Dear Mr. President,
You take office for the second time at a critical moment. As you may know, the U.S. has just recorded the hottest year in its history, beating the old mark by a full degree; the same year that saw the deep Midwest drought, and the fury of Hurricane Sandy, also witnessed the rapid and unprecedented melt of the Arctic ice pack.
If we are to restrain the rise in the planet’s temperature, it will require strong action from, among others, the planet’s sole superpower. Some of that work will be difficult, requiring the cooperation of Congress. But other steps are relatively easy.
Eighteen months ago some of us wrote you about the proposed Keystone XL tar sands pipeline, explaining why in our opinion its construction ran counter to both national and planetary interests. Nothing that has happened since has changed that evaluation; indeed, the year of review that you asked for on the project made it clear exactly how pressing the climate issue really is.
We hope, as scientists, that you will demonstrate the seriousness of your climate convictions by refusing to permit Keystone XL; to do otherwise would be to undermine your legacy.
Thank you,James Hansen Research Scientist The International Research Institute for Climate and Society The Earth Institute, Columbia University Ralph Keeling Director Scripps CO2 Program Scripps Institution of Oceanography John Harte Professor of Ecosystem Sciences University of California Jason E. Box Professor Byrd Polar Research Center John Abraham Associate Professor, School of Engineering University of St. Thomas Ken Caldeira Senior Scientist. Department of Global Ecology Carnegie Institution Michael MacCracken Chief Scientist for Climate Change Programs Climate Institute Michael E. Mann Professor of Meteorology Director, Earth System Science Center The Pennsylvania State University James McCarthy Alexander Agassiz Professor of Biological Oceanography Harvard University Michael Oppenheimer Albert G. Milbank Professor of Geosciences and International Affairs Woodrow Wilson School and Department of Geosciences Princeton University Raymond T. Pierrehumbert Louis Block Professor in the Geophysical Sciences The University of Chicago Richard Somerville Distinguished Professor Emeritus and Research Professor Scripps Institution of Oceanography George M. Woodwell Founder, Director Emeritus, and Senior Scientist Woods Hole Research Center Mauri Pelto Department of Environmental Science Nichols College David Archer Professor, Department of Geophysical Sciences The University of Chicago Dr. Ted Scambos Lead Scientist, National Snow and Ice Data Center University of Colorado at Boulder Terry L. Root Senior Fellow Stanford University Alan Robock, Professor II Distinguished Professor, Department of Environmental Sciences Rutgers University