An Open Letter Regarding Climate Change From Concerned Members of the U.S. National Academy of Sciences

Welcome to ResponsibleScientists.org

On September 20, 2016, 378 members of the National Academy of Sciences, including 30 Nobel laureates, published an open letter to draw attention to the serious risks of climate change. The letter warns that the consequences of opting out of the Paris agreement would be severe and long-lasting for our planet’s climate and for the international credibility of the United States.

A full list of signers, including some who signed after September 20, 2016, follows the text of the letter.

An Open Letter Regarding Climate Change From Concerned Members of the U.S. National Academy of Sciences

Human-caused climate change is not a belief, a hoax, or a conspiracy. It is a physical reality. Fossil fuels powered the Industrial Revolution. But the burning of oil, coal, and gas also caused most of the historical increase in atmospheric levels of heat-trapping greenhouse gases. This increase in greenhouse gases is changing Earth’s climate.

Our fingerprints on the climate system are visible everywhere. They are seen in warming of the oceans, the land surface, and the lower atmosphere. They are identifiable in sea level rise, altered rainfall patterns, retreat of Arctic sea ice, ocean acidification, and many other aspects of the climate system. Human-caused climate change is not something far removed from our day-to-day experience, affecting only the remote Arctic. It is present here and now, in our own country, in our own states, and in our own communities.

During the Presidential primary campaign, claims were made that the Earth is not warming, or that warming is due to purely natural causes outside of human control. Such claims are inconsistent with reality.

Others argued that no action is warranted until we have absolute certainty about human impacts on climate. Absolute certainty is unattainable. We are certain beyond a reasonable doubt, however, that the problem of human-caused climate change is real, serious, and immediate, and that this problem poses significant risks: to our ability to thrive and build a better future, to national security, to human health and food production, and to the interconnected web of living systems.

The basic science of how greenhouse gases trap heat is clear, and has been for over a century. Ultimately, the strength of that basic science brought the governments of the world to Paris in December 2015. They went to Paris despite pronounced differences in systems of government, in national self-interest, in culpability for past emissions of greenhouse gases, and in vulnerability to future climate change. The leaders of over 190 countries recognized that the problem of human-caused climate change is a danger to present and future citizens of our planet. They made national commitments to address this problem. It was a small but historic and vital first step towards more enlightened stewardship of Earth’s climate system.

From studies of changes in temperature and sea level over the last million years, we know that the climate system has tipping points. Our proximity to these tipping points is uncertain. We know, however, that rapid warming of the planet increases the risk of crossing climatic points of no return, possibly setting in motion large-scale ocean circulation changes, the loss of major ice sheets, and species extinctions. The climatic consequences of exceeding such thresholds are not confined to the next one or two electoral cycles. They have lifetimes of many thousands of years.

The political system also has tipping points. Thus it is of great concern that the Republican nominee for President has advocated U.S. withdrawal from the Paris Accord. A “Parexit” would send a clear signal to the rest of the world: "The United States does not care about the global problem of human-caused climate change. You are on your own." Such a decision would make it far more difficult to develop effective global strategies for mitigating and adapting to climate change. The consequences of opting out of the global community would be severe and long-lasting – for our planet’s climate and for the international credibility of the United States.

The United States can and must be a major player in developing innovative solutions to the problem of reducing emissions of greenhouse gases. Nations that find innovative ways of decarbonizing energy systems and sequestering CO2 will be the economic leaders of the 21st century. Walking away from Paris makes it less likely that the U.S. will have a global leadership role, politically, economically, or morally. We cannot afford to cross that tipping point.

The following signers of this letter do so as individual NAS members and not on behalf of the NAS itself or their Institutions.

SIGNED BY:

• Benjamin D. Santer, Member, National Academy of Sciences
• Kerry A. Emanuel, Massachusetts Institute of Technology
• George B. Field, Harvard University
• Ray Weymann, Carnegie Institution for Science Emeritus
• Peter C. Agre, Johns Hopkina Malaria Research Institute
• Bruce Alberts, University of California San Francisco
• Thomas D. Albright, The Salk institute for Biological Studies
• Richard M. Amasino, University of Wisconsin-Madison
• Jim Anderson, Harvard University
• Phillip W. Anderson, Princeton University
• Roger Angel, University of Arizona
• Luc E. Anselin, University of Chicago
• Fred Anson, California Institute of Technology
• David Arnett, Univerity of Arizona
• Mary T. Kalin Arroyo, University of Chile
• Greg Asner, Carnegie Institution for Science
• Sir Michael Atiyah, University of Edinburgh
• Tanya M. Atwater, University of California Santa Barbara
• Francisco J. Ayala, University of California Irvine
• George Backus, University of California San Diego
• Neta Bahcall, Princeton University
• Steven Balbus, University of Oxford
• David Baltimore, California Institute of Technology
• Allen Bard, University of Texas
• Sir David Baulcombe, University of Cambridge
• Adriaan Bax, Member, National Academy of Sciences
• Barry J. Beaty, Colorado State University
• Anthony Bebbington, Clark University
• Michael Bender, Princeton University
• Charles L. Bennett, Johns Hopkins University
• Michael V.L. Bennett, Albert Einstein College of Medicine
• Jeffrey L. Bennetzen, University of Georgia
• John Bercaw, California Institute of Technology
• May R. Berenbaum, University of Illinois at Urbana-Champaign
• Howard Berg, Harvard University
• Robert Bergman, University of California Berkeley
• Joseph Berry, Carnegie Institution for Science
• Jacques E. Blamont, Centre National d' Etudes Spatiales
• Roger Blandford, Stanford University
• Michael R Botchan, University of California Berkeley
• Ed A. Boyle, Massachusetts Institute of Technology
• Daniel Branton, Member, National Academy of Sciences
• Winslow Briggs, Carnegie Institution for Science
• Steven P. Briggs, University of California San Diego
• Wallace Broecker, Columbia University
• James H. Brown, University of New Mexico
• Patrick O. Brown, Stanford University School of Medicine 
• Axel T. Brunger, Stanford University
• Douglas W. Burbank, University of California Santa Barbara
• E. Margaret Burbidge, University of California San Diego Emerita
• Adam Burrows Princeton University
• John Cairns, Virginia Polytechnic Institute and State University
• Mark A. Cane, Columbia University
• Claude Canizares, Massachusetts Institute of Technology
• Marian Carlson, Columbia University
• John Carlson, Yale University
• Stephen Carpenter, University of Wisconsin-Madison
• James C. Carrington, Oregon State University 
• Sean B. Carroll, University of Wisconsin-Madison
• Emily A. Carter, Princeton University
• Katherine Cashman, University of Bristol
• Juan Carlos Castilla, Pontificia Universidad Católica de Chile
• Anny Cazenave, Centre National d'Etudes Spatiales
• Thure E. Cerling, University of Utah
• Sylvia T. Ceyer, Massachusetts Institute of Technology
• Martin Chalfie, Columbia University
• F. Stuart Chapin, University of Alaska
• Roger Chevalier, University of Virginia
• Steven Chu, Stanford University
• Ralph Cicerone, Professor Emeritus, University of California
• David E. Clapham, Harvard Medical School
• George Clark, Massachusetts Institute of Technology
• Michael T. Clegg, University of California Irvine
• Marshall Cohen, California Institute of Technology
• Claude Cohen-Tannoudji, Laboratoire Kastler Brossel
• Jonathan J. Cole, Cary Institute of Ecosystem Studies
• Rita R. Colwell, University of Maryland
• Karen S. Cook, Stanford University
• Richard M. Cowling, Nelson Mandela Metropolitan University
• James Cronin, University of Chicago
• Maureen Cropper, University of Maryland
• Paul J. Crutzen, Max Planck Institute for Chemistry
• Roy Curtiss III, University of Florida
• Gretchen Daily, Stanford University
• G. Brent Dalrymple, Oregon State University
• Jeffrey L. Dangl, University of North Carolina 
• Seth A. Darst, The Rockefeller University
• Sir Partha Dasgupta, University of Cambridge
• Earl W. Davie, University of Washington
• Russ E. Davis, University of California San Diego
• Marc Davis, University of California Berkeley
• Ruth DeFries, Columbia University
• Johann Deisenhofer, University of Texas Southwestern Medical Center
• Edward F. DeLong, University of Hawaii Manoa
• David L. Denlinger, Ohio State University
• George Denton, University of Maine
• Donald DePaolo, Univerity of California Berkeley
• Bob Dickinson, University of Texas
• Rodolfo Dirzo, Stanford University
• Michael J. Donoghue, Yale University
• Russell F. Doolittle, University of California San Diego
• Dennis A. Dougherty, California Institute of Technology
• John E. Dowling, Harvard University
• Bruce Draine, Princeton University
• Alan Dressler, Carnegie Institution for Science
• Thomas Dunne, University of California Santa Barbara
• Joseph R. Ecker, Member, National Academy of Sciences
• R. Lawrence Edwards, University of Minnesota
• Paul Ehrlich, Stanford University
• John M. Eiler, California Institute of Technology
• David Eisenberg, University of California Los Angeles
• Richard Eisenberg, University of Rochester
• S. Walter Englander, University of Pennsylvania School of Medicine 
• W. Gary Ernst, Stanford University
• Mark Estelle, University of California San Diego
• James A. Estes, University of California Santa Cruz
• Paul Falkowski, Rutgers University
• Nina V. Fedoroff, Pennsylvania State University Emerita
• Juli Feigon, University of California Los Angeles
• Joseph Felsenstein, University of Washington
• Alex Filippenko, University of California Berkeley
• Gerald D. Fischbach, Simons Foundation, Chief Scientist
• Edmond H. Fischer, University of Washington
• Donald Forsyth, Brown University
• Stewart Fotheringham, Arizona State University
• Joachim Frank, Columbia University
• Janet Franklin, Arizona State University
• Wendy Freedman, University of Chicago
• Katherine H. Freeman, Pennsylvania State University
• Perry Allen Frey, University of Wisconsin-Madison
• Carl Frieden, Washington University School of Medicine 
• Margaret T. Fuller, Stanford University
• Douglas J. Futuyma, Stony Brook University
• Fred H. Gage, Salk Institute for Biological Research
• Chris Garrett, University of Victoria
• Neil Gehrels, Member, National Academy of Sciences
• Reinhard Genzel, Max-Planck-Institut für Extraterrestrische Physik
• Howard Georgi, Harvard University
• Charles Gilbert, The Rockefeller University
• Sheldon Glashow, Boston University
• Roy Glauber, Harvard University
• Alexander N. Glazer, University of California Berkeley
• Peter H. Gleick, Pacific Institute
• Stephen P. Goff, Columbia University
• Robert B. Goldberg, University of California Los Angeles
• Peter Goldreich, Institute for Advanced Study, Princeton
• Michael Goodchild, University of California Santa Barbara
• Richard Goody, Harvard University
• Fred Gould, North Carolina State University
• Harry Gray, California Institute of Technology
• Paul Greengard, Rockefeller University
• Diane E. Griffin, Johns Hopkins Bloomberg School of Public Health
• David Gross, University of California Santa Barbara
• Charles G. Gross, Princeton University
• Carol A. Gross, University of California San Francisco
• Timothy Grove, Massachusetts Institute of Technology
• Robert H. Grubbs, California Institute of Technology
• Jim Gunn, Princeton University
• Sarah Hake, Agricultural Research Service
• Alexander Halliday, University of Oxford
• Jim Hansen, Columbia University
• Susan Hanson, Clark University
• Serge Haroche, College de France
• Fiona A. Harrison, California Institute of Technology
• Stanley Hart, Woods Hole Oceanographic Institution
• Daniel L. Hartl, Harvard University
• Dennis Hartmann, University of Washington
• Robert Haselkorn, The University of Chicago
• Alan Hastings, University of California Davis
• Robert M. Hauser, University of Wisconsin-Madison
• Kristen Hawkes, University of Utah 
• Stephen Hawking, Cambridge University
• Wick C. Haxton, Univerity of California Berkeley
• John Hayes, Woods Hole Oceanographic Institution
• Martha P. Haynes, Cornell University
• Timothy Heckman, Johns Hopkins University
• Carl Heiles, University of California Berkeley
• Lars Hernquist, Harvard University
• Dudley Herschbach, Harvard University
• John G. Hildebrand, University of Arizona
• Bertil Hille, University of Washington 
• David M. Hillis, University of Texas
• Sarah Hobbie, University of Minnesota
• Bert Hoelldobler, Arizona State University
• Paul F. Hoffman, University of Victoria
• Albrecht W. Hofmann, Max Planck Institute for Chemistry
• Tomas Hökfelt, Karolinska Institutet 
• Sir Brian Hoskins, Imperial College London & University of Reading
• Michael Hout, New York University 
• Andre T. Jagendorf, Cornell University
• Christopher S. Jencks, Harvard University 
• Daniel H. Janzen, University of Pennsylvania
• David C. Jewitt, University of California Los Angeles
• J.R. Jokipii, University of Arizona
• Tom Jordan, University of Southern California
• Jean Jouzel, Laboratoire des Sciences du Climate et de l'Environnement
• William A. Jury, University of California Riverside
• H. Ronald Kaback, University of California Los Angeles
• Thomas Kailath, Stanford University
• Peter M. Kareiva, University of California Los Angeles
• David Karl, University of Hawaii
• Harvey Karten, Professor Emeritus, University of California San Diego
• Guinevere Kauffmann, Max Planck Institute for Astrophysics
• Steve A. Kay, University of Southern California
• Paul Kay, International Computer Science Institute
• Peter Kelemen, Columbia University
• Kenneth Kellermann, National Radio Astronomy Observatory
• Donald Kennedy, Stanford University
• Charles Kennel, University of California San Diego
• Robert C. Kennicutt, Cambridge University
• Wolfgang Ketterle, Massachusetts Institute of Technology
• Gurdev S. Khush, University of California Davis 
• Margaret Kidwell, University of Arizona
• Susan W. Kieffer, University of Illinois at Urbana-Champaign
• Peter S. Kim, Stanford University
• Patrick V. Kirch, University of California Berkeley
• Margaret Kivelson, University of California Los Angeles
• Daniel Kleppner, Massachusetts Institute of Technology
• Catherine L. Kling, Iowa State University
• Judith P. Klinman, University of California Berkeley
• Eric I. Knudsen, Stanford University School of Medicine
• Brian Koblika, Stanford University School of Medicine
• M.A.R. Koehl, Univerity of California Berkeley
• David Kohlstedt, University of Minnesota
• Sir Hans Kornberg, Boston University
• John Krebs, University of Oxford
• Shrinivas Kulkarni, California Institute of Technology
• J. Clark Lagarias, University of California Davis
• Kurt Lambeck, Australian National University
• Eric Lambin, Stanford University
• Arthur Landy, Brown University
• Charles H. Langmuir, Harvard University
• Brian A. Larkins, University of Nebraska, Lincoln
• John H. Law, University of Arizona Emeritus
• Sir John Lawton, Former Chief Executive, UK Natural Environment Research Council
• Yuan Lee, Academica Sinica Taiwan
• Richard E. Lenski, Michigan State University
• Estella Leopold, University of Washington
• Simon Levin, Princeton University
• Michael Levitt, Stanford University School of Medicine
• Gene E. Likens, Cary Institute of Ecosystem Studies
• Laszlo Lorand, Feinberg Medical School Northwestern University Emeritus
• C. Owen Lovejoy, Kent State University
• Jane Lubchenco, Oregon State University
• Jonathan I. Lunine, Cornell University
• Michael Lynch, Indiana University
• Akin Mabogunje, Foundation for Development and Environmental Initiatives
• Trudy Mackay, North Carolina State University
• Anthony P. Mahowald, University of Chicago
• Syukuro Manabe, Princeton University
• Charles Manski, Northwestern University
• Joyce Marcus, University of Michigan
• Rudolph A. Marcus, California Institute of Technology
• Susan Marqusee, University of California Berkeley
• Douglas S. Massey, Princeton University
• Pamela A. Matson, Stanford University
• Rowena G. Matthews, University of Michigan Emerita
• Michel G. Mayor, University of Geneva
• Bonnie J. McCay, Rutgers University
• Richard McCray, University of Colorado
• Bruce S. McEwen, Rockefeller University
• Fred McLafferty, Cornell University
• Jim McWilliams, University of California Los Angeles
• Jerrold Meinwald, Cornell University
• Jerry M. Melillo, Marine Biological Laboratory, Woods Hole
• Henry J. Melosh, Purdue University
• Sabeeha Merchant, University of California Los Angeles
• Joachim Messing, Rutgers University
• Mario Molina, University of California San Diego
• Harold Mooney, Stanford University
• Peter B. Moore, Yale University
• James M. Moran, Member, National Academy of Sciences
• Nancy Moran, University of Texas
• M. Granger Morgan, Carnegie Mellon University
• Ellen S. Mosley-Thompson, Ohio State University
• Walter Munk, University of California San Diego
• Royce Murray, Univeristy of North Carolina
• Sidney Nagel, University of Chicago
• Ramesh Narayan, Harvard University
• Jeremy Nathans, Johns Hopkins University School of Medicine
• Eugene W. Nester, University of Washington
• William T. Newsome, Stanford University
• Richard P. Novick, New York University School of Medicine
• James F. O’Connell, University of Utah
• Paul E. Olsen, Columbia University
• Peter Olson, Johns Hopkins University
• Neil D. Opdyke, University of Florida
• Jeremiah Ostriker, Columbia University
• Sarah Otto, University of British Columbia
• Sir Ronald Oxburgh, Cambridge University
• Stephen Pacala, Member, National Academy of Sciences
• Norman R. Pace, University of Colorado
• Richard D. Palmiter, University of Washington School of Medicine
• Stephen Palumbi, Stanford University
• Joseph Pedlosky, Woods Hole Oceanographic Institution
• Jim Peebles, Princeton University
• Gordon Pettengill, Massachusetts Institute of Technology
• S. George Philander, Princeton University
• William Phillips, Member, National Academy of Sciences
• Dolores R. Piperno, Member, National Academy of Sciences
• Terry Plank, Columbia University
• William H. Press, University of Texas
• Frank Press, Member, National Academy of Sciences
• George W. Preston, Carnegie Institution for Science 
• Peter H. Raven, Missouri Botanical Garden
• Maureen E. Raymo, Columbia University
• Martin Rees, Cambridge University
• Peter Rhines, University of Washington
• Frank Richter, University of Chicago
• Robert E. Ricklefs, University of Missouri
• Lynn M. Riddiford, University of Washington
• George Rieke, University of Arizona
• Marcia Rieke, University of Arizona
• Adam Riess, Johns Hopkins University
• Morton Roberts, National Radio Astronomy Observatory
• Gene E. Robinson, University of Illinois at Urbana-Champaign
• A. Kimball Romney, University of California Irvine
• Michael Rosbash, Brandeis University
• Michael G. Rossmann, Purdue University 
• Mal Ruderman, Columbia University
• Roberta L. Rudnick, University of California Santa Barbara
• Gary Ruvkun, Massachusetts General Hospital
• Roald Sagdeev, University of Maryland
• Pedro A. Sanchez, Columbia University
• David Sandwell, University of California San Diego
• Joshua R. Sanes, Harvard University
• Daniel L. Schacter, Harvard University
• Paul Schechter, Massachusetts Institute of Technology
• Randy W. Schekman, University of California Berkeley
• Hans Joachim Schellnhuber, Potsdam Institute for Climate Impact Research
• David W. Schindler, University of Alberta
• Bill Schlesinger, Cary Institute of Ecosystem Studies
• Johanna Schmitt, University of California Davis
• Robert J. Scholes, University of the Witswatersrand
• Vern L. Schramm, Albert Einstein College of Medicine 
• Julian Schroeder, University of California San Diego
• Gerald Schubert, Universty of California Los Angeles
• Matthew P. Scott, President, Carnegie Institution for Science
• Sara Seager, Massachusetts Institute of Technology
• Ronald R. Sederoff, North Carolina State University
• Jeff Severinghaus, University of California San Diego
• Irwin Shapiro, Harvard University
• Carla J. Shatz, Stanford University
• Peter Shearer, University of California San Diego
• Frank Shu, University of California San Diego
• Kerry Sieh, Nanyang Technological University
• James Simons, Chairman, Simons Foundation
• Norman H. Sleep, Stanford University
• Susan Solomon, Massachusetts Institute of Technology
• Pamela S. Soltis, University of Florida
• Alfred Sommer, Johns Hopkins Bloomberg School of Public Health
• Charles S. Spencer, American Museum of Natural History 
• David Spergel, Princeton University
• Nicholas C. Spitzer, University of California San Diego
• Charles Steidel, California Institute of Technology
• Thomas A. Steitz, Yale University
• Edward Stolper, California Institute of Technology
• Howard A. Stone, Princeton University
• Joan E. Strassmann, Washington University, St. Louis
• Karen B. Strier, University of Wisconsin-Madison 
• Thomas C. Sudhof, Stanford University School of Medicine 
• Timothy Swager, Massachusetts Institute of Technology
• Lynn R. Sykes, Columbia University Emeritus
• Harvey Tananbaum, Member, National Academy of Sciences
• Joseph Taylor, Princeton University
• John Terborgh, Duke University
• Saul A. Teukolsky, Cornell University
• David Hurst Thomas, American Museum of Natural History
• Lonnie Thompson, Ohio State University
• Kip Thorne, Member, National Academy of Sciences
• James M. Tiedje, Michigan State University
• Alar Toomre, Massachusetts Institute of technology
• Scott Tremaine, Institute for Advanced Study
• Susan Trumbore, Max Planck Institute for Biogeochemistry
• James Tumlinson, Pennsylvania State University
• Billie L. Turner, Arizona State University
• Monica G. Turner, University of Wisconsin-Madison
• Anthony Tyson, University of California Davis
• Joan Selverstone, Valentine University of California Los Angeles
• James L. Van Etten, University of Nebraska
• Martha Vaughan, Member, National Academy of Sciences
• Inder Verma, The Salk institute for Biological Studies
• George Veronis, Yale University
• Peter H. von Hippel, University of Oregon
• Gerhard Wagner, Harvard Medical School
• David B. Wake, University of California Berkeley
• David Walker, Columbia University
• John M. Wallace, University of Washington
• E. Bruce Watson, Member, National Academy of Sciences
• Steven Weinberg, University of Texas
• Rainer Weiss, Massachusetts Institute of Technology
• William J. Welch, University of California Berkeley
• Mary Jane West-Eberhard, Smithsonian Tropical Research Institute Emerita
• Simon D.M. White, Max Planck Institute for Astrophysics
• Torsten N. Wiesel, President Emeritus, The Rockefeller University
• Edward O. Wilson, Harvard University
• Robert W. Wilson, Member, National Academy of Sciences
• David Wineland, Member, National Academy of Sciences
• Steven Wofsy, Harvard University
• Richard V. Wolfenden, University of North Carolina 
• Julian Wolpert, Princeton University
• John Wood, Member, National Academy of Sciences
• George M. Woodwell, Woods Hole Research Center
• Stanford E. Woosley, University of California Santa Cruz
• Carl Wunsch, Massachusetts Institute of Technology
• Keith Yamamoto, University of California San Francisco
• Martin Yanofsky, University of California San Diego
• Tilahun Yilma, University of California Davis
• William Young, University of California San Diego
• Mary Lou Zoback, Stanford University
• Maria T. Zuber, Massachusetts Institute of Technology