We are in the midst of a transition to a world in which human populations are more crowded, more consuming, more connected, and in many parts of the world, more diverse, than at any time in history. Current projections envisage population reaching around 9 billion people in 2050 and leveling off at 10 to 11 billion by the end of the next centuryclose to double that of today's 6 billion.1 Most of this future growth will be concentrated in the developing countries of Africa, Asia, and Latin America, where the need to reduce poverty without harm to the environment will be particularly acute. Meeting even the most basic needs of a stabilized population at least half again as large as today's implies greater production and consumption of goods and services, increased demand for land, energy, and materials, and intensified pressures on the environment and living resources. These challenges will be compounded to the extent that the resource-intensive, consumptive lifestyles currently enjoyed by many in the industrialized nations are retained by them and attained by the rest of humanity.
Can the transition to a stable human population also be a transition to sustainability, in which the people living on earth over the next half-century meet their needs while nurturing and restoring the planet's life support systems? The toll of human development over the last half-century on the environment suggests that the answer may well be "no." The examples of Appalachian coal country, the Aral Sea, or the Southeast Asian forest fires serve as vivid reminders of how devastating to both society and the environment the implications of heedless development
can be. On a more optimistic note, people have begun learning how to secure more social "goods" while creating fewer environmental "bads" in activities ranging from agriculture to manufacturing to recreation. A remarkable number of efforts have grown up around the world over the last decade that have succeeded in putting sustainability issues on the global political agendaand in beginning the actual search for specific pathways toward sustainability in many local contexts. If, at the close of the 20th century, the end of our common voyage toward sustainability has not yet been charted, much less brought into sight, the journey has at least begun.
In recent years, the science and technology community has not been a particularly prominent participant on this journey. This has not always been the case. Early thinking on sustainability issuesfor example, the World Conservation Strategy2was firmly grounded in a scientific understanding of the workings and limits of resources and environmental systems. But, with the possible exception of the ozone protocols, the central thrusts of many recent sustainability initiatives have been shaped more by political than scientific ideas. Major recent innovations have come in the realm of policies and institutions, rather than knowledge and know-how. Relatively little progress has been made in developing a scientific understanding of the obstacles facing any transition to sustainability, the technological opportunities for pursuing this goal, or the use of modern sensing and information systems for providing navigational aids along the way.
The principal national and international reports have thus tended to address science and technology as necessary, potentially expensive, but otherwise unproblematic inputs to the process of sustainable development. As inputs, science and technology have been addressed either as highly specific requirements (e.g., methods for the safe disposal of nuclear wastes) or as the most general needs (e.g., enhanced scientific understanding, better technology transfer, more useful policy assessments, improved environmental prediction, more complete monitoring and reporting, or strengthened capacity). Moreover, overall investments in research and development have been declining in recent years for a variety of reasons. Thus, we approach the 21st century with less than might be hoped for in the way of a useful strategic appraisal of how the knowledge and know-how most crucial to successfully navigating the transition toward sustainability is to be identified or of how the capacity to create the needed science and technology is to be developed and sustained.
This report and the processes involved in its preparation and dissemination seek to help reengage the science and technology community as a committed partner in the ongoing global effort to achieve sustainable development. This report is the result of a nearly four-year study of the
National Research Council's Board on Sustainable Development. The Board is composed of 25 members with expertise in diverse topics relating to sustainability, including population demographics, agronomy, agriculture, geography, meteorology, atmospheric chemistry, oceanography, ecology, integrative biology, modeling, hydrology, economics, industry, international finance, energy research, engineering, political science, anthropology, health, and public policy. Since its formation in 1994, the Board has held three workshops (Environmental Barriers to Sustainable Development, December 1996; Decomposition of Complex Issues in Sustainable Development, February 1997; Food Security: Sustaining the Potential, May 1997), two week-long summer studies (Scouting the Rapids, Bar Harbor, Maine, August 1996; Science for the Sustainability Transition, Woods Hole, Massachusetts, July 1997) and other meetings; and the Board has commissioned several papers. The concepts and broad findings of this study were presented at a Symposium on The Transition to Sustainability, which was held at the 135th Annual Meeting of the National Academy of Sciences, in April 1998.
The Board has an ambitious plan for disseminating the messages of the report both within the United States and to the international science and technology communities. In particular, we have suggested that the InterAcademy Panel on International Issues (IAP)an informal network of academies of sciencetake up the issue of sustainability as a major thrust of its program over the next several years. In pursuit of this goal, the Board will present its report as a contribution to an IAP Conference on the Transition to Sustainability, being held in Tokyo on May 15–19, 2000. It is hoped that this conference will set in motion a number of international initiatives that reengage the scientific and technical communities in the dialog on sustainability.
We adopted the metaphors of "journey" and "navigation" in the work reported here with serious intent. They reflect our conviction that any successful quest for sustainability will necessarily be a collective, uncertain, and adaptive endeavor in which society's discovering of where it wants to go and how it might try to get there will be inextricably intertwined. Humanity is no more master of its fate in interactions with the environment than is a canoeist shooting the rapids of a turbulent rivera vivid image used to suggest the challenges to policy in seeking sustainable development.3 But if we do not suffer the delusion of having total control of the future, neither are we fatalists who believe that the skills of the canoeist, boat builder, and mapmaker are irrelevant to the journey's outcome. Instead, as evidenced by many successful explorations from the Beagle to the Hubble, science and technology, we believe, are the necessary complements to inspired leadership, creative imagination, and good luck. The objective of this report is to suggest how the science and tech-
nology enterprise can increase society's chances of undertaking and achieving our common journey of a transition toward sustainability.
We are too aware of the host of shortcomings in the present study. Despite our commitment to international perspectives, except for members from Canada and Mexico, the Board has been essentially a group of U.S. nationals examining a global issue with regard to which local conditions, traditions, and perceptions matter very much. Despite our understanding of how greatly the prospects for any transition to sustainability depend on substantial international political stability and effective domestic governance, we have not explored the political threats or all possible social threats (e.g., terrorism, violence) to such conditions or how they might be mitigated. Despite our belief that poverty alleviation is central to the challenges of sustainability, we have not focused on the economic programs needed to increase productivity of the abjectly poor segments of the world's population. And despite our conviction that taking on the challenges of sustainability is an inherently interdisciplinary activity, we have been better at mobilizing the insights of some disciplines than others in our work. Finally, we are aware that the questions posed and issues addressed in this report are hardly new. Much is known about population, cities, land transformation, agriculture, ecology, and other phenomena that we discuss here only in the most general of terms. We are equally aware that much of what is known is not appliedfor a variety of political, economic, and cultural reasons.
Thus, in this report we have found ourselves both emphasizing the necessity of better applying what is known and arguing that the capacity to produce new knowledge will become increasingly important as pressures on societies and the life support systems of the planet become more intense. More of the same in science and technology or in politics is unlikely to meet the reasonable aspirations of people throughout the globe. But we believe that the scientific and technical community must play an important role in helping societies to realize these aspirations. We believe there are no ready answers to questions of whether or how billions of people in societies all over the globe can achieve their hopes for a better quality of life without severely degrading life support systems. At the same time, we also believe that failure to engage the issues in a truly serious way is shirking both our technical responsibilities and our public duties. Nevertheless, we sit at the Board's table as experts in particular fields, not as advocates of particular causes. This study represents our attempt to seriously engage the issues and to offer a few suggestions for next steps in what appears to be the right direction.
To this end, Chapter 1 develops the Board's concept of a transition to sustainability and the roles of science, technology, and values in outfitting and navigating the journey toward it. Chapter 2 provides an historically
based map of the persistent, large-scale currents of social and environmental change into which the voyage is launched, and with which it will have to contend. Chapter 3 reviews the range of modeling, assessment, and scenario methods available for looking ahead at possible development pathways and their implications for sustainability. Chapter 4 draws on current scientific understanding to outline some of the most significant environmental threats and opportunities that the voyage might encounter. Chapter 5 explores the contributions that appropriate monitoring and indicator systems might make for our abilities to proceed in a turbulent world of surprise and inevitable policy failures. Chapter 6 presents a vision of how knowledge and action could be better integrated in a strategy for navigating toward sustainability, and priorities for research and action to promote the life and livelihood goals of our common journey.
1 UN (United Nations). 1999 (forthcoming). Word population prospects: The 1998 revision. New York: United National Population Division.
2 IUCN (The World Conservation Union), UNEP (United Nations Environment Programme), WWF (World Wildlife Fund), FAO (Food and Agriculture Organization of the United Nations), and UNESCO (United Nations Educational, Scientific, and Cultural Organization). 1980. World conservation strategy: Living resource conservation for sustainable development. Gland, Switzerland: IUCN.
3 William Ruckelshaus, former Administrator of the U.S. Environmental Protection Agency and member of the World Commission on Environment and Development, the well-known "Brundtland Commission," 1989. Toward a sustainable world. Scientific American 261, No. 3:166–74.