Dissident from Denmark.

The Skeptical Environmentalist: Measuring the Real State of the World, by Bjorn Lomborg (Cambridge, 515 pp., $28)

Bjorn Lomborg is the environmentalists' Enemy Number One. He isn't the CEO of a major oil company or an industry lobbyist; he doesn't lambaste "environmental wackos" on talk radio, nor, so far as we can tell, did he provide secret briefings to Vice President Cheney. Lomborg is an associate professor of statistics in the political-science department at the University of Aarhus in Denmark, and all he did was write this book-which represents the most substantial challenge to the green orthodoxy that modern civilization is producing environmental ruin. On the basis of a mountain of statistical data-documented in over 500 pages, with almost 3,000 footnotes-Lomborg proclaims that "things are getting better," and that there is no reason that the good news can't continue.

Lomborg did not intend to report the good news about Planet Earth. He began his project as an attempt to debunk the late enviro-optimist Julian Simon, who infuriated modern-day Malthusians with his rosy assessments of global trends. In 1997, Lomborg happened across an interview with Simon in Wired magazine. Confronted with Simon's positive assessment of the planet's condition, he sought to prove that such views were the product of "American right-wing propaganda." He gathered ten of his best students and set about checking the data behind Simon's claims. "Contrary to our expectations," Lomborg reports in the preface, "it turned out that a surprisingly large amount of his points stood up to scrutiny." The doomsday visions offered up by most mainstream environmental groups did not. Lomborg expanded his research on environmental problems, eventually producing The Skeptical Environmentalist.

The focus of this book is "the Litany of our ever deteriorating environment" proclaimed by environmental activist groups and echoed throughout the media and popular culture. You've heard "the Litany" before: Resources are running out, population growth is outpacing food supplies, species and their habitats are disappearing, and pollution keeps getting worse. In sum, humanity is despoiling the planet and threatening human civilization in the process. "We know the Litany and have heard it so often that yet another repetition is, well, almost reassuring," Lomborg explains. "There is just one problem: It does not seem to be backed up by the available evidence."

What follows is an encyclopedic assessment of environmental concerns, from population growth and food supplies to energy and global warming. On each subject, Lomborg compares the conventional environmental assessment with the publicly available data. Time and again, the most apocalyptic environmental claims come up short-far short. "Mankind's lot has actually improved in terms of practically every measurable indicator," he explains. People are living longer, healthier lives than ever before. Food production continues to keep pace with population, while health threats are diminishing, along with most forms of pollution. Stresses on some natural resources are very real, Lomborg notes, as in the case of some fisheries and tropical forests, but the problems are not as severe as often depicted.

Even if professional doomsayers concede that things are getting better, they continue to charge that we are living on borrowed time: If population growth or chemical pollution will not do us in, then global warming will. Lomborg takes this charge seriously-he believes that human activity is measurably warming the earth-but he rejects the notion of a greenhouse apocalypse. Any temperature increase is likely to be modest, not catastrophic. While the costs of such a warming are real, "economic analyses clearly show that it will be far more expensive to cut [greenhouse gas] emissions radically than to pay the costs of adaptation to the increased temperatures." The Kyoto Protocol signed by the Clinton administration and championed by environmentalists is a bad deal. In the end, global warming is "a limited and manageable problem."

In many quarters, Lomborg's book has been greeted with horror and fury. Activist groups and environmental analysts have begun anti-Lomborg websites, published various critiques, and launched vicious ad hominem attacks. One "green" reviewer warns that Lomborg is a "junior" statistics professor and not an environmental expert-as if that would change the underlying data Lomborg cites. Jonathan Lash, president of the World Resources Institute, wrote a letter to environmental journalists warning that the book is misleading and has been "heavily publicized and championed by conservatives." Another "researcher," less prone to reasoned discourse, assaulted Lomborg with a pie.

Perhaps the most notable attack so far has appeared in Scientific American. Under the headline "Science Defends Itself Against The Skeptical Environmentalist," the popular science magazine published four essays by activist researchers, including two whom Lomborg criticizes by name. As with most of the attacks, however, the essays decried Lomborg's theses without identifying significant substantive errors. Stanford's Stephen Schneider, for example, claimed Lomborg was selective in his presentation of economic studies on global warming, but in fact it was Schneider who misconstrued (or misrepresented) Lomborg's claims.

John Holdren of Harvard University's Kennedy School complained that Lomborg focused on neo-Malthusian fears that we are running out of energy. Serious environmentalists, Holdren counseled, have long abandoned such concerns. That may have come as a surprise to Scientific American's readers, however, as the monthly has recently published several articles and reviews suggesting that depletion of oil supplies could be imminent. Challenged on this point, Scientific American editor-in-chief John Rennie replied that his magazine's articles were about the end of "cheap oil," not the exhaustion of physical supplies. Not only is this a distinction without a difference-as oil supplies dwindle, prices rise-but Lomborg makes clear throughout his energy chapter that his target is the argument that we will run out of affordable energy. As he explains, "Even if we were to run out of oil, this would not mean that oil was unavailable, only that it would be very, very expensive. If we want to examine whether oil is getting more and more scarce we have to look at whether oil is getting more and more expensive." Lomborg then proceeds to show that oil has been getting cheaper as available supplies increase. Should this trend reverse, price signals will encourage the development of other energy sources.

While Lomborg is an optimist, he is no Pollyanna. He regularly pauses to remind the reader that environmental concerns are real. The claim that 40,000 species disappear every year may have no empirical basis whatsoever, but Lomborg leaves no doubt that extinction rates are on the rise and that human activity is largely to blame. This, he says, is a "problem," not a "catastrophe." The record of environmental progress is impressive, particularly in the developed world, but substantial environmental concerns remain in the poorer nations of the developing world-for example, suffocating air pollution and inadequate supplies of drinking water. Continued economic growth may one day alleviate these concerns, but millions suffer from severe pollution today. Lomborg's frank and repeated acknowledgements of the need for environmental progress are hard to square with the caricature presented by his critics.

Fears of an environmental cataclysm have driven the growth of governmental power at the local, national, and even international levels; hundreds of pages in the U.S. Code are devoted to environmental concerns, as are dozens of international treaties. A great portion of these measures seek to address the very problems Lomborg identifies as overstated. Yet other than the Kyoto Protocol, Lomborg critiques surprisingly few environmental initiatives. Beyond increases in foreign aid and generic policies that promote economic growth, his most substantial policy recommendation is to rely on quantitative analysis to set environmental priorities.

It's true that science-based risk prioritization is often lacking in environmental policy, but it is insufficient as a policy agenda: "Sound science" is only one piece of the puzzle. The accumulation of statistics on environmental trends provides a useful snapshot of the global condition, but it does not answer pressing questions, such as how to address uncertainty in environmental risk, or what obligations (if any) humanity has to future generations or to the rest of nature. Once priorities are set, substantial questions remain about how to achieve environmental goals.

While environmental progress is indeed the norm today, it is not universal: Positive global trends often mask local or regional regression. Buried in the data is a pattern illustrating the nature of environmental problems-and their resolution: Wealthier societies are healthier societies, and are more willing to devote resources to environmental concerns. But this is only part of the picture. Equivalent wealth increases have not always produced equivalent environmental results. Legal and economic institutions play an essential role in facilitating environmental protection. In his brief discussions of forests and fish, Lomborg hints at the role that property rights play in the stewardship of natural resources, but this awaits a fuller discussion.

The conventional wisdom holds that modern environmental regulation must take most of the credit for positive environmental trends. Yet Lomborg suggests that the role of regulation is overstated. Key turning points in environmental trends often predated federal environmental legislation. In the states, airborne-particulate concentrations peaked in the 1950s, more than a decade before creation of the Environmental Protection Agency. Smoke and sulfur-dioxide levels peaked in London nearly a century ago. Here again, however, Lomborg is reluctant to give the data much interpretation.

Despite these minor flaws, his compilation of environmental data remains invaluable. The Skeptical Environmentalist provides no brief for environmental complacency, but it provides plenty of reasons to feel good about the earth-which is in far better shape than green activists would have us believe. The truth matters: Lomborg's claims are supported by an arsenal of hard data, and are easy to confirm. And that, in the final analysis, is what has his critics so upset.