Human Dimensions of Global Environmental Change: Research Pathways for the Next Decade (1999)

• and global scales, particularly as they affect ecosystems and biogeochemical cycles and the human consequences of environmental change.
• Improving methods for decision making about global change. Research should improve ways of estimating nonmarket values of environmental resources, incorporating these values into national accounts, representing uncertainty to decision makers, and structuring decision making procedures and techniques of scientific analysis so as to bring formal analyses together with judgments and thus better meet the needs of decision making participants.
• Improving the integration of human dimensions research with other global change research. Human dimensions research supports each of the other fields of scientific research on global change and also addresses key crosscutting issues. It requires focused and coordinated support that draws on the strengths of both disciplinary and interdisciplinary approaches and that takes advantage of value added by international collaborations.
• Improving geographic links to existing social, economic, and health data. Human dimensions data systems benefit from adding geographic information to ongoing social data collection efforts, with appropriate safeguards for confidentiality. The effectiveness of these data systems depends on adequate and stable support. The time is ripe for a careful review of the observational needs for human dimensions research, with careful attention to the ability to link to other observational systems.

Study of the human dimensions of global environmental change encompasses analysis of the human causes of global environmental transformations, the consequences of such changes for societies and economies, and the ways in which people and institutions respond to the changes. It also involves the broader social, political, and economic processes and institutions that frame human interactions with the environment and influence human behavior and decisions. Significant among these are the processes and institutions that use scientific information about environmental processes and human-environment interactions as inputs to human choices that alter the course of those processes and interactions. Thus, one of the human dimensions of global change involves the practical use of scientific information and the issue of how to make such information more useful for decision making. Beginning with a focus on climate change, human dimensions research is expanding to address changes in biodiversity, land and water, pollution, and other globally significant resources and to draw on the extensive literature that addresses human-environment interactions.

Human transformations of the global environment have a long history. Table 7.1 shows that, since 1700, human activity has converted 19 percent of the world's forests and woodlands to cropland and pasture. This shift has altered bio-

geochemical cycles, land surface characteristics, and ecosystems so much that the Earth system itself has changed significantly.

Human activity, especially fossil fuel consumption since the Industrial Revolution, is also responsible for substantial increases in atmospheric concentrations of such gases as carbon dioxide and methane. These increases (see Table 7.2) are mostly associated with the per capita consumption of fossil fuels and growth of the human population; deforestation and the production of cement, livestock, and rice for human consumption; the disposal of wastes from human settlement in landfalls; and increased use of fertilizers and industrial and agricultural chemicals. The likely consequences of these gas emissions include a warming of the global climate and a reduction in stratospheric ozone.

Such human activities have accelerated rapidly in recent decades. Between 1950 and 2000 the world's population will have increased from 2.5 billion to more than 6 billion people. Total energy consumption increased from 188,000 petajoules annually in 1970 to almost 300,000 petajoules in 1990, and per capita energy consumption increased from about 50 to 57 gigajoules.¹ Between 1970 and 1990, global forest area decreased by 6 percent, irrigated area increased by almost 40 percent, number of cattle increased by 25 percent, and use of chemical fertilizers doubled.²

These changes, which have altered global environmental parameters, are also associated with improved quality of life for many people: average life expectancy has increased 40 percent since 1955—from 47.5 years then to 65 years in 1995—and infant mortality decreased 60 percent—from 155 deaths per 1,000 in 1955 to 60 in 1990.³ The rising global averages of per capita energy use, life expectancy, and infant mortality subsume vast disparities. People do not all contribute equally to global change nor benefit equally from progress. The processes determining these changes, sometimes called driving forces, also differ substantially across regions and populations, affecting future trends in both environmental quality and human well-being.

Regional differences in rates of environmental transformation reflect variations in the human driving forces of global change. In the case of greenhouse gas emissions the increase in coal production in China from 7,400 to 21,700 petajoules from 1970 to 1990 represents a doubling of per capita energy consumption due to economic development and national policies. In Mexico oil production grew from 980 to 6,046 petajoules over the same period, reflecting a doubling in per capita energy consumption, significant population growth, and national development policy choices to increase the export of oil. A loss of 40 million hectares of forest in Brazil since 1970 has significant implications for tropical biodiversity, as do losses of almost 10 million hectares each in Indonesia, Thailand, and Mexico. These trends in deforestation result from different combinations of population growth, migration, and economic and policy forces.⁴ A major focus of human dimensions research is explaining patterns and changes in the rates of environmental transformation in terms of driving forces that act globally, regionally, and at the level of responsible decision makers.

The impacts of global change on societies and economies are expected to increase greatly in the next century. For example, much of the global change that will eventually result from past human activities has yet to occur, and current trends in these activities portend potential large increases in global change. As the major climatic changes lie in the future, so do their implications for humanity. This may also be true for the human consequences of ecological transformations now occurring through deforestation and other anthropogenic land cover changes. Thus, another major focus of human dimensions research is estimating the social and economic consequences of anticipated global environmental changes. This research integrates information about anticipated environmental changes with information on the social parameters that determine the impact of those changes: demand for affected natural resources, vulnerability of geographical regions and social groups to particular environmental changes, and the potential for adaptive response. In addition, human dimensions research addresses the workings of social systems that manage environmental resources—markets, property rights regimes, treaties, legal and informal norms, and so forth—and the potential to modify those institutions through policy and thus to mitigate global change or increase adaptive capability.