---
title: Keystone XL Scientists Letter
date: 2012-01-15T22:47:01Z
modified: 2014-01-15T22:48:21Z
permalink: "https://350.org/kxl-scientist-letter/"
type: page
status: publish
excerpt: ""
wpid: 31615
author: The 350.org Team
---

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_