There are at least two variants of the argument that biodiversity should be increased. The weak goal seeks only to weigh costs against benefits when choosing the level of protection to be given to endangered species. The strong goal requires that every endangered species be protected, regardless of expense.
Many environmentalists implicitly or explicitly espouse the strong goal, and it is this goal that is embodied in the Endangered Species Act (ESA). What I wish to argue here is, first, that the public has not supported this view. To the extent that they have accepted that increasing biodiversity is a desirable goal, it is the weak goal that they have adopted, not the strong goal. Second, I argue that environmentalists’ support for the strong goal is only the public expression of a deeper goal: the protection of natural landscapes.
First, it is clear that the public is not interested in the protection of all endangered species. It is much more interested in mammals and birds than in amphibians, invertebrates, and plants. Metrick and Weitzman (Journal of Economic Perspectives, 1998), for example, found that species were more likely to be listed as endangered under the ESA, and more money was likely to be spent on them, if they were mammals or birds than if they were fish, reptiles, or amphibians. And, as Peter Huber notes, in Hard Green, it is difficult to believe that the public’s desire to protect endangered species extends to species such as tapeworms and viruses that are positively harmful to human beings.
Second, if we assume that public policy reflects public preferences, there is considerable evidence that the public’s goal is something other than the protection of “endangered” species. The strongest evidence of this assertion comes from the listing of endangered species under the ESA. Of the 527 species of animals currently listed as endangered or threatened, only 51 percent are listed as endangered or vulnerable by the World Conservation Union (IUCN). And, of the 407 animal species that the IUCN considers to be endangered in the United States, only 180, 44 percent, are listed as being endangered or threatened.
Third, although the argument that cost is of no consideration may be defensible when considering the protection of individual species, (see the billions of dollars that have been spent on spotted owls and Florida panthers), when that argument is extended to all threatened species, it becomes much less tenable. It is not just that the public has less sympathy for some species than others, as Metrick and Weitzman found. It is that the number of known endangered and threatened species is so great that it is not plausible to argue that the public would be willing to spend unlimited funds to protect all of them.
According to the IUCN, for example, the United States has 5,568 threatened species (4,615 plants and 953 animals), Australia has 2,699, and Panama has 1,354. If protection of each species was to cost $1 billion, (an amount that is less than has been spent on spotted owls and Florida panthers), the United States would have to spend $5.6 trillion, Australia $2.7 trillion, and Panama $1.3 trillion to protect their known endangered species. Even if the true costs were one tenth of these, it is difficult to believe that this level of expenditure would be supported by most of the citizens of these countries.
In, short, the public does not appear to support the strong biodiversity goal – although there may be considerable support for some version of the weak goal. Rather, I suggest that there are many circumstances in which the argument for biodiversity masks a different, but related, goal: the preservation of landscapes in their natural state.
Dozens, if not hundreds, of examples can found of situations in which environmental groups had pressed unsuccessfully for preservation of a habitat, not because it was believed that the habitat was home to an endangered species, but because the proponents wished to preserve the natural landscape. When an endangered species was found to live in the habitat, the presence of that species was used to justify the preservation of the species’ habitat. For example, opponents of suburban growth have discovered new allies in the pygmy owl on the outskirts of Tucson; the golden-cheeked warbler in the Balcones Canyonland on the edge of Austin; Preble’s meadow jumping mouse habitat near Denver; and Orcutt grass and fairy shrimp in Sacramento. And the spotted owl has provided a trump card for those who had previously fought unsuccessfully for preservation of old growth forests in Washington and Oregon.
In none of these cases can the sincerity of the proponents of endangered species protection be questioned. But in each case, and in many others, it is clear that preservation of natural landscapes was of at least as much importance as preservation of species. My argument here is that, in the public debate, it is important to recognise what the true, underlying goal of public policy is. In this case, I suggest that we would be advised to place less emphasis on species and more on landscapes.
