K. Caldeira, A Three-Dimensional Model Calculation of Ocean Uptake of Bomb 14C and Implications for the Global Budget of Bomb 14C, Global Biogeochemical Cycles, 9, 373-375, 1995.
• P. B. Duffy, P. Eltgroth, A. J. Bourgeois, and K. Caldeira, Effect of Improved Subgrid Scale Transport of Tracers on Uptake of Bomb Radiocarbon in the GFDL Ocean General Circulation Model, Geophysical Review Letters, 22, 1065-1068, 1995.
• A. A. Mirin, J. J. Ambrosiano, J. H. Bolstad, A. J. Bourgeois, J. C. Brown, B. Chan, W. P. Dannevik, P. B. Duffy, P. G. Eltgroth, C. Matarazzo, and M. F. Wehner, Climate System Modeling using a Domain and Task Decomposition Message-Passing Approach, Computer Physics Communications, 84, 278-296, 1994.
• J. M. Wilcox, P. B. Duffy, K. H. Schatten, L. Svalgaard, P. S. Scherrer, W. O. Roberts, and R. Olson, Interplanetary Magnetic Field Polarity and the Size of Low Pressure Troughs near 180 deg. W longitude”, Science, 204, p. 60, 1979.