Many critics of Bj¿rn Lomborg's book refer to Mark Twain's comment about "lies, damn lies and statistics," but I am more reminded of H. L. Mencken's remark, "For every problem, there is a neat, simple solution, and it is always wrong." The story of The Skeptical Environmentalist is one of a political scientist who wades into the vastly complex, unsettled literature of environmental science, scrutinizes a fraction of what is to be found there, and emerges confident that the simple summary he has developed is a fair and accurate representation of the science¿notwithstanding the warnings of experts in the disciplines he skims that he is mistaken.
Lomborg has not taken these criticisms lying down, however, as his detailed rebuttal to our feature in Scientific American attests. Because of demands on their own time, most of the authors of our "Misleading Math about the Earth" section were unfortunately not available to write full responses to Lomborg's reply themselves. However, I have taken it upon myself to answer many of his counter-arguments, which display the same patterns of misdirection, bias and selective citation that our authors found in his book. (The responsibility for what appears here is entirely mine, but I do appreciate the contributions that our authors were able to offer in some sections, as noted.)
CONCERNING LOMBORG'S REPLY TO MY INTRODUCTION
Lomborg's criticisms begin with the subtitle for our article, "Science defends itself against The Skeptical Environmentalist." As he insists, his book "makes a claim to science and to be factually based," and therefore it is inappropriate to describe his work as an attack on science.
Yet Lomborg does emphatically deride the conclusions, judgment and integrity of researchers and organizations whose work represents the mainstream of environmental science (a few examples are described below, and the book contains many others). As for the status of Lomborg's book: Many people claim to have scientific arguments when they do not: creationists, ancient astronaut theorists and the like. Being able to cite the scientific literature does not automatically confer validity on one's argument, nor does it make the argument genuinely scientific.
This is why Lomborg is wrong in his rebuttal when he writes, "The discussion is whether the statements in my book are correct or not." The discussion is not about whether his statements are correct; it is about whether his arguments are correct¿the plans of thought he develops from those statements. Selective citations of the literature allow Lomborg to make statements that are correct but unrepresentative of the best, full state of environmental scientific knowledge. If Lomborg's book is science, then it should be judged by the criteria for other scientific publications. As many scientists have commented, his discussions would be unlikely to pass peer review because of his apparent unfamiliarity with prior literature, his selective citation of relevant work, and other faults.
The discussion is not about whether his statements are correct; it is about whether his arguments are correct¿the plans of thought he develops from those statements.
Lomborg takes exception to my chastising him for "literally not seeing the forests for the trees." He writes that "the longest data series actually tells us of very little change in the world forested area," but this is misleading. My comment springs from the fact that the data series may describe little change in the forested area, but the actual forests are subject to considerable clearing and replanting. Lomborg thus treats forests of new trees as ecologically equivalent to old-growth forests, which is clearly not true.
But even on its own terms, Lomborg's statement about forest cover does not hold up well. He is relying principally on data from the U.N.'s Food and Agriculture Organization (FAO). As Emily Matthews of the World Resources Institute has pointed out, the FAO compiled that data for agricultural purposes, and eventually stopped doing so because it felt that the data were inadequate for assessing forests accurately. Lomborg also quotes FAO figures for tropical deforestation as a percentage of total global forest cover, which greatly understating the pressure on tropical forests, where most of the deforestation is taking place.