Consider another, even more schematic, "environmental problem"—Garrett Hardin's tragedy of the commons (1968). Hardin's parable, while introduced as applicable to human reproductive decisions and human population, is remarkable in its broad applicability to virtually every environmental problem. Hardin's parable achieves such generality because environmental quality is so often a public good that must be achieved in spite of individual interest, rather than because of it. No matter how large a finite commons, the unfettered exercise of individual, self-oriented values will lead eventually to its destruction; as the "herd" is expanded by individual choice, the individual-scale decisions will add up to a total effect too great for the carrying capacity of the commons. Individuals, motivated by short-term profits, will not adequately consider the longer-term consequences of their actions, because these are delayed and diffused throughout the community—they exist on another scale in time and space. Unless individual action is limited by mutually agreed-upon constraint, the public interest will be destroyed by individual choices. Hardin's scenario is our scenario, because we are at that point in history at which human population and industrial growth are approaching or surpassing the carrying capacities of many systems. In this unprecedented situation, even the functioning of ecosystems essential to regional economies and communities become public goods. They represent resources that cannot be owned—they are available to everyone if they are available to anyone—and they can be destroyed by aggregate action in which each individual actor seeks his or her self-interest exclusively. Hardin's parable, by modeling environmental problems as community-scale problems resulting from individually motivated decisions, therefore illustrates in general terms how environmental problems are most basically problems of scale.
Recent groundbreaking work by Holling has hypothesized, and provided significant empirical evidence, that the dynamics of natural systems "are controlled and organized by a small set of key plant, animal, and abiotic processes." He further argues that "the geometry of landscapes and ecosystems is organized into a small number of quanta with distinct architectural attributes," attributes that are especially relevant from a human perspective (Holling, 1992, p. 449; also see Allen and Starr, 1982; Norton and Ulanowicz, 1992; O'Neill et al., 1986).
Holling's work supports, both theoretically and empirically, a broadly hierarchical approach to understanding physical and ecological processes, suggesting that the human tendency to understand complex systems hierarchically (noted by Allen and Hoekstra, 1992; Allen and Starr, 1982) is not adventitious. It is a structural aspect of natural systems as they are experienced by human observers. Indeed, Holling's evidence suggests that all mammals of roughly human body size must perceive the world as organized according to similar scalar properties. Holling concludes that "The landscape is structured hierarchically by a small