Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page R1
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade GLOBAL ENVIRONMENTAL CHANGE Research Pathways for the Next Decade Committee on Global Change Research Board on Sustainable Development Policy Division National Research Council NATIONAL ACADEMY PRESS Washington, D.C.
OCR for page R2
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade NATIONAL ACADEMY PRESS 2101 Constitution Avenue, N.W. Washington, D.C. 20418 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This study was supported by Contract Nos. 50-DKNA-5-00015 and 50-DNKA-7-90052 between the National Academy of Sciences and the National Oceanic and Atmospheric Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project. Library of Congress Cataloging-in-Publication Data Global environmental change : research pathways for the next decade / Committee on Global Change Research, Board on Sustainable Development, Policy Division, National Research Council. p. cm. Includes bibliographical references and index. ISBN 0-309-06420-1 (hardcover : alk. paper) 1. Global environmental change. 2. U.S. Global Change Research Program. 3. Climatic changes—Research—United States. 4. Global warming—Research—United States. 5. Greenhouse effect, Atmospheric —Research—United States. I. National Research Council (U.S.). Committee on Global Change Research. GE150 .G56 1999 363.738′74′072073—dc21 99-6463 Additional copies of this report are available from the National Academy Press, 2101 Constitution Avenue, N.W., Lockbox 285, Washington, D.C. 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); http://www.nap.edu Printed in the United States of America Copyright 1999 by the National Academy of Sciences. All rights reserved. Cover image: Face of the Earth, ARC Science Simulations, Copyright 1996-1998, www.arcinc.com
OCR for page R3
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade COMMITTEE ON GLOBAL CHANGE RESEARCH BERRIEN MOORE III (Chairman), University of New Hampshire, Durham JAMES G. ANDERSON, Harvard University, Cambridge, Massachusetts GREGORY H. CANAVAN, Los Alamos National Laboratory, Los Alamos, New Mexico ROBERT COSTANZA, University of Maryland, Solomons W. LAWRENCE GATES, University of California, Livermore PRISCILLA C. GREW, University of Nebraska, Lincoln MARGARET S. LEINEN, University of Rhode Island, Narragansett PAUL A. MAYEWSKI, University of New Hampshire, Durham JAMES J. MCCARTHY, Harvard University, Cambridge, Massachusetts S. ICHTIAQUE RASOOL, University of New Hampshire, Durham EDWARD S. SARACHIK, University of Washington, Seattle DAVID S. SCHIMEL, University Center for Atmospheric Research, Boulder, Colorado W. JAMES SHUTTLEWORTH, University of Arizona, Tucson KARL K. TUREKIAN, Yale University, New Haven, Connecticut PETER M. VITOUSEK, Stanford University, Stanford, California Ex-Officio Members Liaison Members, Board on Sustainable Development EDWARD A. FRIEMAN, Scripps Institution of Oceanography, Chairman, Board on Sustainable Development ROBERT A. FROSCH, Harvard University, Cambridge, Massachusetts Co-chairman, Board on Atmospheric Sciences and Climate ERIC J. BARRON, Pennsylvania State University Chairman, Committee on Geophysical and Environmental Data FRANCIS P. BRETHERTON, University of Wisconsin, Madison Chairman, Ocean Studies Board KENNETH BRINK, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
OCR for page R4
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade Chairman, Committee on Atmospheric Chemistry WILLIAM L. CHAMEIDES, Georgia Institute of Technology Chairman, Board on Atmospheric Sciences and Climate JOHN A. DUTTON, Pennsylvania State University Chairman, Climate Research Committee THOMAS R. KARL, National Climatic Data Center, Asheville, North Carolina Chairman, Committee on the Human Dimensions of Global Change DIANA M. LIVERMAN, University of Arizona, Tucson Chairman, Panel on Climate Variability on Decade-to-Century Timescales DOUG MARTINSON, Columbia University, Palisades, New York Chairman, Global Energy and Water Cycle Experiment Panel SOROOSH SOROOSHIAN, University of Arizona, Tucson Chairman, Global Ocean-Atmosphere-Land System PETER WEBSTER, University of Colorado, Boulder NRC Staff SHERBURNE B. ABBOTT, Executive Director DAVID M. GOODRICH, Project Director (ending January 16, 1998) SYLVIA A. EDGERTON, Senior Research Fellow (April 8, 1998, to April 9, 1999) LAURA SIGMAN, Research Associate (beginning February 17, 1998) LESLIE McCANT, Project Assistant (beginning January 22, 1999)
OCR for page R5
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade BOARD ON SUSTAINABLE DEVELOPMENT EDWARD A. FRIEMAN (Chairman), University of California, La Jolla ROBERT W. KATES (Vice-Chairman), Independent Scholar LOURDES ARIZPE, UNESCO, Paris, France JOHN BONGAARTS, The Population Council, New York, New York RALPH J. CICERONE, University of California, Irvine WILLIAM C. CLARK, Harvard University, Cambridge, Massachusetts ROBERT A. FROSCH, Harvard University, Cambridge, Massachusetts MALCOM GILLIS, Rice University, Houston, Texas RICHARD R. HARWOOD, Michigan State University, East Lansing PHILIP J. LANDRIGAN, Mount Sinai School of Medicine, New York, New York KAI N. LEE, Williams College, Williamstown, Massachusetts JERRY D. MAHLMAN, Princeton University, Princeton, New Jersey RICHARD J. MAHONEY, Washington University, St. Louis, Missouri PAMELA A. MATSON, Stanford University, Stanford, California WILLIAM J. MERRELL, H. John Heinz III Center, Washington, D.C. G. WILLIAM MILLER, G. William Miller & Company, Inc., Washington, D.C. M. GRANGER MORGAN, Carnegie-Mellon University, Pittsburgh, Pennsylvania PAUL RASKIN, Tellus Institute, Boston, Massachusetts JOHN B. ROBINSON, University of British Columbia, Vancouver, Canada VERNON W. RUTTAN, University of Minnesota, St. Paul THOMAS C. SCHELLING, University of Maryland, College Park MARVALEE H. WAKE, University of California, Berkeley WARREN WASHINGTON, National Center for Atmospheric Research, Boulder, Colorado M. GORDON WOLMAN, Johns Hopkins University, Baltimore, Maryland Ex-Officio Member Chairman, Committee on Global Change Research BERRIEN MOORE III, University of New Hampshire, Durham NRC Staff SHERBURNE B. ABBOTT, Executive Director LAURA SIGMAN, Research Associate (beginning February 17, 1998) LESLIE McCANT, Project Assistant (beginning January 22, 1999)
OCR for page R6
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and vice-chairman, respectively, of the National Research Council.
OCR for page R7
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade Acknowledgment of Reviewers This report has been reviewed by individuals chosen for their diverse perspectives and technical expertise in accordance with procedures approved by the National Research Council's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the authors and the NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The content of the review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We thank the following individuals for their participation in the review of this report: Ian Burton, Environmental Adaptation Research Group, Downsview, Canada Antony J. Broccoli, Princeton University, Princeton, New Jersey Radford Byerly, Roberts Institute, Boulder, Colorado Robert A. Frosch, Harvard University, Cambridge, Massachusetts Richard M. Goody, Harvard University, Cambridge, Massachusetts John Harte, University of California, Berkeley Dennis L. Hartmann, University of Washington, Seattle Donald F. Hornig, Harvard School of Public Health, Cambridge, Massachusetts Charles F. Kennel, Scripps Institution of Oceanography, La Jolla, California Charles E. Kolb, Aerodyne Research, Inc., Billerica, Massachusetts John E. Kutzbach, University of Wisconsin, Madison Harry F. Lins, U.S. Geological Survey, Reston, Virginia Jacques-Louis Lions, College de France, Paris, France Walter C. Oechel, San Diego State University, San Diego, California
OCR for page R8
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade Jagadish Shukla, Institute of Global Environment & Society, Calverton, Maryland Richard Chapin James Somerville, Scripps Institution of Oceanography, La Jolla, California Eugene Z. Stakhiv, U.S. Army Corps of Engineers, Washington, D.C. Billie L. Turner, Clark University, Worchester, Massachusetts While the individuals listed above provided many constructive comments and suggestions, responsibility for the final content of this report rests solely with the authoring committee and the NRC.
OCR for page R9
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade Preface In the coming century a human population perhaps twice as large as today's will have to navigate a sustainable path through the ever-changing landscape of this small planet. Knowledge gleaned by science will be its best beacon and provide its soundest navigational chart. Science itself faces its own navigational challenges, as questions of growing complexity and richness abound while financial resources are limited. Scientists confront not only these research obstacles but also the urgent call from politicians and policy makers who seek guidance in reaching major decisions. As this report was being prepared, for example, representatives of many nations gathered in Kyoto, Japan, to forge an agreement on goals to cut greenhouse gas emissions. Such agreements set environmental goals, which will clearly affect scientific priorities as well as economic paths in the coming decade. Thus, science needs its own clear framework through which to focus its energies. This intellectual framework is required to hone questions that need immediate attention, to separate the vital from the interesting, and to preserve basic research for discovery of the unexpected. In this report the Committee on Global Change Research (CGCR) provides guidance on such a framework by clarifying especially promising pathways for the planning of future U.S. research on global environmental change. An overview document was released by the committee in 1998 that summarized the background, findings, and recommendations of the report. The foundation of the report's recommendations includes the accumulated knowledge of worldwide scientific research over the past decade and especially that of the U.S. Global Change Research Program (USGCRP). The CGCR was charged with reviewing the current status of the USGCRP with a view toward defining the critical scientific questions in the Program's four
OCR for page R10
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade areas of concentration (seasonal to interannual climate prediction, decadal to centennial climate change, atmospheric chemistry, and terrestrial and marine ecosystems) and with preparing a report that would (1) articulate the central scientific issues posed by global environmental change; (2) state the key scientific questions that must be addressed by the USGCRP; and (3) identify the scientific programs, observational efforts, modeling strategies, and synthesis activities needed to attack these scientific questions. This report traces the scientific roots and programmatic development of the USGCRP, highlighting some of the lessons learned that help point to the most appropriate pathways ahead. The committee calls for a revitalization of the USGCRP, recognizing the need for a more sharply focused scientific strategy and a more coherent programmatic structure and stressing the importance of U.S. leadership in supporting global change research. CGCR's study was undertaken in the context of intense national and international debate about the nature of global environmental change, particularly about the characteristics and potential impacts of climate change. This context is sharpened in several questions raised by the scientific community and the public at large: The science. In light of the U.S. Administration policy and agreements at the Kyoto conference, are not the causes of global change sufficiently clear and therefore should not the USGCRP now concentrate on the science related to mitigation measures? The strategy. What is the appropriate science strategy for resolving uncertainties about global environmental change? Are changes in the current strategy needed? If so, why (what has changed)? What are the crucial differences between any proposed new strategy and the existing strategy, and how do we make a transition from one to the other? The implementation. How can this strategy be implemented in terms of programs? Who will develop the priorities? When will this happen? THE SCIENCE It would be a misinterpretation of U.S. administration policy and agreements at the Kyoto conference to conclude that the causes and characteristics of global change are sufficiently clear that scientific inquiry in this area should be limited to mitigation measures. The agreements at the Kyoto conference are based on a general understanding of some causes and characteristics of global change; however, there remain many scientific uncertainties about important aspects of climate change. If the United States were to abandon or significantly reduce current research programs, the remaining scientific uncertainties would persist. In addition, it would be difficult to have confidence that mitigation measures were addressing the underlying causes. It is true that the forcing terms of global change are being more clearly resolved. For example, the flux of greenhouse gases from industrial activities is
OCR for page R11
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade reasonably well established; the rates and geographical distributions of the mobilization of other chemical compounds also are becoming clearer; and quantitative patterns of land-use change are being elucidated. In addition, significant progress has been made in understanding the lifetimes in the atmosphere of key chemical species such as greenhouse gases. We understand better the chemical and physical interactions that lead to the loss of ozone in the stratosphere and the production of ozone in the troposphere. We have begun to make considerable progress in characterizing patterns of climate variability, with one noted accomplishment being the successful prediction of the most recent El Niño event well in advance of its greatest impacts. And, although on a very limited basis, we have begun to investigate the possible impacts of various climate change scenarios on terrestrial systems by using global models of those systems. A great deal more needs to be understood, however, about global environmental change before we concentrate on “mitigation” science. We do not understand the climate system well enough to clarify the causes and likelihoods of rapid or abrupt climate changes. What does the record from the past reveal in detail about environmental changes? What will be the patterns and modes of human-forced climate changes? What will be the impacts of multiple stresses on systems; in other words, what are the effects on terrestrial ecosystems of changes in the chemistry of the atmosphere, changes in the patterns and intensities of land use, and changes in temperature and rainfall patterns? How will the chemistry of the atmosphere be affected by continuing patterns of human-induced forcing, and how will these changes be affected by climate variability and change? What is the geographical distribution of the sources and sinks of greenhouse gases and how might they change? How will institutions respond to climate and other environmental changes? These are the types of scientific unknowns that require clarification if we are to make sound policy decisions; they are also the questions that must be answered if we are to have a sound foundation for mitigation science. THE STRATEGY The current science strategy was developed in concert with the initial planning of the USGCRP and was based on the view that what was most needed was a broad attack on understanding the Earth as a system. This has been a valuable and intellectually exciting goal, but it has also made the program too diffuse and left it vulnerable. When budgets ceased to expand and began to contract, the Program was not well grounded or well integrated enough to scale back in a logical way. The concept of an Earth system science view of the Program simply could not weather the budget process, which demanded greater specificity and accountability. Moreover, the need for prioritization—which should be one benefit derived from taking a systems viewpoint—has proved to be exceedingly difficult to achieve in practice. Finally, gains in understanding over the past 10 years and changes in the perceived requirements for research (i.e., results are now seen to
OCR for page R12
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade be needed sooner rather than later, and key issues are now in need of resolution) must be recognized in a new strategy. It is, therefore, time to shift course; we are no longer simply building a ship but steering it, too. Given all that we know, these course corrections are necessary to reach our destination, and they will require retrofits in the hardware and navigational aids to improve speed and efficiency. Resources and time are again in finite supply. We must concentrate scientific talents, observational capabilities, and modeling teams. Achieving these goals calls for an alternative strategy—one focused on answering specific, central scientific questions about global change. In fact, our current inability to answer these scientific questions is seriously blocking progress in critical policy development as well as hindering the development of a more systemic view of the planet. Thus, the committee recommends shifting to a scientific strategy of greater focus and sets forth corresponding pathways for research, observations, data systems, and modeling. THE IMPLEMENTATION To implement a new strategy effectively, the USGCRP, working closely with the Office of Management and Budget and the Office of Science and Technology Policy (OSTP), must develop initiatives based directly on the research imperatives, scientific questions, and crosscutting elements described in this report. Recommendations regarding the observational strategy, technological development, data and information systems, and modeling should be explicitly addressed by the USGCRP and OSTP. Establishing the necessary observational systems will be especially challenging. They are likely to be expensive; their components must serve the needs of several different communities and act as a bridge between research and operational lines; and their design must be more robust in the face of changes in financial support. The National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS) polar platforms—initially, EOS AM-1, EOS-PM-1, and EOS CHEM-1 —were conceived as broadly-scoped data-gathering systems. This foundation will be central for needed future missions and will set the baseline for a long-term operational environmental monitoring program that must be built on the operational weather and ozone-observing system of the National Oceanic and Atmospheric Administration, the U.S. Department of Defense, and their international partners. To further the advances of the first three polar platforms, the committee calls for restructuring EOS to obtain data relevant to the Research Imperatives and unanswered Scientific Questions identified in this report, through smaller and more focused missions along the lines of the new Earth System Science Pathfinders. Moreover, some aspects of the observational systems must address three crosscutting scientific themes that are also fundamental to scientific understanding and policy: clarifying the Earth's carbon and water cycles; characterizing climate change on temporal and spatial scales relevant to human activi-
OCR for page R13
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade ties; and elucidating the connections among radiation, dynamics, chemistry, and climate. These achievements will require good in situ observational systems as well as space-based systems. The committee also recommends maintaining existing critical global observations that could be threatened by budget reductions, while designing a more coherent and balanced data and observational strategy for the future to capitalize on technological innovations. As in all science, the task is not complete. Given the recommendations provided in this report, the next task is to review and map the USGCRP activities against the set of Research Imperatives and unanswered Scientific Questions identified here, to help set optimal programmatic priorities. This step should be the next effort of the Committee, its partners in the National Research Council (NRC) complex, and USGCRP agencies. The NRC parent board of this committee, the Board on Sustainable Development (BSD), is seeking to develop its own scientific and intellectual strategy for the transition of our nation and indeed our global society to a sustainable future. This CGCR report will help guide the BSD 's emerging agenda for research on the closely linked issues of energy, environment, and society—an agenda that will be needed to successfully navigate the transition toward sustainability. ACKNOWLEDGMENTS A study like this one, of such broad coverage, would not have been possible without assistance from many notable experts (see Appendix C). In addition to the persons listed earlier, the following NRC committees also contributed to the report: Committee on Human Dimensions of Global Change; Committee on Geophysical and Environmental Data; Climate Research Committee and its panels on the Global Ocean-Atmosphere-Land System, Climate Variability on Decade-to-Century Timescales, and Global Energy and Water Cycle Experiment; Ecosystems Panel; Board on Atmospheric Sciences and Climate; Ocean Studies Board; and Committee on Atmospheric Chemistry. Speaking for both the BSD and the CGCR, we especially want to thank Dave Goodrich for working on the early drafts; John Perry for providing a link between the past and the present; Mark Dafforn, Suzanne Wilhelm, Laura Sigman, and Claudette Baylor-Fleming for editorial work on complicated copy; and Shere Abbott and Sylvia Edgerton for picking up the pieces and completing the project. EDWARD A. FRIEMAN, Chairman Committee on Global Change Research BERRIEN MOORE III, Chairman Board on Sustainable Development
OCR for page R14
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade This page in the original is blank.
OCR for page R15
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade Contents PREFACE ix 1 INTRODUCTION AND BACKGROUND 1 Summary, 1 Background, 2 The Road Ahead, 7 The Pathways Framework, 8 Review of the USGCRP, 10 2 CHANGES TO THE BIOLOGY AND BIOCHEMISTRY OF ECOSYSTEMS 19 Summary, 19 Introduction, 21 Case Studies, 34 A Research Agenda for the Next Decade, 42 Lessons Learned, 56 Research Imperatives, 67 3 CHANGES IN THE CLIMATE SYSTEM ON SEASONAL TO INTERANNUAL TIMESCALES 87 Summary, 87 Introduction, 88 Case Studies, 89 A Research Agenda for the Next Decade, 98 Lessons Learned, 109 Research Imperatives: Priorities for Observations, Modeling, and Theory, 111
OCR for page R16
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade 4 CHANGES IN THE CLIMATE SYSTEM ON DECADE-TO-CENTURY TIMESCALES 127 Summary, 127 Introduction, 129 Case Studies, 130 A Research Agenda for the Next Decade, 140 Lessons Learned, 177 Research Imperatives: Priorities for Observations, Modeling, and Theory, 178 Conclusions, 184 5 CHANGES IN THE CHEMISTRY OF THE ATMOSPHERE 191 Summary, 191 Introduction, 192 Case Studies, 194 A Research Agenda for the Next Decade, 199 Lessons Learned, 206 Research Imperatives: Priorities for Observations, Modeling, and Theory, 209 6 PALEOCLIMATE OVERVIEW 237 Summary, 237 Introduction, 239 Case Studies, 240 Key Scientific Questions and Issues, 268 Lessons Learned, 272 Research Imperatives, 274 7 HUMAN DIMENSIONS OF GLOBAL ENVIRONMENTAL CHANGE 293 Summary, 293 Introduction, 295 Case Studies: Contributions of Human Dimensions Research in Addressing Global Change, 298 Key Scientific Questions, 302 Lessons Learned, 333 Research Imperatives, 337 Conclusion: Key Research Issues for the USGCRP, 357 8 OBSERVATIONS 377 Introduction, 377 Observations Required for the Science Elements of the USGCRP, 379
OCR for page R17
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade A Multipurpose, Multiuse Observing System for the USGCRP: Elements of System Design, 416 Case Studies, 421 Toward a Permanent Observing System, 424 9 PROCESSING AND DISTRIBUTING EARTH OBSERVATIONS AND INFORMATION 435 Introduction, 435 The EOS Data and Information System: Implications for the USGCRP, 435 Moving Toward a New EOS Information System, 441 10 MODELING 445 Introduction, 445 The Terrestrial-Atmosphere Subsystem, 457 The Land-Ocean Subsystem, 464 The Atmosphere-Ocean Subsystem, 473 The Atmospheric Physical-Chemical Subsystem, 487 The Human Linkage to the Earth System, 495 Summary, 497 11 FINDINGS AND RECOMMENDATIONS 517 Research Imperatives and Scientific Questions—Drivers of Observations Research, 517 ANNEX 1 537 ANNEX 2 542 ANNEX 3 544 APPENDIX A 551 APPENDIX B 563 APPENDIX C 569
OCR for page R18
GLOBAL ENVIRONMENTAL CHANGE: Research Pathways for the Next Decade This page in the original is blank.