A Review of The Skeptical Environmentalist: Measuring the Real State of the World by Bjørn Lomborg

[1] The Skeptical Environmentalist (by Bjørn Lomborg) is a copiously-referenced (2930 citations!) assessment of global environmental health by a professor at a Danish university trained as a political scientist and statistician. Lomborg’s principal thesis is that the vast majority of environmental problems are either overstated or non-existent. Lomborg refers to tendency to exaggerate as “The Litany”- a gloom-and-doom perception of the state of our environment derived from flawed interpretations of data or even a deliberate misrepresentation of the facts by some in the environmental movement.

[2] As a college student in the late seventies, I received what Lomborg would probably call an indoctrination in “The Litany.” I vividly and fondly recall classes in which we ardently discussed Limits to Growth (a text [Meadows et al. 1972] that served as an apologetic for the environmental movement of the seventies and eighties and is oft-criticized in The Skeptical Environmentalist) and I remain an admirer of Amory Lovins’ ideas about renewable energy resources. As such, one would expect that I would reject, in toto, Lomborg’s revisionist notions about the state of our environment. Yes and no. As a scientist (I have a Ph.D in Plant Biology), I am alarmed by the lack of scientific rigor in the debate about the state of the environment. Far-ranging claims about the health of our environment often appear to be based on limited lines of evidence. Thus, I find myself in sympathy with at least one of the basic sentiments expressed in The Skeptical Environmentalist – one should not blindly accept all that is espoused by the environmental movement. Moreover, the data on which Lomborg bases his conclusions in The Skeptical Environmentalist are cited and documented. As a consequence, readers can examine the raw data and then evaluate Lomborg’s conclusions. Lomborg is to be commended for approaching the issue with a transparency that at least attempts to introduce scientific rigor.

[3] But, is The Skeptical Environmentalist good science? In my opinion, the answer is “no” because The Skeptical Environmentalist fails one of the requirements for scientific scholarship – peer review. All good scholarship in science goes through a process in which numerous experts in the field review the material as an unpublished manuscript. The Skeptical Environmentalist has not been subjected to peer review; which was not an oversight on the part of Lomborg, but the path he chose for publication of the material. Why are the scientific merits of the book a relevant issue, if Lomborg had no intention of publishing his manuscript in the tradition of scientific scholarship? At least some are touting the book as a scientific challenge to the environmental movement. Yes, Lomborg has assembled and interpreted an impressive array of published data for which he deserves credit. However, the fact remains that the book represents his interpretations of the evidence.

[4] One might ask a follow-up question: “Why can’t you, a scientist, evaluate the merits of Lomborg’s thesis?” The answer is that I don’t have the expertise in the broad spectrum of topics covered by The Skeptical Environmentalist. In fact, I would be surprised if any single individual could have a depth of expertise in all of the subjects addressed in The Skeptical Environmentalist. It is this observation that leaves me uneasy about the conclusions in Lomborg’s book. A survey of the myriad post-publication reviews suggests that Lomborg generally supports a minority viewpoint in his book. Rightly or wrongly, this situation reminds me (as a plant evolutionary biologist) of exchanges I have had with creationists who use their interpretation of evidence on topics ranging from astrophysics to zoology to challenge evolutionary theory. I am occasionally unable to answer immediately some of these challenges simply because the subject (e.g., astrophysics) lies outside my area of expertise. However, a quick trip to the library or a conversation with a learned colleague has always provided me with an answer to the creationist challenge. Moreover, these exchanges generally reveal the challenger to be unfamiliar with the full spectrum of issues regarding a given subject. Is it possible that Lomborg, who is not an expert in most of the topics he covers, has missed key points of the environmental debate? Many of Lomborg’s critics make just this claim. A more cynical question would be “Has Lomborg interpreted the data he cites in order to fit them into a pre-conceived outcome?”

[5] Finally we consider the ethical questions brought to the fore by The Skeptical Environmentalist: “Has Lomborg factored ethics into his interpretations of the evidence?” Although Lomborg pays lip service to ethical considerations, it is clear that the bottom line is the bottom line – would the benefits derived from an environmental remediation activity justify the cost? For example, Lomborg addresses the question of biodiversity and concludes that the background rates of extinction currently accepted by the majority of biologists are grossly exaggerated and that, therefore, the need to preserve biological diversity is likewise exaggerated. Furthermore, Lomborg essentially concludes that efforts to conserve some species (e.g., many invertebrates and most microbes) to be of little economic benefit since these organisms do not factor into an aesthetic need (i.e., most of us would not mourn the extinction of the green alga Pediastrum, but many would care deeply if the beloved African Elephant disappeared) nor are these organisms likely to offer any economic incentives for preservation (i.e., they don’t produce any economically important byproducts). Interestingly, this topic allows us to examine the limits of scientific evidence in the grand debate. A wealth of data regarding changes over time in the diversity of organisms can be assembled with relative ease. However, the inherent uncertainty associated with these data can allow for varied interpretations regarding, for example, the background extinction rate. More importantly, one cannot test hypotheses about the economic or ecological effects of a given extinction event, since one cannot perform the control treatments of such an experiment. In my opinion, this observation can be extended to other areas of the environmental debate. If science is not definitive, how are we to proceed in the environmental debate? It is clear to me that this debate represents a complex interplay of ethical considerations and empirical evidence. My concern is that the Lomborg ethos has “maximize profits” as the prime directive and that this is coloring the interpretations of the data. Could it not be argued that a more biblical, stewardship approach to managing the environment is a legitimate alternative ethos? What is the appropriate ethical framework in which to evaluate the data generated in the debate on the environment? This question is not addressed in The Skeptical Environmentalist.

[6] It is clear that the skepticism of the environmental movement advocated by Lomborg is a double-edged sword – the same skepticism needs to be applied to The Skeptical Environmentalist. We need to acknowledge that an honest evaluation of empirical evidence is essential in defining the parameters of the debate, but that ethical yardsticks will also be part of the equation and may even color our interpretations. Should you read this book? Sure (especially if you have a stake in the environmental debate). Does this book represent a serious challenge to environmental dogma? The jury is still out.


Meadows, D. H., Meadows, D. L., Randers, J. & Behrens III, W. W. 1972. Limits to Growth. London, Potomac Associates Book