Page 59
2
Trends and Transitions
This chapter explores some major historical trends and transitions that might significantly affect the prospects for sustainability over the next half-century. It addresses trends in human development and the earth's environment, and also the interactions between them. In the first part of this chapter, we look at directions in human development, especially the increasing connectedness of economies, peoples, and technologies; the persisting and even growing human diversity in modern cities; the changing patterns of consumption; the emergence of human development as a significant biogeochemical force; and the basic trends in population, economy, resource use, and pollution. In the second part, the chapter traces trends in the transformation of life support systems at local and regional scales, through trends in human-induced changes of atmosphere and climate, oceans, freshwater, land, species and ecosystems, and disease organisms and their vectors.
The trends discussed here are not always constant over time. Instead, long periods of relative constancy are sometimes interspersed with shorter episodes of rapid change. Early in these episodes, changes are often accelerating and may appear exponential. Later, as the episode runs its course or feedbacks cut in, these changes tend to decelerate and may even reverse direction. In between come periods of transition, marked by breaks or inflections in the long-term trends.1 In its examination of critical trends in global change, the United Nations' Department for Policy Coordination and Sustainable Development defines transitions as gradual and continuous shifts in society from one state to another.2
Page 60
We live in an era of such transitions, which are under way to varying degrees in specific places and regions around the globe. In the social realm, the transitions that seem most relevant to sustainability include the demographic transitions from high to low birth and death rates; the health transition from early death by infectious diseases to late death by cancer, heart attack, and stroke; the economic transition from state to market control; the civil society transition from single-party, military, or state-run institutions to multiparty politics and a rich mix of nongovernmental institutions. Environmentally, some of the more significant transitions or breaks in trends in specific regions include shifts from the dominance of particular biogeochemical cycles by natural forces to their dominance by human releases, from increasing to decreasing rates of emissions for specific pollutants, and from deforestation to reforestation.
How should societies think of the relationship between major trends or transitions and sustainability? A series of seven interlinked transitions to a more sustainable world has been identified.3 These were later elaborated and amplified4 as demographic, technological, economic, social, institutional, ideological, and informational transitions. For the most part, the researchers present these transitions as requirements for a more sustainable world: if each individual transition is completed successfully the result will constitute a transition to sustainability.
We take a different tack in this study. In Chapter 1 we argued that the path for a transition toward sustainability could not be charted in advance. Instead, we suggested that it would have to be navigated adaptively through trial-and-error experimentation. We remain unconvinced that any specific set of trends or transitions constitutes necessary or sufficient conditions for sustainability. Yet we think that the triad of goals set out in Chapter 1—meeting human needs, preserving life support systems, reducing hunger and poverty—would guide the successful navigation of a transition toward sustainability over the next two generations. Knowledge of trends and emerging transitions may well prove helpful in attaining these goals; societies must first know the directions of present trajectories in the environment and development. Thus, we begin with trends in human development, then turn to the environmental transformations that have been influenced by human actions, emphasizing the interconnectedness of human development and the environment and the needed shifts in trends for attaining a sustainable future. Specialized studies, named in the text that follows, have addressed trends and transitions for particular aspects of environmental change and particular regions of the world. National Research Council studies related to each developmental sector or environmental issue are provided in endnotes keyed to each section. Our purpose is not to duplicate these extensive treatments found through-
Page 61
out the environmental science literature. Rather, we cite recent studies that present authoritative findings on these topics.
Human Development
Population Growth, Urbanization, and Well-Being
Slowing Growth
The global human population at the end of the 20th century will reach about 6 billion people. With an annual growth rate of 1.33 percent between 1995 and 2000, about 80 million people were added to the planet each year. Current growth rates are falling and have been doing so since the peak global growth rate in the early 1960s of about 2.04 percent per year. Because this slowly declining growth rate is applied to an increasing population base, absolute population growth will remain high for the next few decades. Thus, population size is expected to increase by almost 2 billion between 2000 and 2025, the same amount as in the last quarter of this century.5
Changes in birth rates and death rates over time, a process referred to as the demographic transition, were first studied in Europe. Within two centuries, trends in Europe went from conditions of high birth and death rates to the current conditions of low birth and death rates. In such a transition, deaths first decline more rapidly than births. During that time, population grows rapidly, but eventually it stabilizes as the decline in birth rates matches or even exceeds the decline in death rates. While the general description of the demographic transition is widely accepted, there is much that is debated as to cause and details. Humanity is now in the midst of a global demographic transition that is more rapid than the European transition. Birth and death rates in developing countries have dropped unexpectedly rapidly. The transition in fertility rates in the developing world has declined to 3 births per woman compared to 6 births per woman at the post World War II peak of population growth and is more than halfway towards the level of 2.1 births per woman required to achieve eventual zero population growth. The average number of births for each woman of reproductive age has declined to 3 compared to 6 at the post World War II peak of population growth. The mortality transition in developing countries has also proceeded very rapidly, with life expectancy at birth having increased from 40 years in 1950 to about 64 years today—though this is still well below the 75 years of life expectancy in the industrialized countries.
Today's population growth has immense momentum because large new generations of young people are reaching reproductive age. How
Page 62
much population will grow depends on their choices of family size and their ability to implement these choices. Policies designed to encourage such implementation can slow growth considerably.6 In fact, the recent rates of decline in fertility outpaced earlier projections of demographers, such that the United Nations reduced its mid-range forecast of global population for 2050 from almost 9.8 billion in the 1994 projection to 8.9 billion in the 1998 projection.7 By the end of the 21st century, the world's human population is now projected to reach 9.5 billion.8 Nearly all of this increase—about 97 percent—will occur in the less developed areas of the world.9 (Figure 2.1).
Expanding Urbanization10
Changes in distribution of the world's population over the last 50 years have been relatively small at the global scale (that is, between continents), but relatively large at the intranational scale. Currently, more than half of the world's population lives in Asia, as was the case at the end of the Second World War. The percentage of the world's population residing in Europe and North America has steadily declined, from about
Figure 2.1
Historical and projected human population growth in billions
for less developed and more developed regions, 1950–2050.
Source: UN (1999). Courtesy of the United Nations.
Page 63
30 percent in 1950 to closer to 20 percent at the century's end. The largest proportional gains have been in Africa, which today has nearly 22 percent of the world's population, almost three times its share at mid-century.11
At the beginning of the 21st century, more people will live and work in the urban centers of the world than in rural areas for the first time in history. In 1999, the intranational changes in distribution are mostly related to past and current trends in urbanization. Urban populations are currently growing substantially faster than the population as a whole. The urban proportion of the world's population is thus projected to grow from 45 to about 60 percent in a generation.12 It could well grow to upwards of the 80 percent that now characterizes Europe and Japan in two generations.13 Combined with the rates of overall population growth cited earlier, this means accommodating on the order of 80 million new urban dwellers a year, every year, throughout the transition to sustainability, a feat equivalent to building almost 20 great cities or 10 megacities each year.*
Cities grow because people desire the infrastructure and opportunities that urban areas offer. Jobs, culture, schools, health care, and social services are generally more concentrated and accessible in cities than they are in rural areas. On average, people who live in urban areas receive more income, have fewer children, have better access to education, and live longer than their rural counterparts. But cities are also places of extreme contrast in wealth and opportunity. In some rapidly growing urban areas, it is harder to establish a sense of local community and shared responsibility for the well-being of the poor and hungry; thus in many cities, for the poor, urban life is more difficult, less healthy, and less safe than life in the countryside.14
The global transition to urban life is reflected in increases in both the proportion of urban dwellers and the size of cities. Within these constraints, the growth in the proportion of the population that is urban seems to follow an "s" shaped logistic, leveling off at 80 to 90 percent in industrialized countries.15 The overall percentage of people worldwide living in urban areas increased from 37 percent in 1970 to 45 percent in 1994, and is projected to reach 60 percent in 2025.16 The number of large cities has also grown significantly. In 1950, there were 81 "million cities" (cities with populations between 1 and 10 million); by 1990 there were 270 cities of this size. The number of megacities is increasing rapidly; while in 1950 there were only two megacities, New York and London, by 1990 there were 21 cities of this size, 15 in less developed regions. By 2015,
*A "megacity" is defined as an urban aggregation of 8 million or more inhabitants. A "great city" is a city of 5 million inhabitants.
Page 64
these numbers are projected to increase to 516 "million cities" and 33 megacities. But while the number of megacities has increased, their growth has slowed, suggesting that there may be some ceilings for city size. Twenty-three of these megacities will be located in less developed countries, a dramatic increase over the complete absence of cities of this size in these regions in the 1950s. By 2015, 378 million persons, or 12 percent of the urban population of these areas, will live in megacities.17
Improved Well-Being
As population has doubled and urbanized over the past two generations, the overall well-being of people has substantially improved. Life expectancy has been rapidly extended; lifestyle has been enriched by literacy and education and made more secure economically. The Human Development Index (HDI), reported by the UN Development Program in its annual Human Development Report, provides a convenient and graphic indicator of these changes in the human condition, combining four indicators of well-being in the population of a nation: life expectancy at birth, adult literacy, school enrollment ratio, and real gross domestic product (GDP) per capita. The measures of lifespan, education, and economic welfare are transformed into index values, and the HDI is the simple average of the three index values.18 Figure 2.2 compares the distribution of the world's population on the HDI scale in 1960 and 1992.
The evolving distribution of the human population on the HDI scale reflects the dramatic improvement in the material conditions of human life since the Second World War, particularly in developing countries. Since 1960 life expectancy in the developing world has increased by 17 years, and infant mortality has been cut in half. Access to safe drinking water has roughly doubled to more than two-thirds of all people. Primary school enrollment has increased by nearly two-thirds, reaching 77 percent by 1991. Per capita income has more than tripled. In sum, the developing world has covered as much ground in a generation, in a material sense, as the developed economies did in a century.19 Yet despite these gains, over one-sixth of the population still lives in poverty; and while the percentage of people living below the absolute poverty line of US$1/day in developing countries declined slightly from 30.1 percent in 1987 to 29.4 percent in 1993, the actual number of people living in poverty rose from 1.2 billion in 1987 to 1.3 billion in 1993.20*
Progress has been social as well as material. Women have made im-
*The absolute poverty line of US$1/day is measured as purchasing power parity (PPP) dollars in 1985. World Bank (1999).
Page 65
Figure 2.2
Distribution of the world's population by decile of the Human Development Index
(HDI), 1960 versus 1992. The HDI provides a convenient and graphic indicator of
changes in the human condition by combining four indicators of well-being in the
population of a nation: life expectancy at birth, adult literacy, school enrollment ratio,
and real GDP per capita.
Source: UNDP (1995). Courtesy of Oxford University Press.
portant gains over the past generation in ways that go beyond economic measures, including through narrowing gender gaps in education, increased literacy, and decreased female child labor rates.21 The available measures, however, show clearly that no society treats its women as well as its men. In addition, the relative well-being of different groups in societies remains contentious, as demonstrated by the persistence of underclasses of race, ethnicity, and poverty, and increasing disparities among groups in most societies.
Transitions are also taking place in many other aspects of human development. They include the health transition underlying increasing longevity, with movement away from the infectious diseases characteristic of developing countries to the chronic diseases of industrialized coun-
Page 66
tries. Yet despite these trends, there has been a surprising reemergence of infectious disease even in industrialized countries, with human immuno-deficiency virus (HIV) being the most prominent example. A number of diseases have been connected to technological and environmental changes, such as Legionnaire's disease (air conditioning), toxic shock syndrome (super-absorbent tampons), Lyme disease (changing suburban ecology), and Hanta virus (desert ecology). There may be a transition in education as well—from predominantly informal to formal learning and now to lifelong learning. Educational institutions, especially in the developed countries, are now addressing the needs for lifelong learning. And with the continued development and use of the Internet, especially in the developing countries, education and access to information are both expected to increase rapidly. Development itself was once thought to be a progression of stages.22 But if this is true, it is highly irregular and punctuated by regional differences and periods of economic stagnation and decline (Figure 2.3), by reversals of longevity, such as that of young people in AIDS-affected countries and of men in Russia, and by educational requirements outpacing of educational offerings.
For a Sustainable Future
The persistent trends of growing population numbers but slowing rates of population increase have two major implications. There will be an enormous challenge in meeting the needs of almost twice as many people as there are today in the space of a few decades. But if met successfully, this challenge is not likely to be repeated within the next century or two. Housing and employing the additional people of the equivalent of a thousand additional cities over the next two generations is one part of today's challenge. The 600 million homeless and over-crowded in today's cities suggest the magnitude of the future task. At the same time, building these equivalent cities provides a needed opportunity to replace the current infrastructure and to build anew in an energy- and water-efficient manner.23
The rapid improvements in human well-being over the last two generations make more realistic the prospects of attaining the social goals of a sustainability transition. But the absolute numbers to be fed, nurtured, and educated will be almost twice those of the past two generations. Recent reversals in longevity and sustained periods of economic stagnation in Africa, Latin America, and perhaps Asia argue for caution in the simple projection of trends of improvement into the future. Thus, meeting human needs in ways that provide for future generations is at the heart of the transition to sustainability.
Page 67
Wealth and Consumption24
Growing Wealth—Growing Disparities
Dramatic changes in human well-being are reflected substantially in changes in economic output (Figure 2.3). Trends in GDP—a measure of the total economic activity in a nation's markets—reflect a nation's production and income per capita, and hence give an indication of a country's poverty levels. GDP has been tracked back to 1820 (shown in Figure 2.3 on a logarithmic scale), a date at which the modern era of economic growth began in the view of an economic historian.25
There has been an average worldwide gain in GDP per person by a factor of 7.9 between 1820 and 1992; in the four ''Western offshoots," Australia, Canada, New Zealand, and the United States, economic growth has brought about a gain of more than 17-fold over this span of roughly six generations—doubling economic output within each human lifespan. Even in Africa, the region with the weakest record, economic output per capita almost tripled between 1820 and 1980.
Despite recent gains in GDP per capita, however, economic statistics do not provide a complete measure of societal production. A society that measures its economic attainments only by market transactions misses important activities. For example, family work in households, which is usually done by women, is not counted unless it generates market transactions; and home appliance use is not accounted for in GDP, while appliance repair is incorporated into this measure of economic activity. Pollution, which diminishes the value of ecosystem services and other valued activities and assets, is excluded from conventional GDP accounts as a liability, but appears as a valued economic good as effort, money, and materials are used to respond to it (such as for the repair of a pollution-damaged building façade or the restoration of habitat).
Favorable trends in GDP also fail to account for disparities in the distribution of income. These disparities are widening and are likely to continue to do so in the absence of strong remedial actions.26 The gap is growing between rich and poor countries as a whole and between the rich and poor within many countries. On a global basis, the ratio of the income share of the richest 20 percent to the poorest 20 percent doubled over the past 30 years from 30:1 to 60:1.27 Among the rich countries (OECD countries), there has been a tendency over the last half-century toward convergence of productivity and income levels and a narrowing of disparities in wealth. Between the OECD and the poor or less developed countries, however, there has not been a general trend toward convergence, with the exception of a small but very important subset of developing countries primarily from east and Southeast Asia.28
Page 68
Figure 2.3
Gross Domestic Product (GDP) per capita, by geographic region. "Western
offshoots" are the United States, Canada, Australia, and New Zealand. GDP
is converted to a common standard, 1990 Geary-Khamis dollars, a method
that uses estimates of purchasing power parity to compare national economies.
Source: Maddison (1995).* Courtesy of the Organisation for Economic
Cooperation and Development (OECD).
*See Maddison (1995) Table G-3, p. 228. Appendix B describes treatment of
changes in GDP over time.
Page 69
The relationship between economic growth and income distribution remains controversial among economists.29 Within countries, developing countries have historically had higher levels of income inequality than more developed countries. There is evidence in some countries that increasing development has not contributed to the worsening of disparities in income distribution.30 But in some poor countries that have experienced rapid growth, disparities in earnings and income level have widened. In the developed world—and particularly in the United States—the gap in incomes between the highest 20 percent and the lowest 20 percent of workers has tended to increase since the late 1960s.31
Greater Consumption
Trends toward increasing population and income have also meant trends towards increasing consumption worldwide. In general, extraction, production, and use of energy and materials have increased at rates exceeding the rate of population growth but more slowly than growth in GDP. At the same time, as consumption has increased, use of energy and materials has become more efficient on average.
Varying views of consumption on the part of scientists from different disciplines32 have led to differing interpretations of consumption and its importance. For physicists, matter and energy are conserved, so consumption must be regarded as transformations of matter and energy that produce entropy or disorder. For economists, consumption is spending on consumer goods and services and is distinguished from the production and distribution of those goods. For ecologists, consumption is the pro-cess by which living species obtain energy and nutrients by eating green plants, which produce energy, or other consumers of green plants. And for some sociologists, consumption is a status symbol in that individuals and households use their income to improve their social status through certain kinds of purchases.
To further understanding of human consumption and encourage effective actions toward sustainability, the officers of the U.S. National Academy of Sciences and the Royal Society of London have issued a joint statement on consumption. They choose a variant of the physicist's definition, stating: "Consumption is the human transformation of materials and energy." Their statement goes on to note that "consumption is of concern to the extent that it makes the transformed materials or energy less available for future use, or negatively impacts biophysical systems in such a way as to threaten human health, welfare, or other things people value."33
For consumption as the transformation of energy and materials, data recording trends are limited. Yet there is relatively good global knowledge of energy transformations due in part to the common units of con-
Page 70
version between different technologies. Between 1970 and 1997, for example, the global consumption of energy increased from 207 to 380 quadrillion British thermal units (Btu).34 For material transformations, on the other hand, globally aggregated data exist only for some specific classes of materials, including materials for energy production, construction, industrial minerals and metals, agricultural crops, and water.35 At the national level, however, aggregate analyses are beginning to appear. In the United States, for example, it has been estimated that the mass of current material production and consumption averages well over 50 kilos per person per day (excluding water and extractive waste). Three-quarters of the material flow is split between energy and related feedstock conversion (38 percent) and minerals for construction (37 percent), with the remainder as industrial minerals (5 percent), metals (2 percent), and products of fields (12 percent) and forests (5 percent).36 Of the 50 kilos, about half goes into the air and onto the land as waste. Adding in waste-water and materials associated with extraction may double the total mass of material consumption per person per day.37
In the absence of globally aggregated data, trends and projections in agriculture, energy, and economy can serve as surrogates for more detailed data on energy and material transformation, as suggested in Table 2.1. These data show that over the second half of the 20th century, while world population more than doubled, food production (as measured by grain production) almost tripled, energy use more than quadrupled, and the overall level of economic activity quintupled. Scenarios of current trends show these rapid growth rates of the last 50 years slowing somewhat over the coming 50 years. For example, in one such scenario of current forces and trends (see appendix, Chapter 3), over the next 50 years world population would less than double (1.6x), food and energy consumption would almost double (1.8x and 2.4x respectively) and the economy quadruple (4.3x).
| |||||||||||||||||||||
Page 71
Thus, while future growth in population and consumption is projected to increase less than in the past, both history and future scenarios would predict consumption rate increases at well beyond the rates of population increase. Such scenarios build on a postulated "energy and materials transition" somewhat parallel to that of the demographic transition described above. In such a transition, societies will use increasing amounts of energy and materials as consumption rises, but over time the energy and materials inputs per unit of consumption will decrease.
For a Sustainable Future
Overall, the growth of wealth is as persistent as the growth of population. Like the leveling of population, growth in wealth is perhaps slowing, but barring severe disruptions to the global economy, growth should continue at rates well above that of population. Recent increases in wealth could be seen as leading to a world characterized both by the popular economics maxim—a rising tide raises all boats big and small—and by the increasing division between rich and poor in absolute as well as relative terms. It is difficult to foresee a sustainable future if the latter trend prevails. Regardless of distribution, increased wealth and income imply increased consumption. Sustaining the supply of energy and materials needed to support this level of consumption, making them available where most needed, and addressing the environmental problems resulting from their extraction, consumption and disposal may be the most significant challenges to a sustainability transition, especially as more people adopt the materials-intensive, consumptive lifestyle now enjoyed by most people in industrialized nations.
Technology and Work38
Changing Technologies
On the scale of generations, within the current scientific-industrial revolution, four 60- to 70-year periods of technologically driven economic development have taken place, marked by characteristic sectors of growth, emerging technologies, and concepts of management and industrial organization (Table 2.2). These emerging technologies provoke technological transitions, generally emerging slowly and growing rapidly toward saturation (in logistic growth curve) in the following period. While economists and technology historians differ on the details of period characteristics and timing, and may differ greatly in their explanations of the relationships of these phenomena to large-scale fluctuations in economic growth and recession, there is wide acceptance of the historical sequence of chang-
Page 72
ing and emerging technologies. Most speculative of course is the fifth cycle, of which we are in the early stages and which coincides with the desired transition toward sustainability.
In the current transition, several major technological trends since World War II have combined to change the nature of industry, consumption, and the world. Fossil fuels, including the liquid fuels used in transportation, have been cheap, and in real terms have become cheaper.39 The availability of inexpensive fuel, the rise of the long-range electric distribution grid, the development and widespread commercialization of jet aircraft, and the proliferation of automobiles and long-range diesel trucks, along with the building of major road networks, have all revolutionized the availability of electricity and widespread transportation.
Experience with complex systems and processes of all kinds has led to increased understanding of their management and control, built in part on the research and development of national defense and weapons systems during the post-World War II period.40 These advances include the control of process chemistry, material synthesis, robotics, telecommunications (including power systems, nets, and grids), structural design and construction at all scales, and, most recently, biological technology (both medical and agricultural) and design.
Smaller, More Efficient, and More Mobile
The rise of global communication systems, combining radio, satellite, and fiber systems, has come along more or less in parallel with the rise in transportation. The development of digital computing and the microchip, with continually decreasing size, energy requirements, and cost per digital transaction, have made computation, memory, word, logic, and number processing easily available worldwide. Combined with communications systems, transactions can not only be done at long distances, but computing chores can be divided among sites. Thus, it is no longer necessary for data gathering, analysis, and control to be in the same place. Engineers in different parts of the world can work simultaneously on designs, and a machine can be controlled remotely from any distance.
These technological changes have enabled the improved and systematic pursuit of greater efficiency in the use of energy,41 materials, and money at all scales in large and complex systems. Efficiency in the use of materials has resulted not only from control over materials' properties, but from improvements in their design, which result in more efficiency in their use.42 In addition, reuse of materials through the recycling of old products has become an important and more efficient source of materials.43
Page 73
| ||||||||||||||||||||||||||||||||||||||||||
Page 74
Lessened Work
For those who toil, the great technological revolutions of agriculture and industry initially meant longer hours and harder work. The industrial revolution led to a painful restructuring of agricultural societies, but much later, it led to great improvements in health, longevity, and living and working conditions. For the industrialized world, there has been a dramatic and consistent drop in hours worked over the 150 years of increasingly reliable records. Within the long-term trend, however, there is much variation by age, sex, and education—a reflection of the growing divisions of income and opportunity. For example, while average hours worked have also declined in the United States from 40.2 to 39.2 hours per week over the last 35 years, hours worked (compensated) have risen for college educated men and have dramatically increased for women.44 Indeed, the stresses of the two-worker household and the second job have led to concern about overworked Americans.45
Currently, knowledge of the control and management of complex systems, along with computers and communications, has propelled the use of the robot and automatic control into new and increasingly pervasive forms. This advance has made possible the economic replacement of labor by controllable, semi-intelligent and, perhaps, intelligent machines, first for physical labor, increasingly for routine bureaucratic work, and eventually, perhaps, for most or all routine intelligent work. In addition, societies are beginning to separate the control of processes from the location of the processes themselves. This arrangement enables the separation of the people in control from the entity being controlled, and more generally enables the separation of people from their work. Ultimately, this capability may allow the production of the required goods and services for a very large population by a small number of people who may be in scattered locations.
We are not sure how to organize such a radically changed economic and social system. In most industrialized countries (other than the United States), endemic unemployment has become a way of life and a matter of high concern. Also, mechanization tends to displace lower skilled workers, so unless displaced workers are retrained and new jobs are created, this trend will increase problems for the already poor. Whether such unemployment is only temporary and part of a restructuring between periods of growth or represents a new and long-term result of technological change and globalization is of continuing concern and speculation in the industrialized world.46
Page 75
For a Sustainable Future
Periodically, industrialized countries replace their lead technologies in a process of early adoption, rapid diffusion, and saturation. Industrial history suggests that humanity is in the early stages of still another such transition. The emerging technologies of this transition, for the most part, augur well for needed technological changes as they include evolving energy sources and transmissions, new materials, and the substitution of information for energy and materials. The characteristics of these technologies and the move away from the production of commodities to the provision of services offers the potential for skipping over the dirty (more polluting), intermediate stages of economic development. Trends toward using fewer materials, or "dematerialization," will be furthered by research in molecular and submolecular technologies: microelectronics, biotechnology, and nanotechnology materials. Such technological transitions have always been accompanied by changes and disruptions in the nature of work, even if they lead to an overall reduction in working hours and an increase in unobligated time. Such disruptions may make more difficult the employment of many workers in the next two generations.
Connectedness and Diversity
Increasing Connectedness
The larger population of the future will be closely connected through ties of economic production and consumption, migration, communication, transportation, and interlinking technologies, together often described as "globalization." The expansion of major regional common markets, free-trade blocs, and the ensuing flows of goods, capital, and technology will likely be accompanied by flows of people between countries. New information technologies and mass communication techniques will continue to penetrate many different geographic, temporal, linguistic, cultural, and political barriers.
Since 1950, trade between nations has grown at more than twice the rate of the economy (GNP), and as of this decade, 20 percent of the world's goods and services pass over a border on the road from production to consumption.47 This pace will accelerate as the two current free-trade blocs in North America and Europe are joined by others in Latin America and Asia and global free-trade efforts continue. Prevailing economic opinion sees these rapid increases in trade as the engine of development; in the long run, most participants in such trade will be better off. Yet many in industrialized countries see increased trade as a continuing threat to their own standards of living, imperiling their welfare systems and leading to
Page 76
large unemployment. For the developing countries that are capable of combining their prevailing low wages with flexible and efficient production, the opportunity exists for rapid growth and perhaps a long-term redistribution of the world's wealth with increased trade.
Trade in money and capital now moves quickly with electronic movement of funds, worldwide currency markets, and a 24-hour sequence of open financial markets. Private currency traders set exchange rates, once the purview of governments, and trade $1.3 trillion a day, nearly 100 times the volume of world trade. Private capital flows grow twice as fast as trade, and for U.S. investors, international portfolio transactions exceed 1.5 times U.S. GDP.48
The exchange of words, images, and ideas has also accelerated substantially during the past 50 years. Globally, the exchange of words, as measured by minutes of international telephone calls, quadrupled in the last decade.49 The number of televisions per 1,000 persons worldwide has increased from 153 in 1988 to 228 in 1995.50 The number of Internet users worldwide has increased from 26 million in 1995 to 205 million in 1999 and is expected to reach 350 million by 2005.51 With the exchange of words and images comes the transfer of ideas and culture, which in current technology is dominated by English words and images of industrialized countries' lifestyles and their consumer products.
The spread of cultural ideas about the desirability of consumption into distant places enlarges markets and fuels energy and materials transformations at rates far exceeding population growth. While modern technology enables communication that may be freighted with these values, it also distributes a culture of environmental concern that builds on universal concerns for the fate of the earth. Increased communication links those who have environmental concerns to common international efforts, to shared information, and to growing numbers of environmental NGOs (nongovernmental organizations). Such links have had a large impact on shaping public attitudes and opinions, and ultimately on influencing public policy and political will. Changes in attitudes and beliefs, influenced by the proliferation of communication, seem under way in at least three important sets of ideas: (1) that cohabitation with the natural world is necessary, (2) that there are limits to human activity, and (3) that the benefits of human activity need to be more widely shared.52
Flows of people—temporary, permanent, and forced—have also increased, although most of these movements are poorly measured. According to the most recent worldwide estimates of the number of international migrants, dating from 1990, perhaps as many as 120 million people cross a border annually, or about 2 percent of the world's population. This figure represents a growth rate in migration of 1.9 percent per year since 1965, when the global estimate of cross-border migration was 75 million
Page 77
persons per year. The percentage of people who migrate with the intention of becoming permanent or long-term residents of a foreign country remained relatively stable at between 2.1 and 2.3 percent of the world's population from 1965 to 1990; but the number of countries hosting a significant proportion of migrants (e.g., more than 300,000 migrants or more than 15 percent of population 1965–1990) has increased.53 Within countries, massive migrations continue, often from countryside to city, from places of limited to greater opportunity. Between 40 and 60 percent of urban growth is attributed to internal migrants from the countryside.54 Increasingly, some movements of populations are forced, with about 20 million refugees in 1997 seeking asylum in other countries and more forced to move within their own.55 The rate of increase in refugees is more rapid than the rate of increase in world trade.
The rise of the global transportation network has made the location of most material goods nearly irrelevant (though this does not equate with access); generally, products are easily transportable and only land and ecosystems stay put. Fresh fruit and vegetables, fish and meat, as well as furniture, vehicles, building materials and other products may reach their consumers from anywhere in the world. Because the rise of the computer and the global communication network have made knowledge widely available, worldwide distribution has been greatly facilitated, though inaccessibility of material goods continues to be a serious problem for many countries with mostly lower income populations.
The increasing connectedness of the world population also presents environmental threats.56 The rapid movement of peoples and products makes possible the rapid transmission of infectious diseases that affect people, crops, and livestock and of biological invasions that destroy native biota as well as crops.57 Environmental changes related to extractive processes for mines, fields, forests, and the sea are accelerated, as tropical forests are exploited for industrialized country consumption and as coastal forests and farmlands are destroyed in shrimp aquaculture. Environmental problems associated with manufacturing are exported to countries with weak environmental regulations or where rapid industrialization uses older technologies that do not incorporate recent advances in energy efficiency or industrial ecology. Most feared of all may be the rapid increases in consumption fueled by aggressive marketing and rooted in cultural change as well as economic growth. Often these changes combine to bring about destructive effects, such as the recent fires in Southeast Asia, where drought from El Niño, fires to clear land for palm oil production, and massive urban air pollution combined to shroud portions of four countries in health-impairing, accident-causing smog.
Page 78
Persistent Diversity
Although the exchange of words, ideas, and cultures will increase in the next half-century, the increasing connectedness of the human population will not make all people alike. New opportunities for human development may increase personal and societal diversity as well as the availability of material things. Places of wealth or opportunity toward which people and products gravitate become more diverse by drawing people from different regions and cultures.58 In response to such increased connectedness of diverse peoples, and the corresponding infiltration of outside values into societies, strong ethnic, nationalistic, and religious movements can emerge to counteract homogenization and reassert traditional cultural values.
Trends in urban centers, which hold wealth or opportunities toward which migrants are drawn, show that diversity is increasing in cities: there are 20 or more languages available to schoolchildren for bilingual education in some countries, and the shelves of supermarkets are laden with foods from many parts of the world. With the collapse of the Soviet Union came a dramatic increase in nationhood, but this was only the latest in a process of decolonization seen since the end of World War II, with the number of nations more than doubling from the 73 countries at that time to the 190 today. In these newer nations, old claims persist and new claims arise for regional autonomy or national independence. The much-reported resurgence of Islamic religious vitality and conflict tends to obscure equally tense religious differences between and within the majority of the world's religions.59
Are these differences among people and nations—in wealth, ethnicity, religion, and opportunities, differences that divide people, create inequities, and encourage conflicts—likely to persist and perhaps grow? Current trends in some measures of human development, such as the earlier-discussed trends in health and human rights, show decreasing inequity; wealth measures are indicating stable or growing disparities; and either despite or because of the Cold War's end, conflicts remain and emerge, and may be increasing. Some observers also see trends in the diminution of social capital—in the common bonds, activities and organizations that create community and mutual support.60 In addition, it is not apparent whether increasing divisiveness is a persistent trend, similar to trends in connectedness, or an artifact of communication in which news of conflict and division is selectively and rapidly disseminated, or has been constant and is only more readily revealed as greater global divisions diminish.
Page 79
Changing Institutions, Shifting Power
Connectedness and diversity are reflected in institutional innovations and shifts in power.61 At a global level, new institutions of governance have emerged, transnational corporations and financial institutions have grown and consolidated, and NGO networks have collaborated and expanded. At the subnational level, government has devolved, privatization is common, and civic society in many places has been strengthened. Power has shifted from the central, national state both upwards to the global and downward to the local as well as to civic society and private enterprise.
The power shift from central government is paralleled by an expansion of private property rights and market relationships. In less-developed countries, such shifts have been marked by declines in shared common-property resources and increases in individually held and marketed resources.62 Labor relationships have similarly shifted through various institutions from labor tied to place or person to labor free to circulate, for example, in China.63 In the former socialist economies of Europe and Asia, and in the social democracies of Europe, once centrally held property is increasingly privatized.
For a Sustainable Future
Increasing connectedness will fuel growth in some parts of the world, diminish it in others, and amplify the forces that drive increased consumption. In addition, it will export to some developing and recently industrializing countries many of the environmental problems of the industrialized world and, with some delay, the institutions and technologies to control them. Connectedness, while creating common elements of culture in most places and increasing the similarity of places, can also increase diversity, particularly in urban areas that attract migrants. The diversity of the human experience offers possibilities for alternative lifestyles and new possibilities of addressing our common future, but divisiveness between diverse communities makes common tasks much more difficult. Ultimately, divisiveness may lead to war—the greatest threat to human development and the environment.
Page 80
Human Action and Environmental Transformations
Rates, Scales, and Multiple Stresses64
Rapid Global Change
The world has experienced human-induced changes in local, regional, and global environments for much of the past 10,000 years, but most of that change has occurred during our lifetime.65 Recent analyses comparing modifications in the environment over the last 300 years to changes over the last 10,000 years demonstrate the unprecedented nature, scale, and rate of human-induced changes in the earth's environment.66 In the last 300 years, humankind has demonstrated the capacity to change the environment on a scale that equals or exceeds the rate of natural environmental changes, as human population, economic growth, and technological capability have combined to create human-influenced ecosystems on much of the land and coastal areas of the earth.
Human actions have significantly altered biogeochemical cycles, of both land and water, along with biotic diversity. In 13 worldwide measures reconstructed by the Earth Transformed67 project—including carbon, carbon tetrachloride, lead, nitrogen, phosphorus and sulfur; deforested area, sediment flows, soil area loss, and water withdrawal; and flora, marine mammals, and terrestrial vertebrates—most of the change has been extraordinarily recent. For 10 of the 13 measures, half of all the change over the last 10,000 years took place within our lifetime (Table 2.3). Overall, since the dawn of agriculture roughly 100 centuries ago, an area the size of the continental United States has been deforested by human actions. In addition, half of the ecosystems of the ice-free lands of the earth have been modified, managed, or utilized by people. Water in an amount greater than the contents of Lake Huron is withdrawn each year for human use. As a whole, many flows of materials and energy that are removed from their natural settings or synthesized now rival the flows of such materials within nature itself.
Other related studies by biologists and systems analysts have assessed the degree to which humans dominate ecosystems.68 For example, researchers69 analyzed sunlight as the basic source of energy for nearly all life on earth. Using three different definitions of the proportion of the net primary productivity that should be assigned to human ''appropriation," the study suggested that as much as 40 percent of the photosynthesis on land, in the form of plant biomass, is being used by humans. Using the same framework, researchers70 estimated the fraction of fresh water "co-opted" by humans; while this estimate depends on assumptions that de-
Page 81
| ||||||||||||||||||
fine how various flows of water are to be counted, their estimates range upward from 23 percent of the annual flow accessible to humans. A related estimate of water needs71 suggests that growing food to feed the existing human population a vegetarian diet already claims half the water used by humans. The most recent of these studies72 summarizes the body of work on human dominance of ecosystems.
The central thrust of these analyses is that humans are now recruiting significant fractions of sunlight, fresh water, and life forms to their purposes, with the fraction rising to over half in some instances. These estimates, while inexact, portend that expansions in the human claim on the planet's life support systems cannot be indefinitely extended, especially as human numbers rise through the remainder of the demographic transition.
Taken together, do these massive and recent human-induced environmental changes threaten the life support systems of the earth for human life? Although for the earth as a whole the entire system has not likely been irreparably damaged, in some regions, according to available studies, environmental threats from human activities loom. In a recent comparative study, six of nine regions—located in Brazil, China, Europe, Indonesia, Kenya, and the United States—were found to have "current human uses and levels of well-being [that] appear to be environmentally unsustainable over the middle-to long-term future."73 Two regions—one
Page 82
in Nepal and one in Mexico—appear environmentally unsustainable in the near-term future, and the Aral Sea region in Central Asia is already unsustainable.
In addition to regional and global indications of unsustainability, the intensity of human use of the natural world makes it virtually certain that environmental threats will continue and that surprises are inevitable, for example, in the form of new and reemergent plant and animal diseases. By definition, environmental surprises cannot be foreseen, but the structural conditions that encourage their emergence and proliferation can be described. Environmental surprises should be expected as trade continues to expand, with the accompanying movement of peoples, life forms, and goods; as new molecular-level technologies in biology and materials are deployed; as older technologies are applied in new, untried settings; and as humans respond to existing environmental problems, in responses that have sometimes produced unexpected and unwanted consequences.74
Shifting Problems and Policies
In the upcoming decades, there may also be shifts in the nature of environmental problems, their scales, and the societal policies to reduce or ameliorate them. Since the 1950s, 6 of the 13 indicators shown in Table 2.3 have changed at a decelerating rate, while the remainder still seem to be accelerating in change.75 The deceleration occurs for those environmental components most subject to government regulation, suggesting increased efficacy of environmental policies.
The idea of environmental transitions was framed in an analysis76 that identified three different trajectories that environmental problems may follow with a rise in per capita income. Characteristic problems of developing countries such as inadequate water supply and sanitation decline with rising income. Air and water pollution increase and then decrease (an inverted U-curve) as governments with seemingly greater resources have regulated and taxed enough facilities to bring down pollutant concentrations. But as income increases, so apparently does material consumption, which leads to increased trash production and carbon dioxide emissions. These activities show no signs as yet of abating.
These curious irregularitiesm77 have stirred a great deal of debate by suggesting that, in some cases, environmental quality can improve with prosperity. The inverted U-curves have come to be called "Kuznets" curves by analogy with a pattern noticed by economist Simon Kuznets in the 1950s—income inequality appeared first to rise and then to fall in the course of early industrialization.
These findings suggest that a transition toward sustainability may be characterized by a change in the relative importance of environmental
Page 83
problems, with the most serious concerns perhaps shifting from dirty water and lack of sanitation, to air and water pollution, and then to climate change. The scale of concern may increasingly shift from household, neighborhood, and village, to urban area and region, and finally, to region and the world. Policy emphases should correspondingly shift, whether in the areas of public health, pollution abatement, source reduction, or efficiencies in reducing consumption and reusing and recycling materials.
For a Sustainable Future
Human domination of natural systems is already so extensive in many places, however, and our dependence on natural resources so deep, that permanent management of ecosystems appears to be the only practicable alternative for a sizable fraction of the natural world. Instituting and sustaining management on large scales to serve so many partially competing ends is a feat achieved in only a few places for relatively brief periods. At smaller spatial scales, however, and for some significant problems, including safe drinking water and industrial air pollution, there are encouraging signs of effective control as societies marshal the social will and economic capabilities to address these problems. Transitions in the relationships between humans and nature are inevitable; whether they will result in a sustainable economy and ecology cannot be discerned from the trends themselves.
Global Atmosphere and Climate78
Declining but Stabilizing Stratospheric Ozone
Human activities have altered the chemical composition of the atmosphere locally, regionally, and globally. Although these changes are small in terms of percentage changes, even a small amount of change in the composition of the atmosphere can have noticeable and serious environmental impacts. These effects result in part from the high reactivity of compounds such as ozone and oxides of sulfur and nitrogen, and in part from the fact that the greenhouse gases and stratospheric ozone play crucial gatekeeper roles for the earth's life support systems.
Human use of chlorofluorocarbon gases (CFCs), beginning in the 1930s, has released a small but potent quantity of these industrial chemicals into the atmosphere. As CFC molecules drift to the upper atmosphere, they are broken down by solar ultraviolet radiation and release chlorine atoms. These atoms interact catalytically with the layer of ozone (03) in the stratosphere, with each chlorine atom on average destroying a
Page 84
large number of ozone molecules before reacting to form relatively inert compounds that are subsequently transported down to Earth's surface and removed in precipitation and on land and water surfaces. For this reason, a small quantity of CFC gases can have a substantial effect on the stratospheric ozone layer. This layer is an important component in the life support systems of the planet in that it screens all life forms from harmful solar ultraviolet radiation.
The discovery of the atmospheric chemistry of the chlorofluorocarbons, followed just over a decade later by the discovery of the seasonal ozone hole over the Antarctic and its chemical explanation, spurred governments all over the world to enter into a treaty to reduce CFC emissions.79 In response, the Montreal Protocol of 1987 and its subsequent amendments have led to sharply decreased emissions of CFCs and other ozone-destroying compounds, including brominated chemicals such as halons. Atmospheric amounts of several of these key compounds are now observed to be decreasing.80 However, data on total stratospheric ozone amounts do not yet clearly demonstrate recovery of the ozone layer.
Increasing Greenhouse Cases—A Warmer Climate
Greenhouse gases, which include carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and halocarbons (CFCs, HFCs, PFCs), are expected to modify the earth's climate, with effects unfolding over time scales of decades to centuries.81 These gases have increased steadily with the use of fossil fuels over the course of industrialization, with a total increase in CO2 of more than 30 percent over preindustrial levels in the past century and a half. Ninety percent of energy sold today comes from fossil fuels.82 Total energy use has tripled in the past 50 years, with the share from nonfossil fuel sources slowly rising as the use of nuclear generators and hydropower has increased.
While carbon dioxide and methane increases are expected to have the biggest impact on climate, some of the most uncertain aspects of climate change are the direct and indirect radiative effects of sulfate and carbonaceous aerosols (particles) in the climate system and their related impacts on tropospheric chemistry and human health. These particles enter into the processes forming clouds, which result in more reflection of solar radiation and more absorption of the infrared radiation. The magnitude of this effect is uncertain but is believed to be substantial. The increase in global average surface air temperature from 1860 until the present is shown in Figure 2.4. Recent decades are the warmest in the instrumental record. The global temperature increase is generally consistent with
Page 85
Figure 2.4
Annual global mean temperature for land areas from 1861 to 1997.
The curve shows anomalies with respect to the mean temperature for
the 30 years 1961-1990.
Source: Global Historical Climatology Network (GHCN); Peterson
and Vose (1997). Courtesy of the National Climatic Data Center.
climate model calculations of the combined effects of the observed increases of greenhouse gases and aerosols. Because of the long atmospheric lifetimes of most greenhouse gases and the thermal inertia of the oceans, it is widely acknowledged that even rapid reductions in contemporary greenhouse gas emissions would still leave the world committed to significant climate change at an average rate of warming greater than any seen in the last 10,000 years. Of course, most places on earth would not experience the global average. Rather, they would likely experience more extreme weather patterns of variation due to the regionality of climate and sea level change and the impacts of natural variability at the annual to decadal scale. These changing finer scale patterns cannot now be predicted with confidence, but could eventually entail significant changes in the frequency of heat stress episodes, the severity of droughts, and the competitive balance among species.83
Page 86
Increasing and Decreasing Regional and Local Air Pollutants
Industrialization has been accompanied by increases in air pollution, mainly from the combustion of fossil fuels. These pollutants are mostly redeposited locally, although there are important cases of long-distance transport of pollutants by horizontal and vertical winds. Tropospheric ozone—the ozone in the lowest and densest part of the atmosphere where humans live—is produced by the oxidation of many precursor gases, including carbon monoxide, nitrogen oxides, and hydrocarbons. Other important pollutants, including oxides of sulfur and aerosols such as soot, result from the burning of coal and oil. As noted above, some of these pollutants have been successfully managed regionally as income levels have risen.
Over the past century, as industrialization has spread from the OECD countries into the developing world, measured amounts of ozone at the earth's surface and throughout the troposphere have increased and then stabilized, as pollution-control technology has been developed and adopted. These trends slowed and/or vanished in North America and Western Europe during the 1980s and 1990s.84 By contrast, tropospheric ozone amounts continue to increase over Japan. The likely cause is increasing emissions of ozone precursors, principally nitrogen oxides and carbon monoxide from combustion in China, Taiwan, Korea, and Japan.85
Similar patterns have been observed in sulfur and nitrogen compounds, the principal pollutants in acid rain.86 In at least one advanced country, data show that reduced sulfur dioxide emissions have led to decreased amounts of sulfate in atmospheric aerosols (and presumably to decreased precipitation of sulfuric acid). Researchers87 reported that aerosol sulfate measurements from 1979 to 1996 at Whiteface Mountain and Mayville in New York declined about 45 percent and 30 percent respectively, from corresponding amounts averaged over the period from 1981 to 1991. During this time, upwind emissions of SO2 from the U. S. Midwest declined by about 35 percent.
The data records are less clearly interpreted for carbon monoxide in the troposphere.88 Measurements of CO in surface air show decreases in the early 1990s, and globally averaged amounts have decreased by 2 to 5 percent per year.89 The cause of this decrease is not clear.
For a Sustainable Future
It has been possible in some instances to manage pollution of the atmosphere so that damage is stabilized or even reversed. This is taking place at the global scale with stratospheric ozone, at the regional level for acid rain in Europe, and in numerous urban areas via regulation and
Page 87
pollution control technology. That pollution control has been possible in these instances does not, of course, assure sustainable future conditions in the atmosphere, but clearly shows the direction of what is possible. In the short run, however, air quality conditions continue to worsen in a large number of areas, especially in Latin America and Asia.
There is a large international research and monitoring effort to study the atmosphere and its modification by humans. Most of the expertise is concentrated in the developed countries, however, and an important element of a transition toward sustainability will be continued effective transfer of scientific and technical resources to developing countries.
Managing climate change in a sustainability transition will have to account for the trend of rising energy consumption, together with the predominant role played by fossil fuels up to now. Large-scale departures from that trend will entail far more than a new technology, including global markets and infrastructures to handle new means of generating energy and to integrate them into existing technological systems and markets. In response to the 1992 Framework Convention on Climate Change goal (see Chapter 1) of stabilizing "atmospheric concentrations of greenhouse gases at a level which would prevent dangerous human interference in the climate system," governments have so far only adopted the near-term objective of stabilizing emission rates. This means that the atmospheric concentrations of greenhouse gases will continue to grow. While scientists cannot predict exactly the impacts of such trends, persistent addition of greenhouse gases to the atmosphere is very likely to make achieving a sustainability transition harder. The changes in energy use required to substantially mitigate the risk of global climate change will require considerable changes in existing infrastructure and institutions. Comparably significant changes may be required to reduce the vulnerability of societies to such climate changes that do occur.
Oceans90
Stable Oceans, Changing Coastal Zones
Although humans have intensively exploited fish and other living resources, mined minerals, and released pollutants, the open seas have so far been relatively less affected by human activities.91 This fact is a reflection of the size of the world ocean, which covers 71 percent of the earth's surface, and the relatively modest presence of humans on the seas so far. An important exception is the status of some high seas fisheries (e.g., swordfish and orange roughy) which are harvested at unsustainable rates; and many estuaries, coastal zones, and confined seas have been degraded or extensively modified, with few instances of successful recovery. Also,
Page 88
the effect of long-term changes in atmospheric forcing on oceans, as perhaps may be seen in the recent greater extremes of El Niño and the widespread environmental consequences, is increasingly of concern.
Humans have extensively altered coastal zones, largely as an indirect effect of developing adjoining land and littoral areas.92 As the near-coastal human population, including the residents of most of the world's mega-cities, continues to increase, these effects will increase. In addition to residents of the coastal zone, many additional people flock to the coast for recreation and tourism, increasing the environmental pressures from roads, commercial development, waste disposal, marinas, and other recreational facilities. The resources of coastal ecosystems are very often intensively exploited for seafood and energy resources.
Coastal ecosystems are often affected by activities that occur far inland, through changes in the delivery of water, nutrients, and chemical contaminants from rivers and atmospheric deposition.93 Large areas of important coastal waters such as the Chesapeake Bay, the northern Gulf of Mexico, Long Island Sound, and Lake Erie, in the United States and the North Sea and the northern Adriatic Sea, in Europe have experienced increased plankton blooms and depletion of dissolved oxygen as a result of nutrient overenrichment from both point-source (sewage discharges) and diffuse inputs (agricultural and urban runoff and atmospheric inputs) during the latter half of this century. At present, coasts are affected by the continued rise in sea level worldwide, at about 1.8 mm. per year for over a century. These values are an order of magnitude greater than the average experienced over the last few millennia.94 This worldwide rise, if combined with local land subsidence, results in a large local rise in relative sea level, flooding of coastal areas, and increases in beach erosion. Also, coastal environments are among the areas most susceptible to the consequences of global climate change that could affect sea level, freshwater runoff, frequency and intensity of storms, and temperature patterns.95
Other longer term physical and biological responses of the oceans to climate change are possible, including the disruption of North Atlantic deepwater formation, a condition that has been associated with significant climate variability in the past, and the effect of warming polar oceans on sea-ice melting, which can alter ecosystem processes including primary production.
Declining Valued Marine Fisheries
The human impact on marine life was long assumed to be small because of the great numbers of species in the oceans and their large populations. This view has been proven wrong as fisheries around the world
Page 89
have been overexploited during the last 40 years.96 In the United States, approximately one-third of those species whose status is known are over-fished.97 Studies in marine ecology and fisheries demonstrate that humans have caused at least local extinctions, together with many other ecosystem modifications that are difficult or impossible to reverse.98 Along with the declines in catch, it is likely that ecosystem impacts caused by humans are increasing in severity.
Current levels of fisheries overexploitation are associated with the failure of fishery management to contain human fishing pressures within sustainable limits.99 Fishery failures are usually attributable to direct causes, including a lack of political will, scientific uncertainty, destructive fishing practices, and excessive levels of fishing capacity that create pressure to abandon conservative levels of exploitation. The 1996 passage of the Magnuson-Stevens Fishery Conservation and Management Act in the United States introduced a number of more conservative elements into the U.S. federal fisheries management system, including a requirement to eliminate overfishing, to define and protect essential fish habitat, and to reduce bycatch.100 The next reauthorization, due in 2000, is likely to further broaden the precautionary approach to fisheries management and to strengthen coordination with other statutes that protect marine species.
Human activities affect marine species indirectly as well, notably through the degradation or modification of habitats used by marine species at some point in their life cycles. Pacific salmon, for example, a migratory species that spawns in freshwater, has been substantially affected by logging, grazing, farming, urbanization, and dams in the U.S. Pacific Northwest.101 More generally, sedimentation and pollution resulting from the large-scale conversion of land and coastal regions to human purposes (e.g., conversion of mangroves to rice farming) have affected coastal areas and the composition of river waters (e.g., runoff from poultry farms as in Chesapeake Bay) flowing to the sea. These actions have affected the abundance and diversity of marine life through changes in the quantity of coastal wetlands and the quality of estuarine waters, a primary source of marine productivity.102
Fishing itself can affect marine ecosystems, especially the habitats of fish and other marine species, by changing bottom topography and associated benthic communities. Large-scale changes in coral reef ecosystems in the Caribbean and in community structure in the Bering, Barents, and Baltic seas, on Georges Bank, and in other regions have been attributed to fishing. Together with increasing introductions of exotics and increasing pollution, fishing and other human activities will continue to effect the loss of goods and services from marine ecosystems.103
Page 90
For a Sustainable Future
Although the open seas have been modified comparatively little by human activity, there are serious problems that need to be addressed for a successful transition to sustainability, including the unsustainable harvest of some marine fisheries. There is no indication that humans will moderate their transformation of the nearshore marine environment. Coastal zones, along with tropical forests, are the regions of the earth currently undergoing maximum human transformation. The trend of the marine environment is, in sum, one of continuing human modification, much of it inadvertent.
Despite serious attempts at conservation and management104 the unsustainable use of fisheries persists, sometimes until the fishery collapses economically. For decades, scientists have called for managing fisheries from an ecosystem perspective, and some steps have been taken in this direction that appear to be feasible in some fisheries.105 In many other instances, the appropriate application of ecosystem concepts remains difficult or impossible under current institutional conditions.106 Sustainability of the oceans will above all require an integrated and adaptive ecosystem-based approach to management, incorporating such elements as conservative single-species management, reductions of excess fishing capacity and assignment of fishing rights, establishment of marine protected areas and appropriate institutions, consideration of bycatch and discards in fishing mortality estimates, and other information needs.107 Such an approach may help to ensure the production of goods and services from marine ecosystems, and, at the same time continue to provide food, revenue, and recreation for humans.108
Fresh Water109
Slowing Global Withdrawals, Regional and Local Scarcity
From 1940 to 1990, withdrawals of water for human use (i.e., removals from a natural source for storage or use) increased by more than a factor of four, reflecting a long-term trend of increasing withdrawals per capita.110 The rate of withdrawal, an average of 2.5 percent per year, has been more rapid than population growth. Per capita availability of fresh water on a global basis fell from 17,000 m3 in 1950 to 7,300 m3 in 1995,111 while per capita freshwater demand rose until the mid-1980s.112 One result was a large global investment in and construction of dams and transport systems. However, since the mid-1980s, absolute water withdrawals have slowed and per capita water withdrawals have declined worldwide.113 In the United States, water withdrawals in 1995 had
Page 91
declined nearly 10 percent from their highest level in 1980. In fact, actual global water withdrawals have been consistently less than estimates of withdrawals predicted between 1967 and 1996.114 Nevertheless, with increasing population growth, there is no reason to be complacent about water withdrawals.
Although fresh water is a renewable resource (through groundwater recharge, surface runoff from local rainfall, in-flow from nearby regions) and global water supplies are abundant, regional water resources are unevenly distributed among countries, and local supplies or stocks are finite. In some areas with low supply, the continued high withdrawal causes serious local water shortages and harm to aquatic ecosystems.115 Nearly one-third of the world's population is found in countries stressed by pressure on the availability of water resources (i.e., consumption levels that exceed 20 percent of available supply).116 The unmet demand in developing countries for household water use remains high—nearly 1.2 billion people do not have access to safe and reliable water.117 Developing countries that have both high water stress and low per capita income have the greatest potential problem of unmet demand, because they use most of the available water for intensive farm irrigation, have few financial resources to shift investment from irrigation to other sectors, and have few pollution controls.118 Thus, most of the nations especially vulnerable to water scarcity are located in the arid or semiarid regions of Africa and Asia and the Middle East.119 Altogether, 26 countries—approximately 232 million people—are considered ''water scarce."120
While water is a renewable resource because of the characteristics of the hydrologic cycle, various human actions can lead to nonrenewable or unsustainable water use. Groundwater aquifers can be pumped faster than the rate of recharge,121 leading to declining aquifer levels, land subsidence, or, in coastal areas, contamination from salt water intrusion. Similarly, land use and landscape modifications can affect both the quality and quantity of water in a watershed that is available on a renewable basis.
If treated properly, water can be reused so that withdrawals alone do not accurately measure the degree of human pressure on water resources.122 As the quality of water declines because of increasing water contamination (e.g., from human settlements, industry, and agriculture) and land use changes (e.g., from practices that enhance water runoff from the surface, such as clearing forests or paving roads), however, water supply declines. Competition for scarce water resources, especially between rural and urban users, is increasing, with potentially serious implications for food production as urban areas with greater political strength will tend to out-compete local farmers.123
Where water is abundant, economic growth has been accompanied
Page 92
by the expansion of infrastructure to transport fresh water and wastewater. Methods of treating wastewater to render it clean enough for reuse by human settlements downstream have also been developed, usually after a delay of decades.124 Water is expensive to transport, and the large capital investments required to move water usually dictate wells and recycling when there is not enough surface water at hand. Meeting the needs of development in such regions of surface water scarcity requires that water come from wells, sometimes from nonrenewable aquifers, from distant rivers and, more recently, from careful husbanding and recycling.125
Shifting Usage, Declining Quality, Increasing Efficiency of Use
As countries have industrialized, there has been a shift in water usage from agriculture to industry, commercial activity, and households, with domestic consumption increasing greatly with increasing affluence.126 This trend is expected to continue with the share of agricultural use of water declining, though the amount of water use in agriculture is expected to increase with increasing worldwide demand for food, especially in developing countries.127
Water use per person appears to rise with income to a point beyond which additional income per capita leads to declining per capita water use in households and industry. But water use per capita is not in direct proportion to national income, because increased use in one sector (industry) may be offset by decreases in another (agriculture) in the course of development. Increased efficiency in water use can play an important role. In recent years, rising per capita income in higher-income developing countries is correlated with lower per capita consumption of water in industry and households.128
Water quality has steadily improved in most of the developed countries because of regulatory controls and investments in water treatment and sanitation. However, water quality in developing countries is declining, especially in urban areas, because of rapid industrialization and increased contamination by toxics.129 In many areas of the world, water withdrawn for human use is groundwater from wells and natural outlets. Industrial toxins, if not carefully controlled, can spill and enter aquifers, contaminating groundwater. Where groundwater reserves are a major source of water supply (e.g., 50 percent of domestic supplies in Asia), expanding mining or industrial development can lead to problems of contamination.130
Water is a basic human need and the failure to provide clean drinking water and sanitation services to all is one of the most fundamental failures of development in the 20th century. As of 1994, according to the UN, 1.2
Page 93
billion people lacked access to clean drinking water, while nearly 3 billion lacked access to sanitation services. This failure to meet basic human needs for water causes between 5 and 10 million deaths a year, mostly of small children and the elderly, from water-related diseases. Some efforts to eradicate water-related diseases have been successful. For example, guinea worm (dracunculiasis), which is a parasitic disease that can be eliminated through providing clean drinking water, is on the verge of elimination in Africa and Asia where it used to be prevalent.131 Cholera is not as easily eradicated with improved water supply, but it can be prevented by removing the bacterium with sewage and water treatment and treated by oral hydration therapy. However, fatality rates are often high in parts of Africa and Asia because of the lack of treatment facilities and preparedness.132 In 1991, an extraordinary spread of cholera in Latin America has been linked to dumping of contaminated bilge water from a ship in the harbor in Lima, Peru, the lack of adequate facilities for providing clean water and sanitation, and the increase in algal blooms resulting from the warmer water, heavier rain and higher nutrient runoff associated with El Niño.133
For a Sustainable Future
In a transition to sustainability, water use seems likely to rely increasingly on efficiency in use and supply, closed cycles, more effective means of preventing and controlling water pollution, and more appropriate water pricing.134 These trends also imply more efficient use of energy, the continuing decline in the construction of large projects, and increasing innovation and use of water-saving technologies. Thus, the stresses on water accessibility and use will require that water use must grow evermore efficient and that balances must be struck to achieve a successful sustainability transition. For example, water could increasingly be a source of conflict between users (agriculture, industry, households), between ecosystems and regions (uplands, flood plains, dam sites, cities), and nations (Middle East, Nile valley, South Asia) in places of potential regional and local scarcity. Where hydrological systems match regions rather than national boundaries—for example, in the Middle East—efforts are needed to forge regional plans for water resources.135
Land136
Increasing Intensification of Agriculture
Over the past 300 years, land planted with agricultural crops has increased nearly fivefold, to about 15 million km2.137 This net increase in
Page 94
cropland has been accompanied by a net decrease of forested land of similar magnitude. Another vast area of land has been lost to productive use since the emergence of agriculture 10,000 years ago, as a result of erosion, salinization of irrigated lands, desertification, and permanent conversions of arable land to cities, roads, and reservoirs. During the 20th century, the rate of loss of productive land has accelerated sharply, to a rate of 70,000 km2 per year, an annual loss the size of Sierra Leone.138 An underlying factor in the acceleration of farmland conversion to nonagricultural use is that, with a rapidly growing economy, the market value of land for alternative use is growing at a far faster pace than its value for agricultural productivity. Except for a very elite set of crops, the value of land for photosynthesis will be less than for most alternative uses, considering the cash and energy flows through most nonagricultural enterprises per unit of land.
The discussion of hunger earlier in this chapter records an extraordinary achievement of the 20th century rising agricultural outputs that have outpaced human population growth and dramatically reduced the incidence of famine. This advance has been accomplished over the last 50 years by the large-scale application of scientific and practical knowledge to farming, with dramatic results in many poor nations such as India and economically impressive rises in agricultural production in rich countries such as Australia and the United States. The intensification of agriculture has been rooted in the identification, development, and widespread adoption of high-yielding varieties of cereal crops, the use of fertilizers and mechanized equipment in developing countries, and irrigation. High-yield varieties and fertilizers form the foundation of the Green Revolution in Asia and Latin America.139 The declining real cost of food for the past several decades, associated with more efficient agricultural production, has increased food accessibility, thus reducing the incidence of famine.140 An additional benefit of the increasing intensification of agriculture may be that, by lifting global yields by 1.5 percent per year over the period of a transition to sustainability, approximately one-quarter of the 1.4 billion hectares of cropland can be spared for nature.141
However, although the world has come to depend on these enhancements in food production, it is unclear whether they are sustainable.142 In future decades, the food supply must continue to expand within a range set by basic needs, expanded incomes, and dietary preferences, and at the same time, it must do so with reduced environmental consequences. High-productivity agriculture is built on the use of monocultures, often of genetically identical plants, nourished by irrigation water and fertilizers, protected by pesticides, all delivered by technological and market mechanisms managed and paid for by humans.143 Many such ecosystems are
Page 95
difficult to sustain because of several factors. The low species diversity and high concentration of nutrients provides a setting that favors specialized predators and weed species. Biological regulation by soil organisms is altered, so that decomposition is interrupted and additional nutrients must be supplied. And the application of water and fertilizer during times when growing crops cannot use them leads to waste and pollution.144 Technologies that minimize erosion, water use, salinization, chemical pollution, and other environmental damage are available, but have not been broadly utilized.145
Clearing of Tropical Forests, Regrowing Temperate Zone Forests
Forests currently cover approximately 40 million km2, about three-quarters of their area before the emergence of agriculture.146 They occupy more than twice as much land area as agriculture and harbor two-thirds of all plant species.147 Traditional agro-ecological economies remain both widespread and significant in the tropics; forests are home to millions of people who combine subsistence agriculture on small plots with hunting, gathering, and commercial harvest of materials from the surrounding forest. In temperate zone countries, including parts of China, Russia, and the United States, many forests have regrown during the 20th century, both through deliberate replanting and as agricultural lands have become uneconomical to farm. However, these increases are more than offset, in terms of area cleared or wood cut, by deforestation in tropical countries and land clearing in response to the prices of land for nonforest uses.148
Forest land is cleared for many reasons—for timber, during mining, and to make land available for agriculture. Data on rates of deforestation are sometimes controversial because of the difficulties in obtaining data in many regions of the world, but the estimated gross global deforestation rate is roughly 100,000 km2 per year, yielding 5 billion m3 of wood and fuel.149 Forest soils and standing timber are major storehouses of carbon, and the steady removal of carbon dioxide from the atmosphere by long-lived forest plants is a substantial counterweight to the burning of fossil fuels.150 Forests also provide countless other goods and services; some of these goods, like cacao, play important roles in world markets, while others, including watershed services and medicinals, are valued only by localized human populations. If the rainforests were, for example, an extremely rich and valuable source of pharmaceutical precursor opportunities as many believe, their preservation should be assured by market forces which would not allow their destruction. Unfortunately, to date, they have been only occasionally such a resource.151 Thus, while the management of forests for specific goods or services ranges from tightly regulated in some instances to uncontrolled in others, it is evident that
Page 96
managing for sustainable, multiple-purpose use of forestlands remains elusive.152
For a Sustainable Future
Over the past 50 years humans have altered the earth's lands substantially. To the benefit of our species, agricultural output has been raised dramatically and the regrowth of cleared forests has dominated landscapes in some regions. Much of the increased agricultural output takes place on existing cropland through intensification of production, thus releasing more marginal land for forest and grassland regrowth and reducing further land conversion. But these gains must be seen against the risks and losses of the past half-century. Decreases in tropical forest area and the intensification of agriculture both result in stresses on biodiversity and on ecological systems. Some of these stresses—for example the loss of soil organic matter and of pollinator species, and the changes in biogeochemical and hydrological cycles—are not visible to the casual observer, but their long-term consequences for life support systems warn that a sustainability transition is likely to require wide-ranging shifts in the values ascribed to land and the way people manage its living resources.
Species and Ecosystems153
Decreasing Diversity, Increasing Invasions
In the geologic record, paleontologists have found five mass extinction events, each of which drastically reduced the number of species on earth. Each time, enough life forms survived to repopulate the earth's waters and lands. The impact of human activities on the planet has now accelerated the loss of species and ecosystems to a level comparable to a sixth mass extinction.154 This loss of species diversity is the first driven by a living species.
Rates of species extinction have been estimated to be 100 to 1,000 times as high as before large-scale human dominance of ecosystems.155 Today, 11 percent of birds, 18 percent of mammals, 5 percent of fish, and 8 percent of plant species are threatened by extinction.156 These rates of loss are driven primarily by the alteration of natural habitats. In a given region, the loss of species can be much higher than the proportional loss of land area if habitats are fragmented by roads or other human clearings that isolate patches of unconverted land. Depletion of species in these remaining patches can be delayed, but is still inevitable in the absence of human intervention.
In addition to causing extinctions, human activities also introduce
Page 97
species into ecosystems in which they have not been present. In some situations, these so-called exotic species proliferate, and the introduction of a new species can transform the ecological relationships of habitats and further stress endangered species. For example, an estimated 20 percent of the world's endangered land vertebrates are threatened by invading exotic species.157 Biological invasions of this kind are usually inadvertent, but their frequency can be high. Introduction of exotic aquatic species by human action, often accidentally, such as transporting a species to a distant location in the ballast water of ships, has affected the species composition of heavily traveled coastal areas and bays.158 For example, in San Francisco Bay, California, an average of one new species has been introduced every 36 weeks since 1850, a rate rising to every 12 weeks over the past decade.159 As a result, the life-forms visible to humans in that bay are predominantly nonnative.
Efforts to prevent or control the transfer of exotic species across marine ecosystems are rudimentary, although there has been some progress since the problem came to light more than a decade ago.160 Such accelerating rates of depletion and change will not continue for long: habitats are finite and the loss of species is irreversible. Efforts to slow rates of depletion and change require recognition of the value of the system or what is lost when replaced by exotics, whether in terms of provision of resources and services or on aesthetic or ethical grounds, as well as recognition of the potential economic and environmental costs of invasive species. Yet the value placed on species and ecosystems has been historically uneven. A very small suite of edible and useful species has been valued, conserved, and propagated by humans. These number in the thousands out of tens of millions of species. The far larger ecological assemblages within which these well-known, valuable species live have been neither understood nor managed.
In a small number of cases, endangered species have recovered when protected by human efforts. For example, the bald eagle and marine mammals in North America have rapidly rebuilt their numbers and many populations of marine mammals worldwide are recovering. These recoveries have taken place under conditions where habitats required by the species were either intact or readily protected and where there the public will to preserve or conserve them was strong. Such circumstances do not currently apply to most regions of the world where species are threatened.
Losses of Ecosystems and Ecosystem Services
Just as land conversions and land degradation can lead to losses of species, these trends affecting species can result in degradation or loss of ecosystems and ecosystem services. On a global basis, freshwater, coral
Page 98
reef, and forest ecosystems (the latter just discussed under "Land" above) have suffered enormous assault from human activities.
Covering less than 1 percent of the earth's surface, freshwater ecosystems have lost the largest proportion of species and habitat when compared with other ecosystems on land or with the oceans.161 Increasing trends of overfishing, dam building, river development, and contamination, as human activities expand, will continue to place greater threats on freshwater ecosystems.162 Many estuaries and bays have deteriorated because of activities associated with land development as well as fishing pressure, with resulting declines in ecosystem services. For example, the depletion of the oyster population in Chesapeake Bay through over-exploitation has had a profound effect on the Bay—the oysters once filtered a volume of water equal to that of the entire bay about once a week; they now filter that volume in about one year's time. This circumstance has adversely affected the water quality of the estuary and has impacted many species that live in it, including those consumed by humans.163 Similar human development along coasts, together with associated pollution from agriculture and other land-based sources and harmful fishing practices, has caused 58 percent of the world's coral reefs to be in jeopardy of loss, changes in species composition, or other major ecosystem effects.164 These losses challenge the livelihood of local communities that depend on the reef for food, tourism, and protection against damaging storms. For global forests, expanding populations, together with the increasing need for fuelwood and land for agriculture, have resulted in a net loss of some 180 million hectares between 1980 and 1995. Despite reforestation efforts, the rates of deforestation remain high in many areas of the world.
The decrease and decline of freshwater ecosystems, coral reefs, and forests represents incalculable losses of ecological services, including the recycling of nutrients, water, and wastes; the mitigation of climate and temperature extremes; the management of watersheds; and the support of local communities and cultures.165
For a Sustainable Future
Without active efforts to conserve biodiversity, pinpoint the vectors of and control bioinvasions, and protect natural ecosystems, the trends of increasing loss of species, ecosystems, and ecosystem services will continue and threaten both the long-term stability of ecosystems and the quality of life for humans that depend on those systems for their livelihood. For a sustainable future, efforts will be needed to strengthen the barriers to the free flow of species given growing global trading, to avoid intentional introductions of exotics, to protect and preserve ecosystems as
Page 99
well as endangered or threatened species, to improve mechanisms and information systems for detecting changes and assessing threats, and to promote science for conservation.
Though people have been motivated by aesthetic and cultural considerations to preserve special natural places for millennia, the scientific understanding of conservation biology has taken clear form only in the past decade and a half.166 As these two currents of human activity converge, there has been growing awareness of the need to conserve ecosystem processes. It is therefore necessary to work at the scale of whole landscapes, with explicit attention both to the preservation of critical ecosystems and to the interactions between human activities and the managed and unmanaged ecosystems among them.167 An open question for a transition toward sustainability is whether a reformulated idea of conservation of this kind will prove workable in enough places to salvage the biological richness of the planet. Moreover, the ability to assess and monitor the well-being of the earth's living resources and the services they provide is far from proven, yet efforts in those areas will be essential to understand the roles of species and ecosystems for a sustainable future.
Disease Organisms and Vectors168
Emerging and Reemerging Diseases
The 1980s and 1990s have seen the emergence of 30 new diseases,169 the resurgence of "old" diseases (e.g., tuberculosis), and the redistribution of old diseases on a global scale (e.g., cholera). These trends are in large part related to human activities associated with land use, especially agricultural practices; water storage and use (see Fresh Water section for a discussion of cholera), including irrigation; and urbanization. The intensification of agricultural production has not only increased crop yields, but the related practices of irrigation, land conversion, and habitat disturbance have also increased the risk of infectious diseases such as malaria and schistosomiasis. Some 30 diseases have been linked to irrigation practices (e.g., malaria and Japanese encephalitis with Asian paddy-rice agriculture, mosquito-borne diseases with farming in Central and South America). 170 The incidence of schistosomiasis is believed to have risen over the last 50 years because of the expansion in irrigation systems in hot climates. 171 A tripling of the prevalence of schistosomiasis in Ghana in the late 1950s and early 1960s is believed to be related to the construction of agricultural impoundments which provide habitat for the intermediate host organism.172
Forest land conversions have been associated with higher incidences of malaria and leishmaniasis, through habitat creation conducive to tick
Page 100
and other insect vector breeding. The forest fringes are places where contact between disease organisms and human populations are most efficient in disease transmission.173 Rising surface temperatures associated with deforestation in Africa are believed to be responsible for accelerating the life cycle of the mosquitoes.174
Although commonly believed to be a disease of the past, nearly 3 million people died from tuberculosis in 1995, an indication of the continuing influence of the disease with increasing poverty and homelessness in urban areas, and the importance of multidrug resistance.175 With an apparent leveling off in 1996, the TB epidemic is expected to continue to pose human health problems for developing countries.176
In addition to infectious diseases, a series of new diseases of chemical origin have emerged worldwide in recent decades. There have been dramatic episodes of such disease, for example, the disaster at Bhopal where several thousand persons were killed by acute exposure to the pesticide intermediate toluene diisocyanate (TDI). Also, there are chronic lower level exposures of populations to chemical toxins such as organic mercury, which has the power to damage the nervous system; benzene, which causes cancer; and polychlorinated biphenyls (PCBs), which can impair infant development. New diseases of chemical origin are often first seen in populations occupationally exposed to toxic chemicals, inasmuch as exposures in these groups are typically heavier than in the general population and occur earlier than in the population at large.
For a Sustainable Future
The emergence and reemergence of infectious diseases have important implications for sustainability, especially with expanding populations in areas where diseases are expanding. There will be an enormous challenge to containing the spread of disease while transportation and trading systems grow and while human populations grow and expand into new ecological settings, thereby establishing contact with previously isolated microbes and other infectious agents. Clearly, better systems of surveillance and recognition of emerging diseases are needed, coupled with integrated modeling and the use of geographically based data systems, and also measures for intervention (vaccine and drug development, vector control, and education) to manage future outbreaks.177 These approaches will enable the medical community to take more anticipatory approaches and help optimize preventive strategies.178 Also, better management of the interactions between humans and the environment, especially changes in agricultural practices and water management, will be needed to ensure a sustainable future.
Page 101
Conclusions
Based on our analysis of persistent trends and transitions, the Board concludes that certain current trends of population and habitation, wealth and consumption, technology and work, connectedness and diversity, and environmental change are likely to persist well into the coming century and could significantly undermine the prospects for sustainability. If they do persist, many human needs will not be met, life support systems will be dangerously degraded, and the numbers of hungry and poor will increase. Some of these current trends present significant opportunities for advancing a transition toward sustainability, as well as threats to that transition. All, however, bear watching. Among social trends the Board reviewed that may merit particular attention in efforts to navigate a transition to sustainability are expanding urbanization, growing disparities of wealth, wasteful consumption, increasing connectedness, and shifts in the distribution of power. Environmental trends of special concern include the buildup of long-lived greenhouse gases in the atmosphere and associated climate changes, the decline of valued marine fisheries, increasing regional shortfalls in the quality and quantity of fresh water, expanding tropical deforestation, continuing losses of species, ecosystems, and their services, the emergence and reemergence of serious diseases, and more generally, the increasing human dominance of natural systems.
Even the most alarming current trends, however, may experience transitions that enhance the prospects for sustainability. Trends are rarely constant over time. Breaks or inflections in the long-term trends mark periods of transition. Transitions relevant to the prospects for sustainability are already underway to varying degrees in specific places and regions around the globe: the demographic transition from high to low birth and death rates; the health transition from early death by infectious diseases to late death by cancer, heart disease, and stroke; the economic transition from state to market control; the civil society transition from single-party, military, or state-run institutions to multiparty politics and a rich mix of governmental and nongovernmental institutions. Environmentally, some significant positive transitions have occurred in specific regions. These include shifts from increasing to decreasing rates of emissions for specific pollutants, from deforestation to reforestation, and from shrinking to expanding ranges for certain endangered species.
Individual, local trend reversals such as these clearly do not make a sustainability transition. But they do show that efforts to catalyze or accelerate relevant shifts can have significant implications for meeting human needs in ways that sustain the life support systems of the planet.
Page 102
References and Bibliography
Adelman, I., and S. Robinson. 1989. Income distribution and development. In Handbook of development economics, vol. 2, ed. H. Chenery and T. N. Srinivasan, 949–103. Amsterdam: North Holland.
API (American Petroleum Institute). 1998. How much we pay for gasoline. API Publication No. R26903, 1997 Annual Review.
Anderson, C. 1991. ''Cholera epidemic traced to risk miscalculation." Nature, Vol. 354, p. 255.
Anderson, J.L., W.H. Brune, S.A. Lloyd, W.L. Starr, M. Lowenstein, and J.R. Podolske. 1989. Kinetics of ozone destruction by CIO and BrO within the Antarctic vortex: an analysis based on in-situ ER-2 data. Journal of Geophysical Research 94: 11480.
Arrow, K., B. Bolin, R. Costanza, P. Dasgupta, C. Folke, C.S. Holling, B.O. Jansson, S. Levin, K.G. Maeler, C. Perrings, and D. Dimentel. 1995. Economic growth, carrying capacity, and the environment. Science 268, no. 5210: 520–521.
Ausubel, J.H., and R. Herman eds. 1988. Cities and their vital systems: Infrastructure past, present, and future. Washington, D.C.: National Academy Press.
Ausubel, J.H. 1996a. Can technology spare the earth? American Scientist 84: 166.
Ausubel, J.H. 1996b. The liberation of the environment. Deadalus 125, no. 3: 1–17.
Ausubel, J.H., and A. Grübler. 1995. Working less and living longer: Long-term trends in working time and time budgets. Technological Forecasting and Social Change 50, no. 3: 113–131.
Bacha, E. L. 1978. The Kuznets curve and beyond: Growth and Change in Inequalities. In Economic growth and resources vol. 1, ed. E. Malinvaud, 52–81. New York: St. Martins Press.
Barbault, R., and S.D. Sastrapradja. 1995. Generation, maintenance and loss of biodiversity. In Global biodiversity assessment, ed. V. H. Heywood. Published for the United Nations Environment Programme. New York: Cambridge University Press.
Bartone, Carl, Janis Bernstein, Josef Leitman, Jochen Eigen. 1994. Toward Environmental Strategies for Cities: Policy Considerations for Urban Environmental management in Developing Countries. Urban Management Programme Series 18. Washington, D.C.: The World Bank.
Baumol, W.J., R.B. Nelson, and E.N. Wolff, eds. 1994. Convergence and productivity: Cross-national studies and historical evidence. Oxford: Oxford University Press.
Beckmann, M.J. 1988. An economic model of urban growth. in Cities and their Vital Systems: Infrastructure Past, Present, and Future., eds. J. H. Ausubel and R. Herman. Washington, D.C.: National Academy Press.
Benedick, Richard Elliot. 1991. Ozone diplomacy: New directions in safeguarding the planet. Cambridge, MA: Harvard University Press.
BLS (Bureau of Labor Statistics). 1998. Unpublished data from the Current population survey. Washington, D.C.: BLS.
———. 1999. BLS Current Population Survey. Washington, D.C.: BLS.
Bongaarts, J. 1994. Population policy options in the developing world. Science 263: 771–776.
Bongaarts, J., and J. Bruce. 1997. What can be done to address population growth? Unpublished background paper for High hopes: The United States, global population and our common future. Washington, D.C.: Resources for the Future.
Bos, E., M.T. Vu, E. Masiah, and R.A. Bulatao. 1994. World Population Projections 1994–95 Edition. Baltimore: Johns Hopkins University Press.
Botsford, Louis W., Juan Carlos Castilla, and Charles H. Peterson. 1997. The management of fisheries and marine ecosystems. Science 277, no. 5325: 509-515.
Page 103
Bouwer, Herman. 1992. Agricultural and municipal use of wastewater. Proceedings of the 16th biennial conference of the International Association on Water Pollution Research and Control. Water Science and Technology 26, nos. 7–8: 1583–1591.
Bradley, D. 1994. Institutional capacity to monitor the interactions of agricultural and health change. In Agriculture, environment, and health: Sustainable development in the 21st century, ed. V. W. Ruttan, 308–338. Minneapolis: University of Minnesota Press.
Brandt Report. See Independent Commission on International Development Issues, 1980.
Brown, L.R., Kane, H. and Roodman, D.M. 1994. Vital signs 1994: The trends that are shaping our future. New York: W. W. Norton and Co.
Brown, L.R., M. Renner, C. Flavin. 1998. Vital signs: The environmental trends that are shaping our future. New York: W.W. Norton and Co.
Brundtland Report. See World Commission on Environment and Development, 1987.
Bruno, Michael, Martin Ravallion, and Lyn Squire. 1995. Equity and growth in developing countries: Old and new perspectives in the policy issues. Prepared for the IMF Conference on Income Distribution and Sustainable Growth, June 1–2, 1995. Washington, D.C.: The World Bank.
Burke, Lauretta, et al. 1998. Reefs at Risk: A Map-Based Indicator of Potential Threats to the World's Coral Reefs. World Resources Institute, Washington, D.C.
Carlton, J.T. 1993. Neoextinctions of marine invertebrates. American Zoologist 33, no. 6: 499–409.
Cernea, Michael M. 1993. Urban Environment and Population Relocation. Discussion Paper 152. Washington, D.C.: The World Bank.
Chant, Sylvia H., and Alan Greig. 1996. Gender, urban development, and housing. Publication series for Habitat II, Vol. 2. New York: UNDP.
Chapin, F.S., B.H. Walker, R.J. Hobbs, D.U. Hooper, J.H. Lawton, E. Sala, and D. Tilman. 1997. Biotic control over the functioning of ecosystems. Science 277: 500–505.
Ciais, P., P.P. Tans, M. Trolier, J.W.C. White, and R.J. Francey. 1995. A large northern hemisphere terrestrial CO2 sink as indicated by the 13C/12C Ratio of Atmospheric CO2. Science 269, no. 5227: 1098–1102.
Clark, W.C. 1985. Scales of climate impacts. Climate Change 7: 5–27.
Cohen, A.N., and J.T. Carlton. 1995. Biological study: Nonindigenous aquatic species in a United States estuary: A case study of the biological invasions of the San Francisco Bay and Delta. Washington, D.C.: US Fish and Wildlife Service.
Cohen, Joel E. 1995. How many people can the earth support? New York: W.W. Norton.
Costanza, R., F. Andrade, P. Antunes, M. van den Belt, D. Boersma, D.F. Boesch, F. Catarino, S. Hanna, K. Limburg, B. Low, M. Molitor, J.G. Pereira, S. Rayner, R. Santos, J. Wilson, M. Young. 1998. Principles for sustainable governance of the oceans. Science 281, no. 5374: 198–199.
Councils of the Royal Society of London and the National Academy of Sciences. 1992. Joint statement on population growth, resource consumption and a sustainable world. Washington, D.C.: National Academy of Sciences.
Crutzen, P.J. 1992. On the potential importance of the gas phase reaction CH302 + ClO 
ClOO + CH3O and the heterogeneous reaction HOCl + HCl H2O + Cl2 in 'ozone hole' chemistry. Geophysical Research Letters 19, no. 11: 1113–1116.
Crutzen, P.J., and F. Arnold. 1986. Nitric acid cloud formation in the cold Antarctic stratosphere: A major cause for the springtime "ozone hole." Nature 324: 651–655.
Daily, Gretchen C., ed. 1997. Nature's services: Societal dependence on natural ecosystems. Washington, D.C.: Island Press.
Daily, Gretchen C., Pamela A. Matson, and Peter M. Vitousek. 1997. Ecosystem services supplied by soil. In Nature's services, ed. Daily. Washington, D.C.: Island Press.
Page 104
Dakan, Zuo, and Zhang Peiyuan. 1990. The Huang-Huai-Hai Plain. Chap. 28 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Davey, Kenneth J. 1993. Elements of Urban Management. Urban Management Program Papers No. 11 and 11S. Washington, D.C.: The World Bank.
Deevey, Edward. 1960. The human population. Scientific American 203: 194–204.
DoE/EIA (Department of Energy/Energy Information Administration). 1998a. International energy outlook. DoE/EIA-0484, April 1998. Washington, D.C.: US Government Printing Office.
———. 1998b. Annual energy review. DoE/EIA-0384, July 1998. Washington, D.C.: US Government Printing Office.
———. 1999. World Primary Energy Consumption (Btu), 1988–1997. Available http:// www.eia.doe.gov/emeu/iea/tablee1.html. Last updated 3/25/99.
Dobson, A.P., M.S. Campbell, and J. Bell. 1997. Fatal Synergisms: Interactions between infectious diseases, human population growth and loss of biodiversity. Pages 87–110 in Biodiversity and human health, F. Grifo and J. Rosenthal, eds. Washington, D.C.: Island Press.
Douglas, B.C. 1995. Global sea level change: Determination and interpretation. Reviews of Geophysics 33: 1425–1432.
Dunlap, Riley E. 1997. International opinion at the century's end: public attitudes toward environmental issues. In Environmental policy: Transnational issues and national trends, eds. L.K. Caldwell and R.V. Bartlett, 201-224. Westport, CT: Quorum Books.
Ecological Society of America, Committee on the Scientific Basis for Ecosystem Management. 1996. The report of the Ecological Society of America Committee on the scientific basis for ecosystem management. Washington, D.C.: The Ecological Society of America.
Farman, J.C., B.G. Gardiner, and J.D. Shanklin. 1985. Large losses of total ozone in Antarctica reveal seasonal chlorine oxide-nitrogen oxide interaction. Nature 315, no. 6016: 207–210.
Farvacque-Vitkovic, Catherine, and Lucien Goldin. 1998. The Future of African Cities: Challenges and Priorities in Urban Development. Washington, D.C.: The World Bank.
FAO (United Nations Food and Agriculture Organization). 1997. The state of world fisheries and aquaculture 1996. Rome: FAO.
Freeman, C., and L. Soete. 1987. Technical change and full employment. London: Pinter.
Friedenburg, L.K. 1997. Physical effects of habitat fragmentation. In Conservation Biology, 2d ed., eds. P.L. Fiedler and P.M. Kareiva, 66–79. New York: Chapman and Hall.
Frosch, R. 1994. Industrial ecology: Minimizing the impact of industrial waste. Physics Today 47, no. 11: 63–68.
Fox, William F. 1994. Strategic Options for Urban Infrastructure Management. Urban Management Programme Paper 17. Washington, D.C.: The World Bank.
Gell-Mann, M. 1994. The quark and the jaguar: Adventures in the simple and complex. New York: W. H. Freeman.
Gleick, Peter H. 1998. The world's water: The biennial report on freshwater resources. Washington, D.C.: Island Press.
Grossman, Gene M. and Alan B. Krueger. 1991. Environmental impacts of a North American free trade agreement. Discussion paper 158, November. Princeton, NJ: Woodrow Wilson School, Princeton University.
———. 1995. Economic growth and the environment. Quarterly Journal of Economics 110, no. 2: 353–377.
Grübler, A. 1998. Technology and global change. Cambridge, UK: Cambridge University Press.
Grübler, A., and Nowotny, H. 1990. Towards the fifth Kondratiev upswing: Elements of an emerging new growth phase and possible development trajectories. International Journal of Technology Management 5, no. 4: 431–471.
Page 105
Hayami, Yujiro, and V.W. Ruttan. 1985. Agricultural development: An international perspective. Baltimore: Johns Hopkins University Press. 73–93, 178–187, 264–298.
Hooper, D.U. and P.M. Vitousek. 1997. The effects of plant composition and diversity on ecosystem processes. Science 277: 1302–1305.
Hughes, Thomas P. 1998. Rescuing Prometheus. New York: Pantheon Books.
Husain, L., V.A. Dutkiewicz, and M. Das. 1998. Evidence for decrease in atmospheric sulfur burden in the Eastern United States caused by reduction in SO2 emissions. Geophysical Res. Letters 25, no. 7: 967–970.
IOM (Institute of Medecine). 1992. Emerging infections: Microbial threats to health in the United States. J. Lederberg, R.E. Shope, S.C. Oaks, Jr., eds. Washington, D.C.: National Academy Press.
IPCC (Intergovernmental Panel on Climate Change). 1996. Climate change 1995: The science of climate change. Contribution of Working Group I to the Second Assessment Report of the Intergovernmental Panel on Climate Change. J.T. Houghton, L.G. Meira Filho, B.A. Callander, N. Harris, A. Kattenberg, and K. Maskell, eds. Cambridge, UK: Cambridge University Press.
IUCN (The World Conservation Union). 1996. IUCN Red List of Threatened Animals. Gland, Switzerland: IUCN.
Jickells, Timothy D., Roy Carpenter, and Peter S. Liss. 1990. Marine environment. Chap. 18 in Turner et al. 1990b.
Jodha, Narpat S. 1986. Common property resources and rural poor in dry regions of India. Economic and Political Weekly XXI, no. 27: 1169–81.
Jodha, Narpat S. 1987. A case study of the degradation of common property resources in India. In Piers Blaikie and Harold Brookfield, eds. Land Degradation and Society. London: Nethuen. pp. 196–207.
Kahrl, W.L. 1982. Water and Power: The Conflict Over Los Angeles' Water Supply in the Owens Valley. Berkeley: University of California Press.
Kasperson, Jeanne X., Roger E. Kasperson, B.L. Turner II, eds. 1995. Regions at Risk: Comparisons of threatened environments. Tokyo: United Nations University Press.
Kasperson, J.X., R.E. Kasperson, and B.L. Turner, II, eds. 1995. Regions at risk: Comparisons of threatened environments. Tokyo: United Nations University.
Kates, R.W. 1994. Sustaining life on earth. Scientific American 271, no. 4: 114–122.
Kates, Robert W. 1997. Population, technology, and the human environment: A thread through time. Daedalus 125, no. 3: 1–29. Also published in: Jesse H. Ausubel and H. Dale Langford eds. Technological Trajectories and the Human Environment, Washington, D.C.: National Academy Press. 33–55.
Kates, R.W. and W.C. Clark. 1996. Environmental surprise: Expecting the unexpected? Environment 38, no. 2: 6–11, 28–35.
Kates, R.W., B.L. Turner, and W.C. Clark 1990. The great transformation. Chap. 1 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Kempton, Willett, James S. Boster, and Jennifer A. Hartley. 1995. Environmental values in American culture. Cambridge, MA: MIT Press.
Khalil, M.A.K., and R.A. Rasmussen. 1994. Global decrease of atmospheric carbon monoxide concentration. Nature 370, no. 6491: 639–641.
Khush, G.S. 1995. Modern varieties and their real contributions to food supplies and equity. GeoJournal 35, no. 3: 275–284.
Kingsley, Thomas. 1994. Managing Urban Environmental Quality in Asia. World Bank Technical Paper 220. Washington, D.C.: The World Bank.
Knodel, J., and van de Walle, E. 1976. Lessons from the past: Policy implications of historical fertility studies. Population and Development Review 5:217–245.
Page 106
Laurance, W.F., S.G. Laurance, L.V. Ferreira, J.M. Rankin-deMerona, C. Gascon, and T.E. Lovejoy. 1997. Biomass collapse in Amazonian forest fragments. Science 278, no. 5340: 1117–1118.
Lawton, J.H. and R.M. May, eds. 1995. Extinction rates. Oxford, UK: Oxford University Press.
Lee, K.N. 1993. Compass and gyroscope: Integrating science and politics for the environment. Washington, D.C.: Island Press.
Lee, S.H., H. Akimoto, H. Nakane, S. Kurnosenko, and Y. Kinjo. 1998. Lower tropospheric ozone trend observed in 1989–1998 at Okinawa, Japan. Geophys. Res. Letters 25, no. 10: 1637–1640.
Lindsay, S.W., and M.H. Birley. 1996. Climate change and malaria transmission. Annals of Tropical Medicine and Parasitology 90, no. 6: 573–588.
Logan, J.A. 1994. Trends in the vertical distribution of ozone: An analysis of ozone sonde data. Journal of Geophysical Research 99, no. 25: 553–525, 585.
Lovejoy, T.E. 1997. Biodiversity: What is it? In Biodiversity II, eds. M.L. Reaka-Kudla, D.E. Wilson, and E.O. Wilson, 7–14. Washington, D.C.: National Academy Press.
L'vovich, Mark I., and Gilbert F. White. 1990. Use and transformation of terrestrial water systems." Chapter 14 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
MacDonald, I.A., L.L. Loope, M.B. Usher, and O. Hamann. 1989. Wildlife conservation and the invasion of nature reserves by introduced species: a global perspective. In Biological Invasions: A Global Perspective, eds. J.A. Drake, H.A. Mooney, F. di Castri, R.H. Groves, F.J. Kruger, M. Rejmánek, and M. Williamson. Chichester: John Wiley and Sons.
Maddison, Angus. 1995. Monitoring the world economy, 1820–1992. Paris: Development Centre of the Organisation for Economic Co-Operation and Development.
Margat, J. 1996. Comprehensive assessment of the freshwater resources of the world: Groundwater component. Contribution to Chapter 2 of the Comprehensive Global Freshwater Assessment, United Nations.
Mahlman, J.D. 1997. Uncertainties in projections of human-caused climate warming. Science 278:1416–17.
Malakoff, D. 1997. Extinction on the high seas. Science 275, no. 5325: 486–488.
Marty, Martin E. and R. Scott Appleby, eds. 1991. The fundamentalism project: A study conducted by the American Academy of Arts and Sciences. Chicago: University of Chicago Press.
Mathews, J. 1997. Power shift. Foreign Affairs 76, no. 1: 50–66.
Matson, P.A., W.J. Parton, A.G. Power, and M.J. Swift. 1997. Agricultural intensification and ecosystem properties. Science 277: 504–509.
McAllister, Don E., Andrew L. Hamilton, and Brian Harvey. 1997. Global freshwater biodiversity: Striving for the integrity of freshwater ecosystems. Ottawa: Ocean Voice International.
McCrabb, G.J., K.T. Berger, T. Magner, C. May, and R.A. Hunter. 1997. Inhibiting methane production in Brahman cattle by dietary supplementation with a novel compound and the effects on growth. Australian Journal of Agricultural Research 48: 323–9.
McGrattan, E.R., and R. Rogerson. Changes in hours worked since 1950. Federal Reserve Bank of Minneapolis Quarterly Review 22, no. 1: 2–19.
Montzka, S.A., J.H. Butler, R.C. Myers, T.M. Thompson, T.H. Swanson, A.D. Clarke, L.T. Lock, and J.W. Elkins. 1996. Decline in the tropospheric abundance of halogen from halocarbons: Implications for stratospheric ozone depletion. Science 272, no. 5266: 1318–1322.
Page 107
NAE (National Academy of Engineering). 1994. The greening of industrial ecosystems. B. Allenby and D. Richards, eds. Washington, D.C.: National Academy Press.
———. 1997. Technological trajectories and the human environment. J.H. Ausubel and H.D. Langford, eds. Washington, D.C.: National Academy Press.
NMFS (National Marine Fisheries Service). 1996. Magnuson-Stevens Fishery Conservation and Management Act, as amended through October 11, 1996. Technical Memorandum NMFS-F/SPO-23, December 1996. Washington, D.C.: NOAA.
———. 1997. Report to Congress: Status of the fisheries of the United States, September 1997. Washington, D.C.: National Oceanic and Atmospheric Administration (NOAA).
NRC (National Research Council). 1988. Biodiversity. E.O. Wilson, ed. Washington, D.C.: National Academy Press.
———. 1986. Acid deposition: Long-term trends. Committee on Monitoring and Assessment of Trends in Acid Deposition. Washington, D.C.: National Academy Press.
———. 1991. Toward sustainability: A plan for collaborative research on agriculture and natural resource management. Panel for Collaborative Research Support for AID's Sustainable Agriculture and Natural Resource Management. Washington, D.C.: National Academy Press.
———. 1994. Environmental science in the coastal zone: Issues for further research. Washington, D.C.: National Academy Press.
———. 1995a. Science, policy, and the coast: Improving decision making. Committee on Science and Policy for the Coastal Ocean. Washington, D.C.: National Academy Press.
———. 1995b. Understanding marine biodiversity. Committee on Biological Diversity in Marine Systems. Washington, D.C.: National Academy Press.
———. 1996. Upstream: Salmon and society in the Pacific Northwest. Committee on the Protection and Management of Pacific Northwest Anadromous Salmonids. Washington, D.C.: National Academy Press.
———. 1997. Environmentally significant consumption: Research directions. Paul C. Stern, Thomas Dietz, Vernon W. Ruttan, Robert H. Socolow, and James L. Sweeney, eds. Committee on the Human Dimensions of Global Change. Washington, D.C.: National Academy Press.
———. 1998a. Issues in potable reuse: The viability of augmenting drinking water supplies with reclaimed water. Committee to Evaluate the Viability of Augmenting Potable Water Supplies with Reclaimed Water. Washington, D.C.: National Academy Press.
———. 1998b. Opportunities in ocean sciences: Challenges on the horizon. Ocean Studies Board. Washington, D.C.: National Academy Press.
———. 1999a. Sustaining marine fisheries. Committee on Ecosystem Management for Sustainable Marine Fisheries. Washington, D.C.: National Academy Press.
———. 1999b. Water for the future: The West Bank and Gaza Strip, Israel, and Jordan. Committee on Sustainable Water Supplies in the Middle East; Israel Academy of Sciences and Humanities; Palestine Academy for Science and Technology; Royal Scientific Society, Jordan; and the US National Academy of Sciences. Washington, D.C.: National Academy Press.
Nakicenovic, N. 1997. Freeing energy from carbon. In Technological trajectories and the human environment, eds. J.H. Ausubel and H.D. Langford. Washington, D.C.: National Academy Press.
Naylor, R.L. 1996. Energy and resource constraints on intensive agricultural production. Annual Review of Energy and Environment 21: 99–123.
Newell, R.I.E. 1988. Ecological changes in the Chesapeake Bay: Are they the results of over-harvesting the American oyster Crassostrea virginica? In Understanding the estuary: Advances in Chesapeake Bay research. Proceedings of a conference, 29–31 March 1988, Baltimore, MD. Solomons, MD: Chesapeake Research Consortium.
Page 108
Noble, Ian R., and Rodolfo Dirzo. 1997. Forests and human-dominated ecosystems. Science 277: 522–525.
Novelli, P., K. Masarie, P. Tans, and P. Lang. 1994. Recent changes in atmospheric carbon monoxide. Science 263: 1587–1590.
NUA. 1998. NUA Internet Surverys. Available http://www.nua.ie/surveys/how_many_online/index.html.
Ostrom, Elinor. 1990. Governing the commons. The evolution of institutions for collective action. Cambridge, UK: Cambridge University Press.
PCAST (President's Committee of Advisers on Science and Technology). 1997. Federal energy R&D for the challenges of the twenty-first century. Report of the Energy R&D Panel of PCAST. Washington, D.C.: PCAST.
Patz, J.A., P.R. Epstein, T.A. Burke, and J.M. Balbus. 1996. Global climate change and emerging infectious diseases. Journal of the American Medical Association 275, no. 3: 217–23.
Pennisi, E. 1997. Brighter prospects for the world's coral reefs? Science 275, no. 5325: 491–493.
Peterson, T.C., and R.S. Vose. 1997. An overview of the Global Historical Climatology Network temperature data base. Bulletin of the American Meteorological Society 78: 2837–2849.
Pinstrup-Anderson, P., R. Pandya-Lorch, and M.W. Rosegrant. 1997. The world food situation: Recent developments, emerging issues, and long-term prospects. Washington, D.C.: International Food Policy Research Institute.
Population Reference Bureau. 1997. 1997 World population data sheet of the Population Reference Bureau. Washington, D.C.: Population Reference Bureau.
Postel, Sandra, Gretchen C. Daily, and Paul Ehrlich. 1996. Human appropriation of renewable fresh water. Science 271, no. 5250: 785–788.
Postel, Sandra. 1997. Last oasis: Facing water scarcity. New York: W.W. Norton & Company.
Putnam, R. 1995. Tuning in, tuning out: The strange disappearance of social capital in America. Political Science and Politics 28, no. 4: 664–684.
Rakesh, Mohan. 1994. Understanding the Developing Metropolis. New York: Oxford University Press. Published for the World Bank.
Raskin, P. 1997. Water futures: Assessment of long-range patterns and problems. Background paper for UN/SEI Comprehensive Assessment of the Freshwater Resources of the World. Stockholm: Stockholm Environment Institute.
Raskin, P., M. Chadwick, T. Jackson, and G. Leach. 1995. The transition toward sustainability: Beyond conventional development. Boston: Stockholm Environmental Institute.
Raskin, P., H. Hansen, and R. Margolis. 1995. Water and sustainability: A global outlook. POLESTAR Series report no. 4. Stockholm: Stockholm Environment Institute.
Raskin, P., and R. Margolis. 1995. Global energy in the 21st century: Patterns, projections, and problems. POLESTAR Series report no. 3. Stockholm: Stockholm Environment Institute.
Raskin, P., G. Gallopin, P. Gutman, A. Hammond, and R. Swart. 1998. Bending the curve: Toward global sustainability. A report of the Global Scenario Group. PoleStar Series Report no. 8. Boston: Stockholm Environment Institute.
Rasmussen, Paul E., Keith W.T. Goulding, James R. Brown, Peter R. Grace, H. Henry Janzen, Martin Körschens. 1998. Long-eterm agroecosystem experiments: Assessing agricultral sustainability and global change. Science 282:893–896.
Reaka-Kudla, M.L. 1997. The global biodiversity of coral reefs: A comparison with rain forests. In Biodiversity II: Understanding and Protecting Our Biological Resources, eds. Marjorie L. Reaka-Kudla, Don E. Wilson, and Edward O. Wilson. Washington, D.C.: Joseph Henry Press.
Page 109
Richards, John F. 1990. Land transformation. Chap. 10 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Rifkin, J. 1995. The end of work: The decline of the global labor force and the dawn of the post-market era. New York: G.P. Putnam.
Rogers, Peter P., Kazi F. Jalal, Bindu N. Lohani, Gene M. Owens, Chang-Ching Yu, Christian M. Dufournaud, and Jun Bi. 1997. Measuring environmental quality in Asia. Division of Engineering and Applied Sciences, Harvard University, Asian Development Bank. Cambridge, MA: Harvard University Press.
Rostow, W.W. 1961. The stages of economic growth: A non-Communist manifesto. Cambridge, UK: Cambridge University Press.
Rowland, F.S. and M. Molina. 1975. Chloromethane in the environment. Reviews of Geophysics and Space Physics 13: 1–35.
Rozanov, Boris G., Viktor Targulian, and D.S. Orlov. 1990. Soils. Chap. 12 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Runge, F. 1997. Globalization and sustainability: The machine in the garden. Unpublished paper prepared for the BSD.
Schmidt, K.F., and D. Malakoff. 1997. 'No-take' zones spark fisheries debate. Science 275, no. 5325: 489–491.
Schneider, S., and Turner, B.L., II. In preparation. Report of the 1994 Aspen Global Change Institute: Summer session II on surprise and global environmental change.
Schor, J. 1991. The overworked American. New York: Basic Books.
Schwarz, Harry E., Jacque Emel, William J. Dickens, Peter Rogers, and John Thompson. 1990. Water quality and flows. Chap. 15 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Sensenbrenner, Julia S. 1994. State enterprises tackle labor reform. China Business Review 21, no. 6.
Serageldin, Ismail, and Michael Cohen. 1995. The Human Face of the Urban Environment: A Report of the Development Community. Environmentally Sustainable Development Proceedings Series Paper No. 5. Washington, D.C.: The World Bank.
Shiklomanov, Igor A. 1993. World fresh water resources. In Water in crisis: A guide to the world's fresh water resources, ed. P.H. Gleick. New York: Oxford University Press.
Simmonds, P.G., S. Seuring, G. Nickless, and R.G. Derwent. 1997. Segregation and interpretation of ozone and carbon monoxide measurements by air mass origin at the TOR station, Mace Head, Ireland from 1987 to 1995. Journal of Atmospheric Chemistry 28: 45–59.
Simpson, R. David, Roger A. Sedjo, and John W. Reid. 1996. Valuing biodiversity for use in pharmaceutical research. Journal of Political Economy 104:163–185,
Solley, W.B., R.R. Pierce, and H.A. Perlman. 1993. Estimated use of water in the United States in 1990. In Trends 1950–1990, 65, Table 31. Washington, D.C.: US Geological Survey circular (1081).
Solomon, S., R.R. Garcia, F.S. Rowland, and D.J. Wobbles. 1986. On the depletion of Antarctic ozone. Nature 321: 755.
Speth, J.G. 1992. The transition to a sustainable society. Proceedings of the National Academy of Sciences 89: 870–872.
Stephens, C. 1996. Healthy cities or unhealthy islands? The health and social implications of urban inequality. Environment and Urbanization 8, no. 2: 9–30.
Page 110
Stern, P., T. Dietz, V. Ruttan, R.H. Socolow, and J.L. Sweeney., eds. 1997. Environmentally significant consumption: Research directions. Committee on the Human Dimensions of Global Change. Washington, D.C.: National Academy Press.
Thompson, Gary D., and Paul N. Wilson. 1994. Ejido reforms in Mexico: Conceptual issues and potential outcomes. Land Economics 70, no. 4: 448–465.
Turner, B.L., R.E. Kasperson, W.B. Meyer, K.M. Dow, D. Golding, J.X. Kasperson, R.C. Mitchell, and S.J. Ratick. 1990a. Two types of global environmental change: Definitional and spatial scale issues in their human dimensions. Global Environmental Change 1: 14–22.
Turner, B.L., W.C. Clark, R.W. Kates, J.F. Richards, J.T. Mathews, and W.B. Meyer. 1990b. The Earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years. Cambridge, UK: Cambridge University Press.
UN (United Nations). 1980. Patterns of urban and rural population growth. New York: UN.
———. 1992. Protection of the quality and supply of freshwater resources: Application of integrated approaches to the development, management and use of water resources. Chapter 18 of Agenda 21. New York: United Nations.
———. 1993. World population prospects: The 1992 revision. New York: United Nations Department for Economic and Social Information and Policy Analysis.
———. 1995a. World urbanization prospects: The 1994 revision. New York: United Nations.
———. 1995b. The challenge of urbanization: The world's largest cities. Department for Economic and Social Information and Policy Analysis. Population Division. New York: United Nations.
———. 1997a. Critical trends: Global change and sustainable development. New York: United Nations Department for Policy Coordination and Sustainable Development.
———. 1997b. Report of the Secretary-General on a comprehensive assessment of the freshwater resources of the world. E/CN.17/1997/9. New York: United Nations.
———. 1998. World population prospects: The 1996 revision. New York: United Nations Population Division.
———. 1999 (forthcoming). World population prospects: The 1998 revision. New York: United Nations Population Division.
UNDP (UN Development Programme). 1992. Human development report 1992. New York: Oxford University Press.
———. 1995. Human development report 1995. New York: Oxford University Press.
———. 1996. Human development report 1996. New York: Oxford University Press.
———. 1998. Human development report 1998. New York: Oxford University Press.
UNCHS (United Nations Centre for Human Settlements). 1996. An urbanizing world: Global report on human settlements 1996. Oxford: Oxford University Press.
UNEP (United Nations Environment Programme). Division of Environment Information and Assessment. 1996. Characterization and assessment of groundwater quality concerns in Asia-Pacific region. Nairobi: UNEP.
Vanderschueren, Franz, Emiel Wegelin and Kadmiel Wekwete. 1996. Policy Programme Options for Urban Poverty Reduction: A Framework for Action at the Municipal Level. Urban Management Program Paper No. 20. Washington, D.C.: The World Bank.
Vitousek, P., P. Ehrlich, A. Ehrlich, and P. Matson. 1986. Human appropriation of the products of photosynthesis. Bioscience 36: 368–373.
Vitousek, P.M., H.A. Mooney, J. Lubchenco, and J.M. Melillo. 1997. Human domination of earth's ecosystems. Science 277: 494–499.
WHO (World Health Organization). 1992. Our planet, our health. Geneva: WHO.
———. 1996a. The world health report 1996: Fighting disease and fostering development. Geneva: World Health Organization.
Page 111
———. 1996b. Groups at risk: WHO report on the Tuberculosis epidemic 1996. Geneva, Switzerland: Global Tuberculosis Programme, WHO.
———. 1996c. Water supply and sanitation sector monitoring report: 1996 (Sector Status as of 1994). Water Supply and Sanitation Collaborative Council and the United Nations Children's Fund. New York: UNICEF.
WRI (World Resources Institute). 1996. World resources 1996–97: A guide to the global environment. A joint publication by the World Resources Institute, the United Nations Environment Programme, the United Nations Development Programme, and the World Bank. New York: Oxford University Press.
———. 1998. World resources 1998–99: A guide to the global environment. A joint publication by the World Resources Institute, the United Nations Environment Programme, the United Nations Development Programme, and the World Bank. New York: Oxford University Press.
Walker, H. Jesse. 1990. The coastal zone. Chapter 16 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Walsh, J. 1991. Preserving the options: Food production and sustainability. Working Papers on Issues of Agriculture. Washington, D.C.: Consultative Group on International Agricultural Research (CGIAR).
Wernick, I. 1996. Consuming Materials: The American way. Technological Forecasting and Social Change 53: 111–122.
Wernick, I. and J. Ausubel. 1995. National materials flow and the environment. Annual Review of Energy and Environment 20: 463–492.
Wernick, I., R. Herman, S. Govind, and J. Ausubel. 1997. Materialization and dematerialization: Measures and trends. In Technological Trajectories and the Human Environment, eds. J. Ausubel and H. Langford, 135–156. Washington, D.C.: National Academy Press.
White, R.M. and R.H. White. 1997. Technological advance and global work patterns. Cosmos Journal 7: 63–67.
Williams, Michael. 1990. Forests. Chap. 11 in The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, eds. Turner et al. Cambridge, UK: Cambridge University Press.
Wilson, Edward O. 1993. The Diversity of Life. Cambridge, MA: Harvard University Press.
Wilson, Mary E. 1994. Disease in evolution: Introduction. In Disease in evolution: Global changes and emergence of infectious diseases. Annals of the New York Academy of Sciences, vol. 740. Eds. Mary E. Wilson, Richard Levins, and Andrew Spielman. New York: New York Academy of Sciences.
World Bank. 1992. World development report 1992: Development and environment. New York: Oxford University Press.
World Bank. 1995. Better Urban Services: Finding the Right Incentives. Washington, D.C.: The World Bank.
World Bank. 1996. Livable Cities for the 21st Century. Washington, D.C.: The World Bank.
World Bank. 1999. World Bank poverty update: Trends in poverty. Washington, D.C.: The World Bank. Available http://www.worldbank.org. Visited 6/4/99.
World Commission on Environment and Development. 1987. Our common future. New York: Oxford University Press. (Brundtland Report)
Zlotnick, Hania. 1998. International migration 1965-1996: An overview. In Population and Development Review 24, no. 3.
Page 112
Endnotes
1 This discussion applies generally to both quantities and rates of change in quantities of interests (e.g., population size and population growth rates). Depending on circumstances, the transitions or breaks of interest may reflect either first or second derivatives for the quantity in question.
2 UN (1997a).
3 Speth (1992).
4 Gell-Mann (1994).
5 UN (1999).
6 Bongaarts (1994); Bongaarts and Bruce (1997).
7 See UN (1994a, 1999).
8 UN (1999).
9 UN (1999).
10 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to trends in urbanization include:
Clean Air and Highway Transportation: Mandates, Challenges, and Research Opportunities. Transportation Research Board. (1997).
Managing Wastewater in Coastal Urban Areas. Committee on Wastewater Management for Coastal Urban Areas. (1993).
Meeting Megacity Challenges: A Role for Innovation and Technology. Committee on Meeting Megacity Challenges. (1999).
Perspectives on Urban Infrastructure. Committee on National Urban Policy. (1984).
Rethinking the Ozone Problem in Urban and Regional Air Pollution. Committee on Tropospheric Ozone Formation and Measurement. (1991).
Rethinking Urban Policy: Urban Development in an Advanced Economy. Committee on National Urban Policy. (1983).
The Costs of Sprawl—Revisited. Transportation Research Board. (1998).
The Role of Transit in Creating Livable Metropolitan Communities. Transportation Research Board. (1997).
Toward Infrastructure Improvement: An Agenda for Research. Committee for an Infrastructure Technology Research Agenda. (1994).
Transit and Urban Form. Transportation Research Board. (1997).
Transit-Focused Development. Transportation Research Board. (1997).
Urban Change and Poverty. Committee on National Urban Policy. (1988).
Urban Policy in a Changing Federal System. Committee on National Urban Policy. (1985).
11 UN (1999).
12 UN (1998).
13 Beckman (1988); WRI (1996), p. 151.
14 WRI (1996).
15 Beckmann (1988).
16 UN (1995).
17 WRI (1996), pp. 8–9; UN (1995).
18 UNDP (1995), pp. 134–35.
19 UNDP (1995), Ch. 1.
20 World Bank (1999).
21 UNDP (1995), Ch. 3.
22 Rostow (1961).
23 Ausubel and Herman (1988).
24 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to wealth and consumption include:
Page 113
Environmentally Significant Consumption: Research Directions. Committee on the Human Dimensions of Global Change. Eds. Paul Stern, Thomas Dietz, Venon Ruttan, Robert Socolow, and James Sweeney. (1997).
Linking Science and Technology to Society's Environmental Goals. National Forum on Science and Technology Goals. (1996).
25 Maddison (1995).
26 UNDP (1996).
27 UNDP (1996), p. 13.
28 Baumol et al. (1994).
29 Bruno et al. (1995).
30 Bacha (1978); Adelman and Robinson (1989)
31 UNDP (1998).
32 NRC (1997).
33 Councils of the Royal Society of London and the National Academy of Sciences (1992). Not all growth in consumption is necessarily resource-depleting, or ''less available for future use," or environmentally damaging in that it "negatively impacts biophysical systems in such a way as to threaten human health, welfare, or other things people value." However, there is no readily accepted methodology for separating out resource-depleting or environmentally damaging consumption from general consumption, or to identify harmful transformations from those that are benign. Increasingly, almost any human-induced transformation turns out to be either resource-depleting or damaging to some valued environmental component, or both. At best, there may be methods of separating consumption into more or less damaging and depleting classes.
34 DoE/EIA (1998a,b, 1999).
35 NAE (1997).
36 Wernick and Ausubel (1995).
37 Wernick (1996).
38 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to technology and work include:
Automotive Fuel Economy: How Far Should We Go? Committee on Fuel Economy of Automobiles and Light Trucks. (1992).
Bridge Builders: African Experiences with Information and Communication Technology. Office of International Affairs. (1996).
Building an Effective Environmental Management Science Program: Final Assessment. Committee on Building an Environmental Management Science Program. (1997).
Building for Tomorrow: Global Enterprise and the U.S. Construction Industry. Committee on the International Construction Industry. (1988).
Clean Production in Rapidly Industrializing Countries: Challenges and Opportunities. National Academy of Engineering (NAE), Office of International Affairs. (1998).
Commercialization of New Materials for a Global Economy. National Materials Advisory Board. (1993).
Corporate Restructuring and Industrial Research and Development. Academy Industry Program. (1990).
Disposal of Industrial and Domestic Wastes: Land and Sea Alternatives. Panel on Land and Sea Alternatives for the Disposal of Industrial and Domestic Wastes. (1984).
Education for the Manufacturing World of the Future. Robert Frosch and Erich Bloch, Symposium on Education for the Manufacturing World of the Future. (1985).
Engineering and the Advancement of Human Welfare: Ten Outstanding Achievements 1964–1989. NAE. (1989).
Engineering Within Ecological Constraints. NAE. Ed. Peter Schulze. (1996).
Page 114
In Situ Bioremediation: When Does it Work? Committee on In Situ Bioremediation. (1993).
Industrial Ecology: US-Japan Perspectives. NAE. Eds. Deanna Richards and Ann Fullerton. (1994).
Information Technologies and Social Transformation. NAE. Eds. Joseph V. Charyk and Bruce Guile. (1985).
Information Technology and the Conduct of Research: The User's View. Panel on Information Technology and the Conduct of Research. (1989).
Integrated Environmental and Economic Accounting. Committee on National Statistics. (1999).
Intrinsic Remediation of Contaminants in Subsurface Environments. Water Science and Technology Board. In progress.
Keeping Pace with Science and Engineering: Case Studies in Environmental Regulation. NAE. (1993).
Linking Science and Technology to Society's Environmental Goals. National Forum on Science and Technology Goals. (1996).
Marshaling Technology for Development: Proceedings of a Symposium. Technology and Development Steering Committee. Eds. Gerald Dineen and Jean-Françoise Rischard. Office of International Affairs. (1995).
Mastering a New Role: Shaping Technology Policy for National Economic Performances. NAE. Committee on Technology Policy Options in a Global Economy. (1993).
Measures of Environmental Performance and Ecosystem Conditions. NAE. Ed. Peter Schulze. (1999).
National Interests in an Age of Global Technology. NAE. Committee on Engineering as an International Enterprise. Eds. Thomas H. Lee and Proctor P. Reids. (1991).
Opportunities in Applied Environmental Research and Development. Committee on Opportunities in Applied Environmental Research and Development. (1991).
Putting Biotechnology to Work: Bioprocess Engineering. Committee on Bioprocess Engineering. (1992).
Realizing the Information Future: The Internet and Beyond. RENAISSANCE Committee. (1994).
Responding to Changes in Sea Level: Engineering Implications. Committee on Engineering Implications of Changes in Relative Mean Sea Level. (1987).
Restoring and Protecting Marine Habitat: The Role of Engineering and Technology. Committee on the Role of Technology in Marine Habitat. (1994).
Review of the Research Program of the Partnership for a New Generation of Vehicles (Phase 4). Standing Committee to Review the Research Program of the Partnership for a New Generation of Vehicles. (1998).
Review of the Research Program of the Partnership for a New Generation of Vehicles, Fifth Report. Board on Energy and Environmental Systems and the Transportation Research Board. (1999).
Technological Trajectories and the Human Environment. NAE. Eds. Jesse H. Ausubel and H. Dale Langford. (1997).
Technology and Environment. NAE. Eds. Jesse H. Ausubel and Hedy E. Sladovich. (1989).
The Ecology of Industry: Sectors and Linkages. NAE. Eds. Deanna Richards and Greg Pearson. (1998).
The Greening of Industrial Ecosystems. NAE. Eds. Braden Allenby and Deanna Richards. (1994).
The Industrial Green Game: Implications for Environmental Design and Management. NAE. Ed. Deanna Richards. (1997).
Page 115
Tracking Toxic Substances at Industrial Facilities: Engineering Mass Balance Versus Materials Accounting. Committee to Evaluate Mass Balance Information for Facilities Handling Toxic Substances. (1990).
39 API (1998).
40 E.g., the experience of the Department of Defense and later NASA in the United States. See Hughes (1998).
41 PCAST (1997); Grübler (1998).
42 Grübler (1998), Fig. 6.17, p. 243.
43 Grübler, , A. (1998), Pages 644–247, Sec. 6.6.4, Table 6.5; NAE (1994).
44 BLS (1998, 1999); McGrattan and Rogerson (1998).
45 Schor (1991).
46 Rifkin (1995); White and White (1997); Freeman and Soete (1987).
47 Brown et al. (1994).
48 Mathews (1997).
49 See International Telecommunications Union Yearbook of Statistics (1999).
50 1988 figures, UNDP (1992); 1995 figures, UNDP (1998).
51 NUA Internet Surveys (1998).
52 Kempton et al. (1995); Dunlap (1997).
53 Zlotnick (1998).
54 WRI (1996).
55 Brown et al. (1998, refugees, p. 105; trends, p. 77).
56 Runge (1997).
57 Rapid transmission of infectious diseases, WRI (1998); biological invasions, Vitousek et al. (1997).
58 Zlotnick (1998).
59 Marty and Appleby (1991).
60 Putnam (1995).
61 Mathews (1997).
62 Jodha (1986); Jodha (1987); Ostrom (1990); Thompson and Wilson (1994).
63 Sensenbrenner (1994).
64 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to rates, scales, and multiple stresses of global change include:
A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change. Panel on Aerosol Radiative Forcing and Climate Change. Ed. John H. Seinfeld. (1996).
A Review of the U.S. Global Change Research Program and NASA's Mission to Planet Earth/Earth Observing System. Committee on Global Change Research. (1995).
China and Global Change: Opportunities for Collaboration. Panel on Global Climate Change Sciences in China. (1992).
Coastal Meteorology: A Review of the State of the Science. Committee on Meteorological Analysis, Prediction and Research. (1992).
Earth Observations From Space: History, Promise, and Reality. (1995).
Effects of Past Global Change on Life. Board on Earth Sciences and Resources. (1995).
Finding the Forest in the Trees: The Challenge of Combining Diverse Environmental Data. Committee for a Pilot Study on DAtabase Interfaces. (1995).
Four-Dimensional Model Assimilation of Data: A Strategy for the Earth System Sciences. Panel on Model-assimilated Data Sets for Atmospheric and Oceanic Research. (1991).
Global Change and Our Common Future: Papers from a Forum. Committee on Global Change. (1989).
Page 116
Global Environmental Change: Research Pathways for the Next Decade. Committee on Global Change Research. (1998).
Global Environmental Change: Understanding the Human Dimensions. Committee on Human Dimensions of Global Change. (1991).
GOALS (Global Ocean-Atmosphere-Land System) for Predicting Seasonal-to-Interannual Climate: A Program of Observation, Modeling, and Analysis. Climate Research Committee. (1994).
Material Fluxes on the Surface of the Earth. Board on Earth Sciences and Resources. (1994).
National Science and Technology Strategies in a Global Context: Report of an International Symposium. Government-University-Industry Research Roundtable. (1998).
Oceanography in the Next Decade: Building New Partnerships. Ocean Studies Board. (1993).
One Earth, One Future: Our Changing Global Environment. Cheryl Silver and Ruth DeFries. (1992).
Opportunities and Priorities in Arctic Geoscience. Committee on Arctic Solid-Earth Geosciences. (1991).
Ozone Depletion, Greenhouse Gases, and Climate Change. Proceedings of a Joint Symposium by the Board on Atmospheric Sciences and Climate and the Committee on Global Change Research. (1989).
Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base. Committee on Science, Engineering, and Public Policy. (1992).
Research Strategies for the USGCRP. Committee on Global Change. (1990).
Research to Protect, Restore, and Manage the Environment. Committee on Environmental Research. (1993).
Review of EPA's Environmental Monitoring and Assessment Program: Overall Evaluation. Committee to Review the EPA's Environmental Monitoring and Assessment Program. (1995).
Science Policy and the Coast: Improving Decision-Making. Committee on Science and Policy for the Coastal Ocean. (1996).
Science Priorities for the Human Dimensions of Global Change. Committee on the Human Dimensions of Global Change. (1994).
Sea-Level Change. Geophysics Study Committee. (1990).
Solar Influences on Global Change. Board on Global Change. (1994).
Solid-Earth Sciences and Society. Committee on the Status and Research Opportunities in the Solid Earth Sciences: A Critical Assessment. (1993).
The Ocean's Role in Global Change: Progress of Major Research Programs. Ocean Studies Board. (1994).
The U.S. Global Change Research Program: An Assessment of FY 1991 Plans. Committee on Global Change. (1990).
Toward an Understanding of Global Change: Initial Priorities for U.S. Contributions to the International Geosphere-Biosphere Program. Committee on Global Change. (1989).
Understanding Risk: Informing Decisions in a Democratic Society. Committee on Risk Characterization. Eds. Paul C. Stern and Harvey V. Fineberg. (1996).
65 Kates et al. (1990).
66 Turner et al. (1990b).
67 Ibid.
68 Vitousek et al. (1986); Postel et al. (1996); Vitousek et al. (1997).
69 Vitousek et al. (1986).
70 Postel et al. (1996).
71 Cohen (1995), Ch. 14.
Page 117
72 Vitousek et al. (1997).
73 Kasperson et al. (1995), p. 524.
74 Kates and Clark (1996).
75 Turner et al. (1990b).
76 World Bank (1992).
77 First discovered by Grossman and Krueger (1991); for review of debate, see e.g., Arrow et al. (1995).
78 National Research Council reports (for most recent list and full texts, see http:// www.nap.edu) related to atmosphere and climate include:
A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change. Panel on Aerosol Radiative Forcing and Climate Change. (1996).
Acid Deposition: Atmospheric Processes in Eastern North America. Committee on Atmospheric Transport and Chemical Transformation in Acid Precipitation. (1983).
Acid Deposition: Long-Term Trends. Committee on Monitoring and Assessment of Trends in Acid Deposition. (1986).
Air Pollution, the Automobile, and Public Health. Eds. Ann Watson, Richard Bates, and Donald Kennedy. (1998).
Air Quality, Environment, and Energy. Transportation Research Board. (1992).
Atmosphere-Biosphere Interactions: Toward a Better Understanding of the Ecological Consequences of Fossil Fuel Combustion. Committee on the Atmosphere and Biosphere. (1981).
Carbon Dioxide and Climate Change. NAS Colloquium. Proceedings of the National Academy of Sciences. (1997).
China and Global Change: Opportunities for Collaboration. Panel on Global Climate and Sciences in China. (1992).
Clean Air and Highway Transportation: Mandates, Challenges, and Research Opportunities. Transportation Research Board. (1997).
Climate, Climatic Change, and Water Supply. Geophysics Research Board. (1977).
Coastal Meteorology: A Review of the State of the Science. Committee on Meteorological Analysis, Prediction and Research. (1992).
Confronting Climate Change: Strategies for Energy Research and Development. Committee on Alternative Energy Research and Development Strategies. (1990).
Decade-to-Century-Scale Climate Variability and Change: A Science Strategy. Panel on Climate Variability on Decade-to-Century Time Scales. (1998).
Expanding Metropolitan Highways: Implications for Air Quality and Energy Use. Transportation Research Board. (1995).
Global Change and Our Common Future: Papers from a Forum. Committee on Global Change. (1989).
Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project: A Review of Progress and Opportunities. GEWEX Panel. (1998).
Global Environmental Change: Research Pathways for the Next Decade. Committee on Global Change Research. (1999).
GOALS (Global Ocean-Atmosphere-Land System) for Predicting Seasonal-to-Interannual Climate: A Program of Observation, Modeling and Analysis. Climate Research Committee. (1994).
Haze in the Grand Canyon: An Evaluation of the Winter Haze Intensive Tracer Experiment. Committee on Haze in National Parks and Wilderness Areas. (1990).
Learning to Predict Climate Variations Associated with El Niño and the Southern Oscillation: Accomplishments and Legacies of the TOGA Program. Advisory Panel for the Tropical Oceans and Global Atmosphere Program. (1996).
Page 118
Making Climate Forecasts Matter. Panel on the Human Dimensions of Seasonal-to-Interannual Climate Variation. Eds. Paul C. Stern and William E. Easterling. (1999).
Natural Climate Variability on Decade-to-Century Time Scales. Climate Research Committee. (1995).
Ozone Depletion, Greenhouse Gases, and Climate Change. Proceedings of a Joint Symposium by the Board on Atmospheric Sciences and Climate and the Committee on Global Change Research. (1989).
Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base. Committee on Science, Engineering and Public Policy. (1992).
Policy Implications of Greenhouse Warming—Synthesis Panel. Committee on Science, Engineering and Public Policy. (1991).
Research Priorities for Airborne Particulate Matter. Committee on Research Priorities for Airborne Particulate Matter. (1998).
Research Strategies for the U.S. Global Change Research Program. Committee on Global Change. (1990).
Rethinking the Ozone Problem in Urban and Regional Air Pollution. Committee on Tropospheric Ozone Formation and Measurement. (1991).
Review of the North American Research Strategy for Tropospheric Ozone (NARSTO) Program. (1998).
Solar Influences on Global Change. Board on Global Change. (1994).
The Atmospheric Effects of Stratospheric Aircraft Project: An Interim Review of Science and Progress. Panel on the Atmospheric Effects of Aviation. (1998).
The Atmospheric Sciences Entering the Twenty-First Century. Board on Atmospheric Sciences and Climate. (1998).
The U.S. Global Change Research Program: An Assessment of the FY 1991 Plans. Committee on Global Change. (1990).
The United States Antarctic Research Report to the Scientific Committee on Antarctic Research (SCAR): Number 32 - 1990. Polar Research Board. (1991).
Toward a Sustainable Future: Addressing the Long-Term Effects of Motor Vehicle Transportation on Climate and Ecology. Transportation Research Board. (1997).
79 Atmospheric chemistry of the chlorofluorocarbons, Rowland and Molina (1975); ozone hole over the Antarctic, Farman et al. (1985); chemical explanation, Crutzen et al. (1986); Solomon et al. (1986); Anderson et al. (1989); treaty background, Benedick (1991).
80 Montzka et al. (1996).
81 IPCC (1996); see Mahlman (1997).
82 WRI (1996).
83 IPCC (1996), pp. 6-7.
84 Logan (1994); Simmonds et al. (1997).
85 Lee et al. (1998).
86 Husain et al. (1998); NRC (1986).
87 Husain et al. (1998).
88 Khalil and Rasmussen (1994); Novelli et al. (1994); Simmonds et al. (1997).
89 Ibid.
90 National Research Council reports (for most recent list and full texts, see http:// www.nap.edu) related to the oceans include:
A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change. Panel on Aerosol Radiative Forcing and Climate Change. (1996).
A Scientific Strategy for U.S. Participation in the GOALS (Global Ocean-Atmosphere-Land System) Component of the CLIVAR (Climate Variability and Predictability) Programme. GOALS Panel, Climate Research Committee. (1998).
Page 119
Alternatives for Inspecting Outer Continental Shelf Operations. Committee on Alternatives for Inspecting Outer Continental Shelf Operations. (1990).
An Assessment of Atlantic Bluefin Tuna. Committee to Review Atlantic Bluefin Tuna. (1994).
Applications of Analytical Chemistry to Oceanic Carbon Cycle Studies. Committee on Oceanic Carbon. (1993).
Assessment of the U.S. Outer Continental Shelf Environmental Studies Program I: Physical Oceanography. Committee to Review the Outer Continental Shelf Environmental Studies Program. (1990).
Assessment of the U.S. Outer Continental Shelf Environmental Studies Program II: Ecology. Committee to Review the Outer Continental Shelf Environmental Studies Program. (1992).
Assessment of the U.S. Outer Continental Shelf Environmental Studies Program III: Social and Economic Studies. Committee to Review the Outer Continental Shelf Environmental Studies Program. (1993).
Assessment of the U.S. Outer Continental Shelf Environmental Studies Program IV: Lessons and Opportunities. Committee to Review the Outer Continental Shelf Environmental Studies Program. (1993).
Beach Nourishment and Protection. Committee on Beach Nourishment and Protection. (1995).
Biodiversity. Ed. E. O. Wilson. (1988).
Building Ocean Science Partnerships: The U.S. and Mexico Working Together. Committee on U.S.-Mexico Collaboration for Ocean Science. (1998).
Causes and Management of Coastal Eutrophication. Ocean Studies Board, Water Science and Technology Board. (1999).
Clean Ships, Clean Ports, Clean Oceans: Controlling Garbage and Plastic Wastes at Sea. Committee on Shipborne Wastes. (1995).
Coastal Meteorology: A Review of the State of the Science. Committee on Meteorological Analysis, Prediction, and Research. (1992).
Contaminated Marine Sediments: Assessment and Remediation. Committee on Contaminated Marine Sediments. (1989).
Contaminated Sediments in Ports and Waterways: Cleanup Strategies and Technologies. Committee on Contaminated Marine Sediments. (1997).
Double-Hull Tanker Legislation: An Assessment of the Oil Pollution Act of 1990. Committee on Oil Pollution Act of 1990 (Section 4115) Implementation Review. (1998).
Dredging Coastal Ports: An Assessment of the Issues. Technical Panel on Ports, Harbors, and Navigational Channels. (1985).
Environmental Information for Alaskan Outer Continental Shelf Oil and Gas Decisions. Committee to Review Alaskan Outer Continental Shelf Environmental Information. (1994).
Environmental Science in the Coastal Zone: Issues for Further Research. Proceedings of a Retreat. (1994).
Four-Dimensional Model Assimilation of Data: A Strategy for the Earth System Sciences. Panel on Model-Assimilated Data Sets for Atmospheric and Oceanic Research. (1991).
Geodesy in the Year 2000. Committee on Geodesy. (1990).
Global Change and Our Common Future: Papers from a Forum. Committee on Global Change. (1989).
Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project: A Review of Progress and Opportunities. GEWEX Panel. (1998).
Page 120
Global Ocean Science: Toward an Integrated Approach. Committee on Major U.S. Oceanographic Research Programs. (1998).
GOALS (Global Ocean-Atmosphere-Land System) for Predicting Seasonal-to-Interannual Climate: A Program of Observation, Modeling, and Analysis. GOALS Panel. Climate Research Committee. (1994).
International Network of Global Fiducial Stations: Science and Implementation Issues. Panel on Global Network of Fiducial Sites. (1991).
Managing Coastal Erosion. Committe on Coastal Erosion Zone Management. (1990).
Managing Troubled Waters: The Role of Marine Environmental Monitoring. Committe on a Systems Assessment of Marine Environmental Monitoring. (1990).
Managing Wastewater in Coastal Urban Areas. Committee on Wastewater Management for Coastal Urban Areas. (1993).
Marine Aquaculture: Opportunities for Growth. Committee on Assessment of Technology and Opportunities for Marine Aquaculture in the U.S. (1992).
Material Fluxes on the Surface of the Earth. Board on Earth Sciences and Resources. (1990).
Measuring and Understanding Coastal Processes. Committee on Coastal Engineering Measurement Systems. (1989).
Monitoring Southern California's Coastal Waters. Panel on the Southern California Bight. (1990).
National Collaboratories: Applying Information Technology for Scientific Research. Committee on a National Collaboratory: Establishing the User and Developer Partnership. (1993).
Natural Climate Variability on Decade-to-Century Time Scales. Climate Research Committee. (1995).
North American Continent-Ocean Transects Program. U.S. Geodynamics Committee. (1989).
Nutrient Requirements of Fish. Committee on Animal Nutrition, Subcommittee on Fish Nutrition. (1993).
Oceanography in the Next Decade: Building New Partnerships. Ocean Studies Board. (1993).
Opportunities and Needs in Coastal Engineering Research and Education. Committee on Opportunities in the Hydrologic Sciences. (1998).
Opportunities and Priorities in Arctic Geoscience. Committee on Arctic Solid-Earth Geosciences. (1991).
Opportunities in Ocean Sciences: Challenges on the Horizon. Ocean Studies Board. (1999).
Opportunities in the Hydrologic Sciences. Committee on Opportunities in the Hydrologic Sciences. (1990).
Opportunities to Improve Marine Forecasting. Committee on Opportunities to Improve Marine Observations and Forecasting. (1989).
Our Seabed Frontier: Challenges and Choices. Committee on Seabed Utilization in the Exclusive Economic Zone. (1989).
Priorities for Coastal Ecosystem Science. Committee to Identify High-Priority Science to Meet National Coastal Needs. (1995).
Reassessment of the Marine Salvage Posture of the United States. Committee on Marine Salvage Issues. (1994).
Responding to Changes in Sea Level: Engineering Implications. Committee on Engineering Implications of Changes in Relative Sea Level. (1987).
Restoring and Protecting Marine Habitat: The Role of Engineering and Technology. Committee on the Role of Technology in Marine Habitat. (1994).
Page 121
Science and Stewardship in the Antarctic. Committee on Antarctic Policy and Science. (1993).
Science Policy and the Coast: Improving Decision-Making. Committee on Science and Policy for the Coastal Ocean. (1996).
Sea-Level Change. Geophysics Study Committee, Panel on Sea Level Change. (1990).
Solar Influences on Global Change. Board on Global Change. (1994).
Stemming the Tide: Controlling Introductions of Nonindigenous Species by Ships' Ballast Water. Committee on Ships' Ballast Operations. (1996).
Striking a Balance: Improving Stewardship of Marine Areas. Committee on Marine Area Governance and Management. (1997).
Sustaining Marine Fisheries. Committee on Ecosystem Management for Sustainable Marine Fisheries. (1998).
Tanker Spills: Prevention by Design. Committee on Tank Vessel Design. (1991).
The Bering Sea Ecosystem. Committee on the Bering Sea Ecosystem. (1996).
The Global Ocean Observing System: Users, Benefits, and Priorities. Committee to Review U.S. Planning for a Global Ocean Observing System. (1997).
The Ocean's Role in Global Change: Progress of Major Research Programs. Ocean Studies Board. (1994).
The United States Antarctic Research Report to the Scientific Committee on Antarctic Research (SCAR) Number 32 - 1990. Polar Research Board. (1991).
Understanding Marine Biodiversity. Committee on Biological Diversity in Marine Systems. (1995).
Upstream: Salmon and Society in the Pacific Northwest. Committee on Protection and Management of Pacific Northwest Anadromous Salmonids. (1996).
Using Oil Spill Dispersants on the Sea. Committee on the Effectiveness of Oil Spill Dispersants. (1989).
91 Jickells et al. (1990).
92 Walker (1990).
93 NRC (1994).
94 Douglas (1995).
95 NRC (1995a).
96 FAO (1997).
97 NMFS (1997).
98 NRC (1999a).
99 NRC (1999a).
100 NMFS (1996).
101 NRC (1996).
102 NRC (1995b).
103 NRC (1998b).
104 NRC (1996).
105 NRC (1998b).
106 E.g., NRC (1996), Ch. 13.
107 NRC (1998b).
108 Costanza et al. (1998); NRC (1998b).
109 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to fresh water include:
A New Era for Irrigation. Committee on the Future of Irrigation in the Face of Competing Demands. (1996).
A Review of the USGS National Water Quality Assessment Pilot Program. Committee to Review the USGS National Water Quality Assessment Pilot Program. (1990).
Page 122
Alternatives for Ground Water Cleanup. Committee on Ground Water Cleanup Alternatives. (1994).
Assessment of Water Resources Project Planning Procedures. Water Science and Technology Board. (1999).
Climate, Climatic Change, and Water Supply. Panel on Water and Climate. (1977).
Colorado River Ecology and Dam Management: Proceedings of a Symposium, May 24–25, 1990, Santa Fe, New Mexico. Committee to Review the Glen Canyon Environmental Studies. (1991).
Drinking Water and Health. Volumes 5, 6, 7, 8, 9. Safe Drinking Water Committee. (1983-1989).
Drought Management and Its Impact on Public Water Systems. Report of a Symposium Sponsored by the Water Science and Technology Board. (1986).
Freshwater Ecosystems: Revitalizing Educational Programs in Limnology. Committee on Inland Aquatic Ecosystems. (1996).
Ground Water and Soil Contamination Remediation: Toward Compatible Science, Policy, and Public Perception: Report of a Colloquium. Sponsored by the Water Science and Technology Board. (1990).
Ground Water at Yucca Mountain: How High Can it Rise? Panel on Hydrologic/Tectonic/Hydrothermal Systems at Yucca Mountain. (1992).
Ground Water Models: Scientific and Regulatory Applications. Committee on Ground Water Modeling Assessment. (1990).
Ground Water Recharge Using Waters of Impaired Quality. Committee on Ground Water Recharge. (1994).
Ground Water Vulnerability Assessment: Predicting Relative Contamination Potential Under Conditions of Uncertainty. Committee on Techniques for Assessing Ground Water Vulnerability. (1993).
Hazardous Waste Site Management: Water Quality Issues. Report of a Colloquium. Water Science and Technology Board. (1988).
Hydrologic Sciences: Taking Stock and Looking Ahead. Proceedings of the 1997 Abel Wolman Distinguished Lecture and Symposium on the Hydrologic Sciences. Water Science and Technology Board. (1998).
Irrigation-Induced Water Quality Problems. Committee on Irrigation Induced Water Quality Problems. (1989).
Issues in Potable Reuse: The Viability of Augmenting Drinking Water Supplies with Reclaimed Water. Committee to Evaluate the Viability of Augmenting Potable Water Supplies with Reclaimed Water. (1998).
Managing Wastewater in Coastal Urban Areas. Committee on Wastewater Management for Coastal Urban Areas. (1993).
Managing Water Resources in the West Under Conditions of Climate Uncertainty: A Proceedings of a Colloquium. Committee on Climate Uncertainty and Water Resources Management. (1991).
Mexico City's Water Supply: Improving the Outlook for Sustainability. Joint Academies Committee on the Mexico City Water Supply. (1995).
Nature and Human Society: The Quest for a Sustainable World. Committee for the Second Forum on Biodiversity. Eds. Peter Raven and Tania Williams. (1999).
New Directions in Water Resources Planning for the U.S. Army Corps of Engineers. Committee to Assess the U.S. Army Corps of Engineers Water Resources Project Planning Procedures. (1999).
New Strategies for America's Watersheds. Committee on Watershed Management. (1999).
Page 123
Opportunities in the Hydrologic Sciences. Committee on Opportunities in the Hydrologic Sciences. (1991).
Preparing for the Twenty-First Century: A Report to the USGS Water Resources Division. Committee on USGS Water Resources Research. (1991).
Proceedings of the 1997 Abel Wolman Distinguished Lecture and Symposium on the Hydrologic Sciences. Water Science and Technology Board. (1997).
Restoration of Aquatic Ecoystems: Science, Technology and Public Policy. Committee on Restoration of Aquatic Ecosystems. (1992).
Safe Water from Every Tap: Improving Water Service to Small Communities. Committee on Small Water Supply Systems. (1997).
Setting Priorities for Drinking Water Contaminants. Committee on Drinking Water Contaminants. (1998).
Soil and Water Quality: An Agenda for Agriculture. Committee on Long-Range Soil and Water Conservation. (1993).
Sustaining our Water Resources. Water Science and Technology Board. (1993).
Toward Sustainability: Soil and Water Research Priorities for Developing Countries. Committee on International Soil and Water Research and Development. (1991).
Upstream: Salmon and Society in the Pacific Northwest. Committee on Protection and Management of Pacific Northwest Anadromous Salmonids. (1996).
Use of Reclaimed Water and Sludge in Food Crop Production. Committee on the Use of Treated Municipal Wastewater Effluents and Sludge in the Production of Food Crops. (1996).
Valuing Ground Water: Economic Concepts and Approaches. Committee on Valuing Ground Water. (1997).
Water for the Future: The West Bank and Gaza Strip, Israel, and Jordan. Committee on Sustaining Water Supplies for the Middle East. (1999).
Water Transfers in the West: Efficiency, Equity and the Environment. Committee on Western Water Management. (1992).
Wetlands: Characteristics and Boundaries. Committee on Characterization of Wetlands. (1995).
110 Increased water withdrawals, Shiklomanov (1993); reflecting-term trend of increasing withdrawals per capita (L'vovich and White (1990).
111 UN (1997b).
112 Gleick (1998).
113 Gleick (1998), based on Shiklomanov (1993) and UN (1992).
114 Gleick (1998).
115 WRI (1998), NRC (1999b).
116 UN (1997b).
117 WHO (1996c).
118 UN (1997a).
119 Africa and Asia, Raskin (1997); Middle East, NRC (1999b).
120 UN (1997b).
121 Margat (1996).
122 NRC (1998a).
123 UN (1997a).
124 L'vovich and White (1990).
125 Nonrenewable aquifers, Schwarz et al. (1990); distant rivers, Kahrl (1982); husbanding and recycling, Bouwer (1992); NRC (1998a).
126 Raskin, Hansen, and Margolis (1995).
127 WRI (1998).
128 UN (1997a).
Page 124
129 WRI (1998).
130 UNEP (1996).
131 Gleick (1998).
132 Ibid.
133 Anderson (1991); the lack of adequate facilities, Gleick (1998); increase in algal blooms, Patz et al. (1996).
134 Gleick (1998); Raskin (1997).
135 NRC (1999b).
136 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to land include:
A New Era for Irrigation. Committee on the Future of Irrigation in the Face of Competing Demands. (1996).
A Scientific Strategy for U.S. Participation in the GOALS (Global Ocean-Atmosphere-Land System) Component of CLIVAR (Climate Variability and Predictability) Programme. GOALS Panel, Climate Research Committee. (1998).
Agricultural Crop Issues and Policies. Committee on Managing Global Genetic Resources: Agricultural Imperatives. (1993).
Alternative Agriculture. Committee on the Role of Alternative Farming Methods in Modern Production Agriculture. (1989).
Biologic Markers of Air-Pollution Stress and Damage in Forests. Committee on Biologic Markers of Air Pollution Damage. (1989).
Biotechnology Unzipped: Promises and Realities. Eric S. Grace. Joseph Henry Press. (1997).
China and Global Change: Opportunities for Collaboration. Panel on Global Climate Change Sciences in China. (1992).
Colleges of Agriculture at the Land Grant Universities: A Profile. Committee on the Future of Land Grant Colleges of Agriculture. (1995).
Colleges of Agriculture at the Land Grant Universities: Public Service and Public Policy. Committee on the Future of Land Grant Colleges of Agriculture. (1996).
Cooperating With Nature: Confronting Natural Hazards with Land-Use Planning for Sustainable Communities. Ed. Raymond J. Burby. Joseph Henry Press. (1998).
Designing an Agricultural Genome Program. Board on Biology. (1998).
Ecological Risks: Perspectives from Poland and the United States. Eds. Wladyslaw Grodzinski, Ellis Cowling, Alicia Breymeyer and Anna Phillips. (1990).
Ecologically Based Pest Management: New Solutions for a New Century. Committee on Pest and Pathogen Control Through Management of Biological Control Agents. (1996).
Flood Risk Management and the American River Basin: An Evaluation. Committee on Flood Control Alternatives in the American River Basin. (1995).
Food Aid Projections for the Decade of the 1990s. Panel on Food Aid Requirements for the 1990s. (1989).
Forest Trees. Committee on Managing Global Genetic Resources: Agricultural Imperatives. (1991).
Forested Landscapes in Perspective: Prospects and Opportunities for Sustainable Management of America's Nonfederal Forests. Committee on Prospects and Opportunities for Sustainable Management of America's Nonfederal Forests. (1998).
Forestry Research: A Mandate for Change. Committee on Forestry Research. (1990).
Forests of the Pacific Northwest. Committee on Environmental Issues in Pacific Northwest Forest Management. (1998).
Future of Pesticides in Pest Management for U.S. Agriculture. Board on Environmental Studies and Toxicology. (1999).
Page 125
Genetic Engineering of Plants: Agricultural Research Opportunities and Policy Concerns. Board on Agriculture. (1984).
Grasslands and Grassland Sciences in Northern China. Office of International Affairs. (1992).
Investing in Research: A Proposal to Strengthen the Agricultural, Food, and Environmental System. Board on Agriculture. (1989).
Irrigation-Induced Water Quality Problems: Planning for Remediation. Committee on Irrigation-Induced Water Quality Problems. (1996).
Land Use Planning and Oil and Gas Leasing on Onshore Federal Lands. Committee on Onshore Oil and Gas Leasing. (1989).
Livestock. Committee on Managing Global Genetic Resources: Agricultural Imperatives. (1993).
Lost Crops of Africa: Volume I: Grains. Board on Science and Technology for International Development. (1996).
Lost Crops of the Incas: Little-Known Plants of the Andes with Promise for Worldwide Cultivation. Panel on Lost Crops of the Incas. (1989).
Marine Aquaculture: Opportunities for Growth. Committee on Assessment of Technology and Opportunities for Marine Aquaculture in the U.S. (1992).
Microlivestock: Little-Known Small Animals with a Promising Future. Board on Science and Technology for International Development. (1991).
Mitigating Losses from Land Subsidence in the United States. Committee on Grand Failure Hazards Mitigation Panel on Land Subsidence. (1991).
Neem: A Tree for Solving Global Problems. Board on Science and Technology for International Development. (1992).
New Directions for Biosciences Research in Agriculture: High-Reward Opportunities. Committee on Biosciences Research in Agriculture. (1985).
Nutrient Requirements of Dairy Cattle. Committee on Animal Nutrition, Subcommittee on Dairy Cattle. (1989).
Nutrient Requirements of Fish. Committee on Animal Nutrition, Subcommittee on Fish Nutrition. (1993).
Nutrient Requirements of Horses. Committee on Animal Nutrition, Subcommittee on Horse Nutrition. (1989).
One Earth, One Future: Our Changing Global Environment. Cheryl Silver and Ruth DeFries. (1992).
Plant Biology Research and Training for the 21st Century. Committee on an Examination of Plant-Science Research Programs in the U.S. (1992).
Population and Land Use in Developing Countries: Report of a Workshop. Committee on Population. (1993).
Precision Agriculture in the 21st Century: Geospatial and Information Technologies in Crop Management. Committee on Assessing Crop Yield: Site-Specific Farming, Information Systems, and Research Opportunities. (1997).
Quality Protein Maize. Board on Science and Technology for International Development. (1988).
Rangeland Health: New Methods to Classify, Inventory, and Monitor Rangelands. Committee on Rangeland Classification. (1994).
Regenerating Agriculture: Policies and Practice for Sustainability and Self-Reliance. Jules N. Pretty. (1995).
Saline Agriculture: Salt Tolerant Plants for Developing Countries. Panel on Saline Agriculture for Developing Countries, Board on Science and Technology for International Development. (1990).
Page 126
Setting Priorities for Land Conservation. Committee on Scientific and Technological Criteria for Federal Acquisition of Lands for Conservation. (1993).
Soil and Water Quality: An Agenda for Agriculture. Committee on Long-Range Soil Soil and Water Conservation. (1993).
Soil Conservation: An Assessment of the National Resources Inventory, Volume 1 and Volume 2. Committee on Conservation Needs and Opportunities. (1986).
Sustainable Agriculture and the Environment in the Humid Tropics. Committee on Sustainable Agriculture and the Environment in the Humid Tropics. (1993).
Sustainable Agriculture Research and Education in the Field: A Proceedings. Board on Agriculture. (1991).
Technological Trajectories and the Human Environment. Eds. Jesse Ausubel and H. Dale Langford. (1997).
The U.S. National Plant Germplasm System. Committee on Managing Global Genetic Resources: Agricultural Imperatives. (1991).
Toward Sustainability: A Plan for Collaborative Research on Agriculture and Natural Resource Management. Panel for Collaborative Research Support for AID's Sustainable Agriculture and Natural Resources Management Program. (1991).
Toward Sustainability: Integrated Pest Management as a Component of Sustainability Research. Subpanel on Integrated Pest Management, Panel for Collaborative Research Support for AID's Sustainable Agriculture and Natural Resources Management Program. (1992).
Toward Sustainability: Soil and Water Research Priorities for Developing Countries. Committee on International Soil and Water Research and Development. (1991).
Understanding Agriculture: New Directions for Education. Committee on Agricultural Education in Secondary Schools. (1998).
Use of Reclaimed Water and Sludge in Food Crop Production. Committee on the Use of Treated Municipal Wastewater Effluents and Sludge in Food Crop Production. (1996).
Vetiver Grass: A Thin Green Line Against Erosion. Board on Science and Technology for International Development. (1993).
Wood in Our Future: The Role of Life-Cycle Analysis: Proceedings of a Symposium. Board on Agriculture. (1997).
Xenotransplantation: Science, Ethics, and Public Policy. Institute of Medicine, Committee on Xenograft Transplantation: Ethical Issues and Public Policy. (1996).
137 Richards (1990).
138 Rozanov et al. (1990).
139 Hayami and Ruttan (1985).
140 Pinstrup-Anderson et al. (1997).
141 Ausubel (1996b).
142 Rasmussen et al. (1998).
143 Khush (1995); Naylor (1996).
144 Matson et al. (1997).
145 Walsh (1991).
146 Williams (1990).
147 Noble and Dirizo (1997).
148 Williams (1990).
149 Noble and Dirizo (1997).
150 Ciais et al. (1995).
151 Simpson et al. (1996).
152 Noble and Dirizo (1997).
Page 127
153 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to species and ecosystems include:
A Biological Survey for the Nation. Committee on the Formation of the National Biological Survey. (1993).
An Assessment of Atlantic Bluefin Tuna. Committee to Review Atlantic Bluefin Tuna. (1994).
An Evaluation of the U.S. Navy's Extremely Low Frequency Submarine Communications Ecological Monitoring Program. Committee to Evaluate the U.S. Navy's Exteremely Low Frequency Submarine Communications Ecological Monitoring Program. (1997).
Assessment of the U.S. Outer Continental Shelf Environmental Studies Program I: Ecology. Committee to Review the Outer Continental Shelf Environmental Studies Program. (1992).
Biodiversity. Ed. E. O. Wilson. (1988).
Biodiversity Conservation in Transboundary Protected Areas. Proceedings of an International Workshop, Bieszczady and Tatra National Parks, Poland. Eds. A. I. Breymeyer, R. D. Noble, and S. Deets. (1996).
Biodiversity II: Understanding and Protecting Our Biological Resources. Marjorie Reaka-Kudla, Don Wilson, and E. O. Wilson. Joseph Henry Press. (1995).
Building a Foundation for Sound Environmental Decisions. Committee on Research Opportunities and Priorities for EPA. (1997).
Chemical Ecology: The Chemistry of Biotic Interaction. Eds. Thomas Eisner and Jerrold Meinwald. (1995).
China and Global Change: Opportunities for Collaboration. Panel on Global Climate Change Sciences in China. (1992).
Colorado River Ecology and Dam Management: Proceedings of a Symposium May 24–25, 1990. Committee to Review the Glen Canyon Environmental Studies. (1991).
Conserving Biodiversity: A Research Agenda for Development Agencies. Panel on Biodiversity Research Priorities, Board on Science and Technology for International Development. (1992).
Contaminated Marine Sediments: Assessment and Remediation. Committee on Contaminated Marine Sediments. (1989).
Contaminated Sediments in Ports and Waterways: Cleanup Strategies and Technologies. Committee on Contaminated Marine Sediments. (1997).
Decline of the Sea Turtles: Causes and Prevention. Committee on Sea Turtle Conservation. (1990).
Dolphins and the Tuna Industry. Committee on Reducing Porpoise Mortality from Tuna Fishing. (1992).
Ecological Knowledge and Environmental Problem-Solving: Concepts and Case Studies. Committee on Applications of Ecological Theory to Environmental Problems. (1986).
Ecological Risks: Perspectives from Poland and the United States. Eds. Wladyslaw Grodzinski, Ellis Cowling, Alicia Breymeyer and Anna Phillips. (1990).
Ecologically-Based Pest Management: New Solutions for a New Century. Committee on Pest and Pathogen Control Through Management of Biological Control Agents. (1996).
Effects of Past Global Change on Life. Board on Earth Sciences and Resources. (1995).
Engineering Within Ecological Constraints. Ed. Peter C. Schulze. (1996).
Forest Trees. Committee on Managing Global Genetic Resources: Agricultural Imperatives. (1991).
Page 128
Freshwater Ecosystems: Revitalizing Educational Programs in Limnology. Committee on Inland Aquatic Ecosystems. (1996).
Grasslands and Grassland Sciences in Northern China. Office of International Affairs. (1992).
Improving Fish Stock Assessments. Committee on Fish Stock Assessment Methods. (1998).
Land Use Planning and Oil and Gas Leasing on Onshore Federal Lands. Committee on Onshore Oil and Gas Leasing. (1989).
Linking Science and Technology to Society's Environmental Goals. National Forum on Science and Technology Goals. (1996).
Measures of Environmental Performance and Ecosystem Conditions. NAE. Ed. Peter Schulze. (1999).
Nature and Human Society: The Quest for a Sustainable World. Committee for the Second Forum on Biodiversity. Eds. Peter Raven and Tania Williams. (1999).
New Strategies for America's Watersheds. Committee on Watershed Management. (1999).
Perspectives on Biodiversity: Valuing Its Role in an Everchanging World. Committee on Economic and Noneconomic Value of Biodiversity. (1999).
Priorities for Coastal Ecosystem Science. Committee to Identify High-Priority Science to Meet National Coastal Needs. (1995).
Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy. Committee on the Restoration of Aquatic Ecosystems. (1992).
River Resource Management in the Grand Canyon. Committee to Review the Glen Canyon Environmental Studies. (1996).
Science and the Endangered Species Act. Committee on Scientific Issues in the Endangered Species Act. (1995).
Shaping the Future: Biology and Human Values. Steve Olson. (1989).
Sharing the Fish: Toward a National Policy on Individual Fishing Quotas. Committee to Review Individual Fishing Quotas. (1999).
Soil and Water Quality: An Agenda for Agriculture. Committee on Long-Range Soil and Water Conservation. (1993).
Stemming the Tide: Controlling Introductions of Nonindigenous Species by Ships' Ballast Water. Committee on Ships' Ballast Operations. (1996).
Sustaining Marine Fisheries. Committee on Ecosystem Management for Sustainable Marine Fisheries. (1999).
Technological Trajectories and the Human Environment. NAE. Eds. Jesse H. Ausubel and H. Dale Langford. (1997).
The Bering Sea Ecosystem. Committee on the Bering Sea Ecosystem. (1996).
The Greening of Industrial Ecosystems. NAE. Eds. Braden Allenby and Deanna Richards. (1994).
The Mono Basin Ecosystem: Effects of Changing Lake Level. Mono Basin Ecosystem Study Committee. (1987).
The Ocean's Role in Global Change: Progress of Major Research Programs. Ocean Studies Board. (1994).
The Scientific Bases for Preservation of the Hawaiian Crow. Committee on the Scientific Bases for the Preservation of the Hawaiian Crow. (1992).
The Scientific Bases for Preservation of the Mariana Crow. Committee on the Scientific Bases for the Preservation of the Mariana Crow. (1997).
Toward a Sustainable Future: Addressing the Long-Term Effects of Motor Vehicle Transportation on Climate and Ecology. Transportation Research Board. (1997).
Page 129
Understanding Marine Biodiversity: A Research Agenda for the Nation. Committee on Biological Diversity in Marine Systems. (1995).
Upstream: Salmon and Society in the Pacific Northwest. Committee on Protection and Management of Pacific Northwest Anadromous Salmonids. (1996).
Wetlands: Characteristics and Boundaries. Committee on Characterizations of Wetlands. (1995).
Wolves, Bears, and Their Prey in Alaska: Biological and Social Challenges in Wildlife Management. Committee on Management of Wolf and Bear Populations in Alaska. (1997).
154 The five commonly recognized mass extinctions of species were the Ordovician 440 million years ago, the Devonian 365 million years ago, the Permian 245 million years ago, the Triassic 210 million years ago, and the Cretaceaous 65 million years ago (see Wilson 1993, Ch. 3).
155 Lawton and May (1995).
156 Barbault and Sastrapradja (1995).
157 MacDonald et al. (1989).
158 NRC (1995b).
159 Cohen and Carlton (1995).
160 NRC (1995b).
161 IUCN (1996).
162 McAllister et al. (1997); NRC (1996).
163 Newell (1988); Lovejoy (1997).
164 Burke et al. (1998).
165 Daily (1997).
166 NRC (1988).
167 Ecological Society of America (1996); Daily (1997).
168 National Research Council reports (for most recent list and full texts, see http://www.nap.edu) related to disease organisms and vectors include:
Adverse Effects of Pertussis and Rubella Vaccines. Committee to Review the Adverse Consequences of Pertussis and Rubella Vaccines. (1991).
AIDS and Behavior: An Integrated Approach. Committee on Substance Abuse and Mental Health Issues in AIDS Research. (1994).
AIDS, Sexual Behavior, and Intravenous Drug Use. Committee on AIDS Research and the Behavioral, Social, and Statistical Sciences. (1989).
AIDS: The Second Decade. Committee on AIDS Research and the Behavioral, Social, and Statistical Sciences. (1990).
Antimicrobial Resistance: Issues and Options. Forum on Emerging Infections. Eds. Polly F. Harrison and Joshua Lederberg. (1998).
Assessing the Social and Behavioral Science Base for HIV/AIDS Prevention and Intervention: Workshop Summary. Committee on the Social and Behavioral Science Base for HIV/AIDS Prevention and Intervention. (1995).
Cattle Inspection. Committee on Evaluation of USDA Streamlined Inspection System for Cattle. (1990).
Companion Guide to Infectious Diseases of Mice and Rats. Committee on Infectious Diseases of Mice and Rats. (1991).
Conference on Human Health and Global Climate Change—Summary of the Proceedings. Eds. Valerie Setlow and Andrew Pope. (1996).
Confronting AIDS: Directions for Public Health, Health Care, and Research. Committee on a Naitonal Strategy for AIDS. (1986).
Confronting AIDS: Update 1988. Committee for the Oversight of AIDS Activities. (1988).
Page 130
Ecologically Based Pest Management: New Solutions for a New Century. Committee on Pest and Pathogen Control Through Management of Biological Control Agents. (1996).
Effects of Health Programs on Child Mortality in Sub-Saharan Africa. Working Group on the Effects of Child Survival and General Health Programs on Mortality, Committee on Population. (1993).
Emerging Infections: Microbial Threats to Health in the United States. Committee on Microbial Threats to health in the United States. (1992).
Environmental Epidemiology, Volume I: Public Health and Hazardous Wastes. Committee on Environmental Epidemiology. (1991).
Environmental Medicine: Integrating a Missing Element into Medical Education. Committee on Curriculum Development in Environmental Medicine. (1995).
Evaluating AIDS Prevention Programs: Expanded Edition. Committee on AIDS Research and the Behavioral, Social, and Statistical Sciences. (1991).
Factors Affecting Contraceptive Use in Sub-Saharan Africa. Panel on Population Dynamics of Sub-Saharan Africa, Committee on Population. (1993).
Global Environmental Change: Understanding the Human Dimensions. Committee on Human Dimensions of Global Change. (1991).
Global Health in Transition: A Synthesis: Perspectives from International Organizations. Board on International Health. Eds. John H. Bryant and Polly F. Harrison. (1996).
HIV and the Blood Supply: An Analysis of Crisis Decisionmaking. Committee to Study HIV Transmission through Blood and Blood Products. (1995).
In Her Lifetime: Female Morbidity and Mortality in Sub-Saharan Africa. Committee to Study Female Morbidity and Mortality in Sub-Saharan Africa. Ed. Christopher P. Howsen. (1996).
Infectious Diseases in an Age of Change: The Impact of Human Ecology and Behavior on Disease Transmission. Ed. Bernard Roizman. (1995).
Infectious Diseases of Mice and Rats. Committee on Infectious Diseases of Mice and Rats. (1991).
Issues in Potable Reuse: The Viability of Augmenting Drinking Water Supplies with Reclaimed Water. Committee to Evaluate the Viability of Augmenting Potable Water Supplies with Reclaimed Water. (1998).
Linking Research and Public Health Practice: A Review of CDC's Program of Centers for Research and Demonstration of Health Promotion and Disease Prevention. (1997).
Livestock: Managing Global Genetic Resources: Agricultural Imperatives. Committee on Managing Global Genetic Resources: Agricultural Imperatives. Subcommittee on Animal Genetic Resources. (1993).
Malaria: Obstacles and Opportunities. Committee for the Study of Malaria Prevention and Control: Status Review and Alternative Strategy. (1991).
National Academy of Sciences Colloquium: Genetic Engineering of Viruses and Viral Vectors. Proceedings of the National Academy of Sciences. (1996).
New Vaccine Development: Establishing Priorities; Volume II, Diseases of Importance in Developing Countries. Committee on Issues and Priorities for New Vaccine Development. (1986).
Preventing and Mitigating AIDS in Sub-Saharan Africa: Research and Data Priorities for the Social and Behavioral Sciences. Panel on Data and Research Priorities for Arresting AIDS in Sub-Saharan Africa. Eds. Barney Cohen and James Trussell. (1996).
Preventing HIV Transmission: The Role of Sterile Needles and Bleach. Panel on Needle Exchange and Bleach Distribution Programs. (1995).
Rodents. Institute of Laboratory Animal Resources, Committee on Rodents. (1996).
Page 131
The Epidemiological Transition: Policy and Planning Implications for Developing Countries: Workshop Proceedings. Committee on Population, Board on International Health. (1993).
The Hidden Epidemic: Confronting Sexually Transmitted Diseases, Summary. Committee on Prevention and Control of Sexually Transmitted Diseases. (1997).
The Social Impact of AIDS in the United States. Committee on AIDS Research and the Behavioral, Social, and Statistical Sciences. (1993).
Vaccines for the 21st Century: A Tool for Setting Priorities. Committee to Develop Priorities for Vaccine Development. Eds. Kathleen R. Stratton, Jane S. Durah, and Michael A. Stoto. (1998).
Valuing Health Risks, Costs, and Benefits for Environmental Decisionmaking: Report of a Conference. Steering Committee on Valuing Health Risks, Costs, and Benefits for Environmental Decisions. Eds. P. Brett Hammond and Rob Coppock. (1990).
169 WHO (1996a).
170 Ibid.
171 Bradley (1994).
172 WHO (1992).
173 Dobson et al. (1997).
174 Lindsay and Birley (1996).
175 Death from tuberculosis, WHO (1996b): disease and increasing poverty and homelessness in urban areas, Stephens (1996); multidrug resistance, Wilson (1994).
176 WHO (1996b).
177 IOM (1992).
178 See Patz et al. (1996).
