The Earth's environment is in a state of continuous change. Continents drift, mountains are driven upwards and erode, animal and plant species evolve, terrestrial and marine ecosystems change, the Earth's orbit about the Sun varies, and the atmosphere and oceans adjust in response to these and numerous other forces that act on our planet. Large changes such as these generally occur very slowly and are the result of major natural forces beyond human influence or control. Over periods of decades to centuries, however, natural changes have been relatively small, at least for the several thousand years before the onset of large-scale agricultural and industrial activities.
Although we are relative newcomers to the scene, humans have now become powerful agents of environmental change, at least initially on time scales of decades to centuries. The chemistry of the atmosphere has been altered by the agricultural and industrial revolutions. Erosion of soils, sediment loading of rivers, and shoreline contours have been influenced dramatically by agriculture and construction. The production and release of toxic chemicals as well as changes in land use and land management have affected the health and distribution of populations of living organisms. The development of water resources has affected patterns of natural water storage, evaporation, and river flow on the world's continents.
With the increasing world population, the expanding global economy, and the development of new technologies, the role of humans as agents of environmental change is likely to become even more significant in the future. The use of fossil fuels is changing atmospheric composition and exerting an increasing warming influence on the global climate. The destruction of forests and certain agricultural practices also contribute to changes in the atmospheric composition and to climate change. Changes in land use alter the ability of the land to provide ecological services, including water purification and habitat for wildlife. The emissions of CFCs and other chlorine-and bromine-containing gases have led to depletion of stratospheric ozone that will take decades to reverse. All of these factors and more are leading to changes in the global environment that could have profound consequences.
Scientific research is the means for developing an understanding of these changes and their causes. Scientific evidence accumulated over the last few decades indicates that the rate, magnitude, and extent of environmental changes are the result of a complex interplay among a number of natural and human-related systems. Understanding what is occurring and what will occur in the future thus requires an understanding of all of the components of what has come to be called the Earth system.
The components of the Earth system include the atmosphere, the oceans, the continents, the biological life, and the regions of ice and snow. The state of these components is controlled by "forcing agents" that lead to changes in their state, thus to changes in the overall Earth system. The components are linked by an amazing diversity of physical, chemical, and biological processes that transmit change throughout the system. Most of these are natural processes, but some - for example, changes in land use that result in land- cover changes and the production of greenhouse gases - are strongly influenced by human activities.
Changes in any single element of the Earth's environment cannot be understood by studying that component alone. For example, the Earth's climate involves not only temperature, winds, and clouds in the atmosphere, but also the interactive effects of ocean currents and surface temperatures; the biosphere (living organisms and the environment that supports them); atmospheric composition; the Earth's orbital characteristics; the reflective properties of the planet; the distribution of water between the atmosphere, hydrosphere (oceans and freshwater), and cryosphere (snow and ice); and numerous other factors. Similarly, other important occurrences, such as changes in the productivity of the oceans or land surface or the incidence of volcanic eruptions, are linked to a variety of interactive phenomena.
Given the complexity of the Earth system and the many feedbacks among its components, understanding and predicting climatic and environmental change is an exceedingly difficult challenge. For example, human-induced increases in atmospheric carbon dioxide (CO2) and other trace gas concentrations are major forcing factors for climate change. However, because CO2 is the primary raw material for photosynthesis, an increased CO2 concentration is also likely to influence the character, extent, and distribution of the Earth's vegetative cover. This, in turn, will affect solar and terrestrial radiation (processes of energy transfer), the biogeochemical budget (distribution and circulation of chemicals, such as carbon and nitrogen, between the Earth's crust and the cells of living organisms), and the hydrological budget (distribution and circulation of water). These changes can alter climate in ways that can serve either to enhance or ameliorate the effects of the original CO2 forcing. Such complexities make prediction anything but straightforward.
Over the past decade, the development of scientific insight and research capabilities has greatly advanced the understanding of global change. The growing understanding - among scientists and non-scientists alike - that the current and future state of the Earth system is inexorably linked to human activities, and the growing societal concern about the implications of global environmental change, underscore the need for and importance of these scientific efforts. The results of research supported by the USGCRP are providing both quantitative and qualitative information about important questions involving the Earth system (including humans), how it is changing, and the implications of global environmental change for society.
The USGCRP was established by President Reagan and included as a Presidential Initiative in the FY90 budget by President Bush as a high-priority research effort:
Congress codified the USGCRP in the Global Change Research Act of 1990, in order to provide for the following:
The Global Change Research Act defines global change as "changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life."
This mandate for the USGCRP makes it clear that the program is to have a broad scope and consider the full set of issues dealing with actual and potential global environmental change. This broad approach recognizes the profound economic, social, and ecological implications of global changes and the need for U.S. leadership in this area.
Since its inception, the USGCRP has been directed toward strengthening research on key scientific issues, and has fostered much improved insight into the processes and interactions of the Earth system. The results of research supported by the USGCRP play an important role in international scientific assessments, including assessments of climate change and stratospheric ozone depletion. The USGCRP research results provide the scientific information base that underpins consideration of possible response strategies, but the USGCRP does not recommend policies on global change issues, nor does it include support for research and development of energy technologies, development of mitigation strategies, or the Climate Change Action Plan.
The underlying premise of the USGCRP is that appropriate use of the Earth for human habitation and survival is inextricably linked to an improved understanding of the systems that are undergoing change in response to natural and human-influenced processes. Presidents Bush and Clinton, and Congress, have supported the USGCRP as a high priority in the national scientific research agenda.
For FY97, the President's budget requests appropriations of $1.73 billion for the USGCRP. See Appendix A for a description of the overall USGCRP budget request. See Appendix B for a description of global change research budget requests for individual USGCRP-participating agencies.
The Subcommittee on Global Change Research (SGCR) of the Committee on Environment and Natural Resources (CENR), a component of the National Science and Technology Council (NSTC), provides overall direction and executive oversight of the USGCRP. Within this framework, agencies manage and coordinate Federally supported scientific research on global change. The Global Change Research Act specifies a minimum of 14 Federal agencies as well as planning and oversight offices of the Executive Office of the President to be represented in the oversight of global change research.
In FY97, 10 agencies will be supporting research as part of the USGCRP. A few of the agencies support research on a broad range of issues, while others have a more specialized focus. Programmatic contributions are closely matched to agency missions and areas of expertise.
[see Subcommittee on Global Change Research]
Global environmental issues are very complex and require a wide range of expertise. Close cooperation among agencies is required because of the wide range of challenges to be addressed, the differing interests and capabilities of each agency, and the need to make the most effective use of available budgetary resources to implement a strong research program.
Thus, for example, NASA leads efforts relating to satellite observations of the Earth as well as research to interpret and understand these observations; NOAA leads efforts relating to its interests in improving predictions of atmospheric and oceanic behavior; DOE focuses on research to predict the behavior of the global climate system on decadal to centennial time scales in response to changes in atmospheric composition, and to evaluate the contribution of energy-based emissions to climate change; NSF focuses on broadly based fundamental research to improve understanding of the Earth system; USDA focuses on the roles of and consequences for agriculture, food production, and forests of global-scale environmental change; NIH focuses on potential health-related impacts; DOI focuses on climate system history and impacts on water resources and public lands; EPA focuses on ecosystem and societal impacts of global change; DoD focuses on prediction of seasonal climate anomalies affecting its national security operations; and the Smithsonian Institution focuses on improving knowledge of the natural processes involved in global change.
It is crucial to have a sound, widely accepted, integrated scientific approach to investigating global change. The USGCRP presented a detailed scientific research plan in October 1990.4 This plan, updated annually in Our Changing Planet, which is submitted to Congress each year as a supplement to the President's budget, has served as an important guide to research efforts over the past several years. The research programs that have been developed since this plan was published emphasize the search for a better predictive understanding of the world around us through increased interagency, bilateral, and multilateral cooperation.
The USGCRP is preparing a new multi-year research plan that is responsive to the advancement of scientific understanding, the recommendations of the National Academy of Sciences in its 1995/96 review of the program, and the Global Change Research Act. Concurrently, the USGCRP has drafted an updated statement of the overall goal of the program.
In response to requests from the Subcommittee on Global Change Research and from Congressional committee chairs in both the House and the Senate, the National Academy of Sciences asked its operational arm, the National Research Council, to initiate a major program review of the USGCRP; the first phase was begun in the summer of 1995. This review was undertaken by the NRC Board on Sustainable Development and its Committee on Global Change Research, which convened a joint 2-week meeting in July 1995, and continued their deliberations at meetings in November 1995 and March 1996.
[see National Research Council 1995 Review Recommendations on the USGCRP]
The NRC issued an interim report in September 1995, entitled A Review of the U.S. Global Change Research Program and NASA's Mission to Planet Earth/Earth Observing System. In this first phase, the review considered the scientific foundations and progress to date of the USGCRP, and the role of the Earth Observing System and the EOS Data and Information System (EOSDIS) in meeting the USGCRP's need for global observations.
Since receiving the NRC interim review in September 1995, the SGCR and the USGCRP agencies have been moving aggressively to respond to the NRC recommendations on program integration and strategic research directions. The SGCR has presented its plans for streamlining its interagency structure to the NRC for consideration and is moving to ensure a stronger set of contacts with the scientific community through the NRC. Interagency teams have been formed to draft focused components of a new USGCRP multi-year plan, which is being prepared for review and approval during 1996.
With the President's FY97 budget request, NASA will be able to sustain the planned launch schedule of MTPE satellites. The overall EOS program has been restructured to include opportunities for small satellite missions to both initiate new science studies and to test new instrument technologies. Planning for streamlining and re configuring EOSDIS is underway.
The accompanying figure presents a schematic diagram of the USGCRP research framework. This framework is designed to strengthen the integration of scientific activities and to aid in achieving strategic direction for future research program efforts.
[see USGCRP Research Framework diagram]
The top row of the diagram indicates the major issue-oriented thrusts of the USGCRP. These focused research efforts on key global change environmental science issues depend on a set of integrating activities, including observations and data management, pr ocess studies, predictive modeling, environmental and human consequences research, and support for assessments to provide a scientific underpinning for societal decision making as appropriate to each issue.
These activities are represented by the supporting layers in the diagram, which define the activities and perspectives central to program integration. These integrating activities and perspectives contribute in varying ways to all of the program thrusts on key environmental science issues. In addition, the diagram indicates ongoing program responsibilities pertaining to international research cooperation and to global change education and communication.
Within each of these areas, the USGCRP emphasizes the following:
The SGCR has program direction and oversight responsibility for ensuring integration and balance in the efforts of these panels.
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