to take it. Besides, the reasoning goes, there is no "scientific proof" of any failure in ecosystem services, and most predictions of the consequences of loss of biodiversity, global warming, ozone holes in the atmosphere, and the like seem much less threatening than job loss, reduction in gross national product, or loss of present amenities resulting from high per capita energy consumption and lowered product costs because environmental externalities are not included in economic analyses. Substantial literature exists on social traps, but some illustrative materials are Brockner and Rubin (1985), Cross and Guyer (1980), Platt (1973), Teger (1980), and, particularly relevant to this discussion, Costanza (1987, and in this volume) and Geller (1994).

Balancing Technological And Natural Services

In developing a guiding model for achieving a balance between technological and ecosystem services, it is helpful to see what humans did when the technology was primitive and human populations comparatively small. At least some preindustrial tribes revered their local environment, but Diamond (1992, 1994) has suggested that the relationships between primitive peoples and their natural environments were not always sustainable. Probably the best known, much earlier exponent of this outlook was Rousseau (1754), whose discourse on the origin of inequality traced humanity's degeneration from the golden age to the misery that now exists in all too much of the world.

Where peoples living in harmony with nature persist, they have been driven to areas that no one else wants. This is true of the Bushmen in the Kalahari Desert and some of the few remaining indigenous societies in the Amazon basin and parts of Australia. Since the agricultural revolution some 10,000 years ago, the agrarians have always outnumbered the hunters and gatherers and, even if they were less skillful in warfare, could overwhelm them by sheer numbers. Some of the literature that is particularly interesting in this regard is Hughes (1975), Kirch (1984), Martin (1973), Martin and Klein (1984), Mosimann and Martin (1975), Samuels and Betancourt (1982), and Yoffee and Cowgill (1988). Despite uncertainties and controversy about the literature from which these selections are taken, it is clear that even the primitive technologies of human society when used with teamwork and intelligence could cause considerable environmental havoc.

Ornstein and Ehrlich (1989) speculate that there could be no selective pressures likely to result in a genetic trait prohibiting excessive depletion of resources or conditioning an individual toward long-term sustainable use of a resource base. The rewards for exploitative behaviors are too immediate; the consequences too delayed. Even if the level of technology used by the hunters and gatherers was acceptable to human society (which is no longer the case), population densities alone preclude using such a model, at least for many generations. Of course, many species are left, so, as Diamond notes, the golden age may not have been as golden as it was thought to be, but neither was it all black. Human



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