The Climate-Change Nay-Sayers are Wrong
George M. Woodwell and John P. Holdren
No environmental issue has received more intensive scrutiny by the scientific community than the disruption of global climate now underway as the result of human additions of "green- house" (heat-trapping) gases to the atmosphere. This topic has been reviewed systematically and repeatedly by a large international scientific body constituted by the world's governments for this purpose (the Intergovernmental Panel on Climate Change -- IPCC), as well as by scientific academies around the world and countless national and international scientific symposia.
The conclusions of these many reviews by the scientists most qualified to address the issue have been strikingly consistent in recognizing the reality and the seriousness of the greenhouse-gas-induced global warming. This agreement rests on direct measurements of land and ocean temperatures going back a century and a half; on indirect evidence from tree rings and ice cores extending back for millennia; on measurements of precipitation, snow cover, sea level, the extent of sea ice, and other environmental phenomena that depend on the Earth's temperature; and on analyses and computer simulations showing that the observed changes are the ones to be expected from the changes in atmospheric composition that human activities have caused.
The consistency and clarity of the warnings emanating from the traditionally cautious worldwide scientific community led in 1992 to the Framework Convention on Climate Change, calling for steps to reduce the risks posed to human well-being by rising emissions of greenhouse gases. That Convention -- in which the parties agree to develop, publish, and implement plans to reduce their greenhouse-gas emissions -- was promptly ratified by the United States and more than 165 other countries.
The scientific evidence about the climate-change danger has only become stronger since, but so has the backlash from a handful of dissenting scientists backed by certain fossil-fuel producers' and users' groups, conservative think tanks, and other interests committed to "business as usual" no matter what the risks. These "climate skeptics" have made a cottage industry out of puffing up the uncertainties in climate science (which are real, but do not touch the core conclusion that rising greenhouse-gas concentrations pose serious dangers for human well- being) and out of recycling long-discredited objections to the mainstream consensus on the issue.
The skeptics' disinformation has found a ready audience among glib conservative columnists -- who lack the capacity to evaluate these arguments but not the confidence to make ringing declarations about who is right -- as has recently been illustrated yet again by Jeff Jacoby's column in the Boston Globe of November 5.
Jacoby asserts that "it is important to explode the myth that most scientists are worried about global warming" and purports to do so by referring to a pair of thoroughly discredited petitions claiming that there is no scientific consensus on the climate danger. The first of these, the "Global Warming Petition" circulated over the name of Dr. Frederick Seitz, is said by Jacoby to have gained the signatures of "nearly 17,000 US scientists". This petition has long since been recognized in the serious scientific community as a farce. The signatories are listed in the Petition without title, affiliation, area of expertise, or any other means to check the signers' credentials as scientists or even their existence. Indeed, among the names offered can be found the author John Grisham, several doctors from the TV series "MASH", and a Spice Girl.
The "eight-page abstract of the latest research on climate change", which accompanied the Seitz petition and which Jacoby praised as "written for scientists but comprehensible by laymen" is in fact a tissue of mistakes and distortions written by a father-and-son team lacking any qualifications in climate science whatever. The piece did achieve a degree of plausibility with the gullible by being formatted to mimic an article from The Proceedings of the National Academy of Sciences and accompanied by a letter from a long-retired president of that Academy (Dr. Seitz, who, specialists would know, has no expertise in climate matters). The National Academy of Sciences felt compelled to disassociate itself publicly from this communication, stating that it"does not reflect the conclusions of expert reports of the Academy".
The second petition cited by Jacoby, the "Leipzig Declaration", is the work of S. Fred Singer, a well known climate skeptic who was also loudly wrong about the stratospheric ozone problem. Jacoby claims that Singer's Declaration was signed by more than 100 climate scientists; but, as with the Seitz petition, the credibility of the Singer effort dissolves under scrutiny. The list contains 80 signatures. Danish television recently surveyed them all and found an odd assortment of television weather-persons, dentists, lab assistants, civil engineers, and even people who, despite their names' appearing on the list, swear they never heard of the Declaration.
It is both pathetic and troubling that climate-change skeptics continue to try to use these discredited petitions to attack the mainstream scientific consensus on the global-warming danger. Even more troubling is that there are so many columnists like Jacoby who are eager to propagate this nonsense without a glimmer of understanding of the subject. It must be hoped that such disinformation will not contribute to delaying further the process, now underway in Buenos Aires, of seeking cooperative and cost-effective international approaches to reducing the dangers that greenhouse-gas-induced climate change poses to Jacoby's children and grandchildren as well as to our own.
Dr. Woodwell is the Director of the Woods Hole Research Center. Dr. Holdren is a professor in the Kennedy School of Government and the Department of Earth and Planetary Sciences at Harvard University, and a member of President Clinton's Committee of Advisors on Science and Technology. Both are members of the National Academy of Sciences.