U.S. Global Change Research Program
FY 2000 Implementation Plan and Budget Overview

A Vision and Perspective for the Decade Ahead

Setting the Stage for Global Change Research in the 21st Century

The U.S. Global Change Research Program stands at the threshold of a major transition. Over the next several years, in addition to continuing to improve our understanding of the Earth’s environment and how it is changing, the program will advance greatly our understanding of the implications of such change for society. The research successes of the last decade have laid the foundation for establishment of a global environmental change information service that will allow global change research results to be applied more effectively to national needs.

    In the early 1980s, when climate research began in earnest on a global scale, the problem of understanding the entire Earth system seemed in many ways intractable. Climate system behavior, excepting a few well-known features such as the ice ages and the annual march of the seasons, seemed chaotic. Accurate prediction of the future course of change thus appeared very unlikely. Although it was apparent that scientific research was required to increase understanding of a set of newly identified global-scale environmental changes, it was by no means clear where progress was most likely to be achieved.

    In response to this challenge, the establishment of the U.S. Global Change Research Program led to a comprehensive program of support for research across a broad range of Earth system science issues. The result has been a remarkable change in perspective. Scientists discovered the ozone hole, in part through routine surveillance; determined its spatial extent, temporal behavior, and chemical origins; and showed it was caused by human activities. Observations demonstrated a long-term, statistically significant decline in ozone amounts over most of the Earth’s lower atmosphere, much of which is attributable to changes in atmospheric chemistry associated with human activities. A rapid increase in scientific understanding supported a global consensus on steps to ameliorate the problem. Ongoing research and monitoring have shown that the emissions controls on chlorofluorocarbons (CFCs) and related molecules implemented under the Montreal Protocol on Substances That Deplete the Ozone Layer have begun to have an effect, as the concentration of chlorine-containing source gases at the Earth’s surface has begun to decrease. Field experiments, long-term global observations, and computational modeling all played key roles in advancing our scientific understanding of ozone depletion.

    As these events took place, another group of scientists began to pursue studies of El Niño, leading to equally remarkable scientific developments. These studies have shown beyond any doubt that the El Niño-Southern Oscillation process, in which the actions of the ocean and the atmosphere are closely coupled, has some degree of predictability in its behavior. The scientific community, working in the context of the USGCRP, successfully predicted the onset of the 1997-1998 El Niño and some of the resulting climate anomalies around the world. Societies made limited but significant advance preparations; in some cases economic consequences were minimized and loss of lives and property was reduced.

    Coincident with these and other research successes, a large fraction of the research community was achieving an even more visible and significant result. USGCRP-supported observations and analyses played a prominent role in demonstrating that emissions of carbon dioxide and other trace gases resulting from human activities are changing the composition of the atmosphere. Projections indicate that the changes over the next century will increase atmospheric concentrations of greenhouse gases to levels not seen in tens of millions of years — periods when the climate was substantially different than today. Observations suggest that the human-induced changes in atmospheric composition are already starting to change the climate. Careful measurements of surface temperatures around the world indicate that the global average temperature has risen substantially in the latter half of this century, compared both to observed temperatures since the 19th century and to estimated temperatures reconstructed from tree rings and other evidence back as far as a thousand years. Substantial improvements in climate models have been achieved and these models project increases over the next century in global average temperatures of from 2o to 7o F, as well as shifts in precipitation and a significant acceleration in the rate of sea-level rise.

    Observations and monitoring from space of changing land cover, along with the production and distribution of global land cover data, are providing an important foundation for efforts to make land use more sustainable. For example, satellite observations supported by the USGCRP in coordination with international projects have documented and quantified changes in tropical and subtropical land cover, such as the loss of tropical forest in Brazil. Changes in land cover and land use are occurring around the world at an increasingly rapid rate, driven largely by human activities. Research has documented that changes in land cover such as the conversion of forest to pasture in the tropics, and changes in land use such as increases in fertilizer applications to cropland worldwide, are contributing to changes in atmospheric composition and may also contribute to climate change on both regional and global scales.

    The real significance of all these scientific developments is seen most clearly when they are taken together. Several major environmental processes are now understood and there is some degree of predictability in their behaviors. A deeper appreciation of how the Earth’s oceans, atmosphere, and land surface function together as a dynamic system is being gained. Over the next decade, the causes and consequences of an entire suite of interacting large-scale environmental changes will be better understood. The future course of such changes, and the limitations of prediction, will become clearer. Scientific knowledge will improve the preservation and enhancement of environmental quality and the management of environmental change.

    Achieving this vision requires new science findings and better assessment and interpretation of scientific information. The full spectrum of public and private-sector decisionmakers also need routine, reliable, and readily understood scientific insight.

Projections to the Year 2010

    The United States and other nations face an emerging group of environmental problems that are relatively new to public and private-sector institutions. The global reach of such problems means that collective actions are necessary. Yet the interlinked issues of climate change, loss of biodiversity, and land-use and land-cover changes are not only global issues; they present long-term challenges at local and regional scales as well.

    Science has much to contribute to the management of these issues. Longstanding climate-related problems (e.g., droughts, floods, reduced agricultural production, and pest infestations) now can be anticipated to some extent. Better understanding of the complexity of changes on planet Earth, such as temperature and precipitation patterns, creates opportunities to reduce exposure and enhance resiliency in socioeconomic systems.

    Estimating in advance the magnitude of these problems or the value of opportunities to respond is extremely difficult. One thing is already clear, however — current economic measurements alone do not suffice to explain or judge the severity of such problems. The importance of some issues far outstrips any purely economic measurement. Some representative examples:

    The economic value of the understanding gained through the USGCRP cannot be accurately calculated, both because of limitations in current economic methodology and lack of accurate data. It is clear, however, that the total value is significant (on the order of tens of billions of dollars annually). Part of the USGCRP research plan is to improve the ability to document the economic values of USGCRP research and applications, and thus to be able to include such estimates as an input in the research planning process.