UCS Examines 'The Skeptical Environmentalist'

A book by Bjørn Lomborg, a political scientist and professor of statistics at the University of Aarhus in Denmark, has created quite a stir since its 2001 release. Lomborg accuses scientists and environmental organizations of making false and exaggerated claims about the world's environmental problems. He concludes that population growth is not a problem, that there is plenty of freshwater around, that deforestation rates and species extinctions are grossly exaggerated, that the pollution battle has been won, and that global warming is too expensive to fix. A self-proclaimed environmentalist and skeptic, he claims that his reanalysis of environmental data measures "the real state of the world."

The heavily promoted book, published by Cambridge University Press, has received significant attention from the media and praise from commentators writing in The Economist, The New York Times, and Washington Post. For example, the Post's reviewer (a philosophy professor from New Zealand) concluded that it was "a magnificent achievement," and "the most significant work on the environment since the appearance of its polar opposite, Rachel Carson's Silent Spring, in 1962."

Meanwhile, groups with a vested interest in maintaining the status quo are using the book to promote their "no need to take action to address global environmental problems" agenda. For example, the "Cooler Heads Coalition" -- formed by the Competitive Enterprise Institute and others to "dispel the myths of global warming" -- featured Lomborg in a Capitol Hill briefing on global warming.

Does this book merit such positive attention? Does Lomborg provide new insights? Are his claims supported by the data? A healthy skepticism towards the claims of others is, after all, one of the hallmarks of good science. And, at first glance, Lomborg's book appears to be an objective and rigorous scientific analysis. It is published by a leading academic press, and contains an extensive bibliography and nearly 3,000 footnotes.

To answer these questions, UCS invited several of the world's leading experts on water resources, biodiversity, and climate change to carefully review the sections in Lomborg's book that address their areas of expertise. We asked them to evaluate whether Lomborg's skepticism is coupled with the other hallmarks of good science – namely, objectivity, understanding of the underlying concepts, appropriate statistical methods and careful peer review.

Reviewing Lomborg's claims are Dr. Peter Gleick, an internationally recognized expert on the state of freshwater resources; Dr. Jerry Mahlman, one of the most highly regarded atmospheric scientists and climate modelers; and top biologists and biodiversity experts Dr.'s Edward O. Wilson, Thomas Lovejoy, Norman Myers, Jeffrey Harvey and Stuart Pimm.

These separately written expert reviews unequivocally demonstrate that on closer inspection, Lomborg's book is seriously flawed and fails to meet basic standards of credible scientific analysis. The authors note how Lomborg consistently misuses, misrepresents or misinterprets data to greatly underestimate rates of species extinction, ignore evidence that billions of people lack access to clean water and sanitation, and minimize the extent and impacts of global warming due to the burning of fossil fuels and other human-caused emissions of heat-trapping gases. Time and again, these experts find that Lomborg's assertions and analyses are marred by flawed logic, inappropriate use of statistics and hidden value judgments. He uncritically and selectively cites literature -- often not peer-reviewed -- that supports his assertions, while ignoring or misinterpreting scientific evidence that does not. His consistently flawed use of scientific data is, in Peter Gleick's words "unexpected and disturbing in a statistician".

These reviews show that The Skeptical Environmentalist fits squarely in a tradition of contrarian works on the environment that may gain temporary prominence but ultimately fail to stand up to scientific scrutiny. Others, such as Julian Simon and Gregg Easterbrook, have come before him, and others no doubt will follow. Correcting the misperceptions these works foster is an essential task, for, as noted above, groups with anti-environmental agendas use these works to promote their objectives. It is also an unfortunate, time-consuming distraction, for it pulls talented scientists away from the pressing research needed to help us understand the environmental challenges we face and their prospective solutions.

Winston Churchill once said, "A lie gets halfway around the world before the truth has a chance to get its pants on", reminding usof the parable of the Tortoise and the Hare. Like the Hare, Lomborg's lie has raced out in front of the truth. With the help of these careful scientific peer reviews, UCS hopes that the truth, like the Tortoise, will catch up and emerge the ultimate victor.

Editor's note: In addition to these UCS-solicited reviews, critiques of Lomborg's book have also been published in Scientific American, Nature, Science, and other scientific journals, as well as on several web sites.