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For sale by the Books and Open-File Reports Section, U.S. Geological Survey Federal Center, Box 25425, Denver, CO 80225

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A Global Perspective on the Role of the Earth Sciences

By Dallas L. Peck
Director, U.S. Geological Survey

eflecting on the events of the 1988 fiscal year, I
recall that it began with a troubling reminder to

this agency and to the Nation as to how vulnerable we are to the capricious acts of nature—the October 1, 1987, earthquake that was centered near Whittier, Calif., in the greater Los Angeles metropolitan area. While the magnitude 5.9 tremor was not a truly large earthquake in a seismological sense, the impacts and effects of that shock were a striking reminder that we are not in control of the Earth, nor do we fully understand the geologic forces and processes that affect it. The challenge of understanding those forces is what makes earth science such an exciting field of research. As the Nation's principal earth science agency, the U.S. Geological Survey is charged with advancing understanding of the earth system, interpreting the significance of scientific findings, and communicating those findings to the policymakers and managers who need the information.

We must remind ourselves that the forces and processes at work on Earth are not mindful of calendars and new fiscal years, nor do they fit nicely within political boundaries. Whatever the season, administration, or political climate, the Earth functions on its own timeclock, with its own independent controls. In that independence of the Earth lies a special challenge for the earth scientist. We must be scientists who view the Earth as a whole and yet are able to relate that view to our particular human aspirations and boundaries; and we must also be able to study regions and smaller areas in great detail and then extrapolate that knowledge to a much broader, sometimes global, perspective.

I have had a unique opportunity during this past year to put that challenge into play. In what I see as an extraordinary companion role to that of USGS Director, I have had the privilege of serving as the Chairman of the Committee on Earth Sciences within the Federal Coordinating Council on Science, Engineering, and Technology, under the auspices of the President's Science Advisor.

That is quite a bureaucratic mouthful, but the chairmanship of the Committee has allowed me, and encouraged the USGS, to enter into a special arena in which we not only can but should play an important role. That special area is the emerging science of global change. By global change I refer to both short-term

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...we must concentrate our efforts on viewing the

Earth as a complex, dynamic, and interactive

global system.

and long-term changes and processes of the Earth's interactive spheres: the lithosphere, the Earth's surface and near surface; the hydrosphere, the world's freshwater and oceans; the atmosphere, the source of life-sustaining oxygen, but also, all too often, the destination of the results of human activities; the cryosphere, the cold reaches of the Earth's two poles and its high mountains; and the biosphere, the life-plant, animal, and human-of the Earth.

The implications and impacts of global change - what can already be documented and what can be deciphered from the geologic record-are many, including climate change, sea-level rise and fall, expansion and recession of enormous ice sheets, changes in plant and animal life, and volcanic eruptions. Clearly there is much to understand and much to do. The major charge to the Committee on Earth Sciences is to increase “the overall effectiveness and productivity of Federal research and development efforts directed toward an understanding of the Earth as a global system.” That charge reinforces my belief that we must concentrate our efforts on viewing the Earth as a complex, dynamic, and interactive global system. Expertise from many different organizations and from a wide range of interrelated scientific disciplines is required to address the global system-meteorology, oceanography, hydrology, geology, biology, chemistry, and physics, to name only a few.

The USGS has much to contribute to the understanding of the Earth's system and natural and human-caused changes in it; indeed most of our activities could be interpreted to relate to global change. Our long history of scientific investigation has given us experience and abilities that will be important for monitoring aspects of global change, determining past changes and the causes and consequences of these changes, understanding

some of the physical and chemical processes that are key to predicting global change, and evaluating possible management strategies for responding to changes affecting the land and hydrologic systems. The USGS also has long experience in managing large data bases such as those necessary to evaluate global processes and changes. This expertise is particularly appropriate for addressing a current major global-change concern, global warming.

Using large numerical models of the energy and mass balance of the atmosphere, scientists have predicted global warming of 2–5 degrees Celsius over the next half-century, assuming a doubling of atmospheric carbon dioxide concentrations due in part to emissions from the combustion of fossil fuels. These models have large uncertainties and differences, and they do not represent well some of the key components of the global system; however, they all indicate that warming would occur first and be greatest in magnitude at the poles. The USGS has a long history of conducting polar studies and glacier monitoring that could provide an early indication of global warming. Earlier this year the USGS published the first volume of a planned series of 11 atlases on the world's major glaciers that will provide an excellent foundation for monitoring such changes.

The USGS has been involved in numerous investigations of marine and terrestrial sediments, lake and cave deposits, ice, tree rings, and fossils that provide information on past climatic conditions. This information will be critical for determining natural short-term and long-term climatic variability. An article in this yearbook summarizes investigations on a sediment core from an ancient lake in California, which documented regional climatic changes for the past 3 million years.

Paleoclimate studies also can provide information on possible causes of climate change and environmental responses to these changes. While the general circulation models predict that climate changes will be accompanied by dramatic changes in the hydrologic system, current models do not represent the whole hydrologic cycle in sufficient detail to provide useful information on the significance of hydrologic changes to the environment. The

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