The U.S Global Change Research Program (USGCRP) 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 greatly advance our knowledge about the implications of such change for society. The research successes of the last decade have laid the foundation for a global environmental change information service that will allow global change research results to be applied more effectively to national needs.

    Since its establishment a decade ago, the USGCRP has supported a comprehensive program of scientific research on the multiple issues presented by climatic and other changes in the Earth system. USGCRP-supported research has produced substantial increases in knowledge, predictive understanding, and documented evidence of global environmental change, including major scientific advances in the understanding of stratospheric ozone depletion, the El Niño-Southern Oscillation phenomenon, global climate change, tropical deforestation, and other issues.

    These interlinked problems of global environmental change present long-term challenges at local and regional scales as well. Science has much to contribute to the management of these challenges. In the next decade, the USGCRP will focus on understanding the Earth system as a whole, on the dynamics of environmental change, and on connecting that knowledge to societal needs, including the provision of information on regional implications of change. A series of five broad objectives are guiding the program as it pursues these goals:

1. Determine the origins, rates, and likely future course of natural and anthropogenic changes.
2. Increase understanding of the combined effects of multiple stresses on ecosystems.
3. Understand and model global environmental change and its processes on finer spatial scales and across a wide range of timescales.
4. Address the potential for surprises and abrupt changes in the global environment.
5. Understand and assess the impacts of global environmental change and their consequences for the United States.

    To respond to the scientific challenges described in the Pathways report, the USGCRP will be organized and managed as a series of closely-linked Program Elements. This FY 2000 Implementation Plan and Budget Overview contains detailed descriptions of a series of research challenges and FY 2000 objectives for each Program Element.
 
 
 

1. Understanding the Earth’s Climate System, with a focus on improving our understanding of the climate system as a whole, rather than focusing on its individual components, and thus improving our ability to predict climate change and variability.
2. Biology and Biogeochemistry of Ecosystems, with a focus on improving understanding of the relationship between a changing biosphere and a changing climate and the impacts of global change on managed and natural ecosystems.
3. Composition and Chemistry of the Atmosphere, with a focus on improving our understanding of the global-scale impacts of natural and human processes on the chemical composition of the atmosphere and determining the effect of such changes on air quality and human health.
4. Paleoenvironment and Paleoclimate, with a focus on providing a quantitative understanding of the envelope of natural environmental variability, on timescales from centuries to millennia, within which the effects of human activities on the planet’s biosphere, geosphere, and atmosphere can be assessed.
5. Human Dimensions of Global Change, with a focus on explaining how humans intervene in the Earth system and are themselves affected by the interactions between natural and social processes.
6. The Global Water Cycle, with a focus on improving our understanding of the movement of water through the land, atmosphere, and ocean, and on how global change may increase or decrease regional water availability.