more energy per unit of gross national product than most other Western industrialized countries? Why are ancient forests destroyed more rapidly in some societal settings than in others? How can we account for large discrepancies in land use practices, even among societies that resemble each other in many ways? These are complex questions that social science cannot answer now with confidence. Nonetheless, such questions can be analyzed with social science techniques, and a serious literature relating to many questions of this sort is available for study.
For example, researchers who examine the different patterns of energy consumption in the United States and Canada on the one hand and Western Europe and Japan on the other have much to say about the relative importance of geography (for example, distances between human settlements), demography (for example, the dispersal of human populations into suburbs), economics (for example, the relative costs of labor and energy as factors of production), infrastructure (for example, the prevalence of central heating in homes), and public policy (for example, taxes, subsidies, and policies governing rents from natural resources) as determinants of the propensity of North Americans to rely more heavily on energy as a factor of production than Europeans or especially the Japanese do (e.g., Schipper et al., 1985; Schipper, 1989). Similarly, researchers who examine the pace of deforestation and the spread of large-scale cattle ranching in the Amazon Basin are engaged in a lively debate about the relative importance of institutional factors (for example, systems of land tenure), technological factors (for example, the introduction of modern road building and land clearing equipment), international economic factors (for example, the growth of a world market for lean beef), political factors (for example, various forms of tax relief and public subsidies for activities involving land clearing), cultural factors (for example, the tendency to apply a frontier mentality to decisions about the Amazon), and population growth as determinants of the destruction of Amazonian moist forests (e.g., Hecht, 1985; World Resources Institute, 1985). The techniques exist to greatly improve understanding of how such factors act separately and together to influence the proximate human causes of global change.
The social sciences can also contribute by using available conceptual and theoretical constructs to illuminate problems of global change. For example, one of the most powerful and well-documented findings in social science is that apparently rational actors engaged in interactive decision making can and often do end up with outcomes that are less than optimal—and in some