02/02/2012 01:50 pm ET Updated Apr 03, 2012

Climate Scientists: Calling Out the Cranks

A striking letter just appeared in the Wall Street Journal signed by 38 leading climate scientists. They strongly protest a previous opinion piece titled "No Need to Panic About Global Warming," signed by other scientists of good repute in their fields -- but not in climate science. The 38 co-singers of the new letter don't counsel "panic" but they do state unequivocally that "the world is heating up and humans are primarily responsible."

Ironically, but perhaps not coincidentally, on the next page there appears an opinion piece by Theodore Olsen, a lawyer for the Koch brothers, multibillionaires who fund all manner of right-wing causes -- including climate denial (and some good stuff too, it must be said).

Titled "Obama's Enemies List," this is an astonishing complaint about governmental "McCarthyism," and "tyrannical power," supposedly meant to "oppress" the poor Koch brothers. While not getting too deeply into the Koch business practices here, (OK: Here's one piece, from those "socialists" at Bloomberg, about their bribery and dealings with Iran), we'll just say this is an astonishing whine and leave it at that.

But back to the climate scientists: They aptly note that in many scientific debates, at least a few outlier scientists exist who disagree with the majority opinion. Most of those, however, eventually come to accept the consensus, but some stick it out, curmudgeons for so long that eventually it would be too embarrassing to admit one's error. They note that some researchers held for years that tobacco was really not so bad, and that "there is a retrovirus expert who does not accept that HIV causes AIDS.

Here they must be referring to Peter Duesberg, an otherwise distinguished virologist who became the leading voice of "AIDS denialism," holding that the disease was actually caused by drug abuse and the medications approved to fight HIV disease (which only a little thought, such as about transfusion-associated HIV, renders absurd). No amount of evidence would deter him, or a few others, such as Nobelist Kary Mullis (whose own Nobel-winning work had nothing to do with HIV).

I met both Duesberg and Mullis at a scientific meeting and was stuck by how much they reveled in the attention their statements brought their way. There seemed to be more "abnormal psychology" than real science at play. And I wonder how much of a similar dynamic is at play with "contrarian" climate science deniers -- those not being paid to deny it, at least. Eventually it's no longer about real science and those in the know just get frustrated and give up on even debating the cranks (as my friend the veteran journalist Mark Hertsgaard has called them) -- which said cranks of course call "conspiracy."

The climate scientists' medical analogy is one I and others have used before; If you or somebody you love was seriously ill, and nine out of ten, or 97 out of 100 doctors shared an opinion on what should be done, would you go with the tiny minority opinion? With AIDS denialists, some public health efforts were diverted and wasted due to their intransigence, and some people may have died. With climate cranks, the stakes are even bigger. The climate scientists' new letter is unlikely to resolve the debate, as the many comments on it already indicated. But it's good to see the responsible majority speak out in such a forceful manner.

Their letter is here:

Check With Climate Scientists for Views on Climate

Do you consult your dentist about your heart condition? In science, as in any area, reputations are based on knowledge and expertise in a field and on published, peer-reviewed work. If you need surgery, you want a highly experienced expert in the field who has done a large number of the proposed operations.

You published "No Need to Panic About Global Warming" (op-ed, Jan. 27) on climate change by the climate-science equivalent of dentists practicing cardiology. While accomplished in their own fields, most of these authors have no expertise in climate science. The few authors who have such expertise are known to have extreme views that are out of step with nearly every other climate expert. This happens in nearly every field of science. For example, there is a retrovirus expert who does not accept that HIV causes AIDS. And it is instructive to recall that a few scientists continued to state that smoking did not cause cancer, long after that was settled science.

Climate experts know that the long-term warming trend has not abated in the past decade. In fact, it was the warmest decade on record. Observations show unequivocally that our planet is getting hotter. And computer models have recently shown that during periods when there is a smaller increase of surface temperatures, warming is occurring elsewhere in the climate system, typically in the deep ocean. Such periods are a relatively common climate phenomenon, are consistent with our physical understanding of how the climate system works, and certainly do not invalidate our understanding of human-induced warming or the models used to simulate that warming.

Thus, climate experts also know what one of us, Kevin Trenberth, actually meant by the out-of-context, misrepresented quote used in the op-ed. Mr. Trenberth was lamenting the inadequacy of observing systems to fully monitor warming trends in the deep ocean and other aspects of the short-term variations that always occur, together with the long-term human-induced warming trend.

The National Academy of Sciences of the U.S. (set up by President Abraham Lincoln to advise on scientific issues), as well as major national academies of science around the world and every other authoritative body of scientists active in climate research have stated that the science is clear: The world is heating up and humans are primarily responsible. Impacts are already apparent and will increase. Reducing future impacts will require significant reductions in emissions of heat-trapping gases.

Research shows that more than 97% of scientists actively publishing in the field agree that climate change is real and human caused. It would be an act of recklessness for any political leader to disregard the weight of evidence and ignore the enormous risks that climate change clearly poses. In addition, there is very clear evidence that investing in the transition to a low-carbon economy will not only allow the world to avoid the worst risks of climate change, but could also drive decades of economic growth. Just what the doctor ordered.

Kevin Trenberth, Sc.D.

Distinguished Senior Scientist, Climate Analysis Section, National Center for Atmospheric Research

Richard Somerville, Ph.D., Distinguished Professor, Scripps Institution of Oceanography, University of California, San Diego

Katharine Hayhoe, Ph.D., Director, Climate Science Center, Texas Tech University

Rasmus Benestad, Ph.D., Senior Scientist, The Norwegian Meteorological Institute

Gerald Meehl, Ph.D., Senior Scientist, Climate and Global Dynamics Division, National Center for Atmospheric Research

Michael Oppenheimer, Ph.D., Professor of Geosciences; Director, Program in Science, Technology and Environmental Policy, Princeton University

Peter Gleick, Ph.D., co-founder and president, Pacific Institute for Studies in Development, Environment, and Security

Michael C. MacCracken, Ph.D., Chief Scientist, Climate Institute, Washington

Michael Mann, Ph.D., Director, Earth System Science Center, Pennsylvania State University

Steven Running, Ph.D., Professor, Director, Numerical Terradynamic Simulation Group, University of Montana

Robert Corell, Ph.D., Chair, Arctic Climate Impact Assessment; Principal, Global Environment Technology Foundation

Dennis Ojima, Ph.D., Professor, Senior Research Scientist, and Head of the Dept. of Interior's Climate Science Center at Colorado State University

Josh Willis, Ph.D., Climate Scientist, NASA's Jet Propulsion Laboratory

Matthew England, Ph.D., Professor, Joint Director of the Climate Change Research Centre, University of New South Wales, Australia

Ken Caldeira, Ph.D., Atmospheric Scientist, Dept. of Global Ecology, Carnegie Institution

Warren Washington, Ph.D., Senior Scientist, National Center for Atmospheric Research

Terry L. Root, Ph.D., Senior Fellow, Woods Institute for the Environment, Stanford University

David Karoly, Ph.D., ARC Federation Fellow and Professor, University of Melbourne, Australia

Jeffrey Kiehl, Ph.D., Senior Scientist, Climate and Global Dynamics Division, National Center for Atmospheric Research

Donald Wuebbles, Ph.D., Professor of Atmospheric Sciences, University of Illinois

Camille Parmesan, Ph.D., Professor of Biology, University of Texas; Professor of Global Change Biology, Marine Institute, University of Plymouth, UK

Simon Donner, Ph.D., Assistant Professor, Department of Geography, University of British Columbia, Canada

Barrett N. Rock, Ph.D., Professor, Complex Systems Research Center and Department of Natural Resources, University of New Hampshire

David Griggs, Ph.D., Professor and Director, Monash Sustainability Institute, Monash University, Australia

Roger N. Jones, Ph.D., Professor, Professorial Research Fellow, Centre for Strategic Economic Studies, Victoria University, Australia

William L. Chameides, Ph.D., Dean and Professor, School of the Environment, Duke University

Gary Yohe, Ph.D., Professor, Economics and Environmental Studies, Wesleyan University, CT

Robert Watson, Ph.D., Chief Scientific Advisor to the UK Department of Environment, Food and Rural Affairs; Chair of Environmental Sciences, University of East Anglia

Steven Sherwood, Ph.D., Director, Climate Change Research Centre, University of New South Wales, Sydney, Australia

Chris Rapley, Ph.D., Professor of Climate Science, University College London, UK

Joan Kleypas, Ph.D., Scientist, Climate and Global Dynamics Division, National Center for Atmospheric Research

James J. McCarthy, Ph.D., Professor of Biological Oceanography, Harvard University

Stefan Rahmstorf, Ph.D., Professor of Physics of the Oceans, Potsdam University, Germany

Julia Cole, Ph.D., Professor, Geosciences and Atmospheric Sciences, University of Arizona

William H. Schlesinger, Ph.D., President, Cary Institute of Ecosystem Studies

Jonathan Overpeck, Ph.D., Professor of Geosciences and Atmospheric Sciences, University of Arizona

Eric Rignot, Ph.D., Senior Research Scientist, NASA's Jet Propulsion Laboratory; Professor of Earth System Science, University of California, Irvine

Wolfgang Cramer, Professor of Global Ecology, Mediterranean Institute for Biodiversity and Ecology, CNRS, Aix-en-Provence, France