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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.
Support for this project was provided by the U.S. Global Change Research Program, the U.S. Environmental Protection Agency, and the National Aeronautics and Space Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the sponsors.
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Cover: The cover image shows the distribution of atmospheric carbon monoxide over the Western Hemisphere (at approx. 880hPa) simulated at Harvard University using GEOS-CHEM, a global three-dimensional model of tropospheric chemistry driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS) of the NASA Data Assimilation Office. Note that the color-scale of the image has been altered for use on the report cover. The original image, along with a variety of other GEOS-CHEM simulation results are available online at: http://www-as.harvard.edu/chemistry/trop/
Copyright 2001 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
THE NATIONAL ACADEMIES
National Academy of Sciences
National Academy of Engineering
Institute of Medicine
National Research Council
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.
COMMITTEEON ATMOSPHERIC CHEMISTRY
MARIO M. MOLINA (Chair), Massachusetts Institute of Technology, Cambridge, MA
JOHN H. SEINFELD (Vice-Chair), California Institute of Technology, Pasadena, CA
CYNTHIA S. ATHERTON, University of California, Lawrence Livermore National Laboratory, Livermore, CA
KELLY CHANCE, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA
KENNETH DEMERJIAN, University at Albany/SUNY, Albany, NY
DAVID W. FAHEY, NOAA Aeronomy Laboratory, Boulder, CO
SONIA KREIDENWEIS, Colorado State University, Fort Collins, CO
DANIEL A. LASHOF, Natural Resources Defense Council, Washington, DC
HIRAM LEVY II, NOAA Geophysical Fluid Dynamics Laboratory, Princeton University, Princeton, NJ
JOSE M. RODRIGUEZ, University of Miami, FL
CHRISTINE S. SLOANE, General Motors Corporation, Detroit, MI
RAY F. WEISS, University of California-San Diego, Scripps Institution of Oceanography, La Jolla, CA
LAURIE S. GELLER, Study Director
TENECIA A. BROWN, Senior Program Assistant
MARIA WITMER RICH, NRC Research Intern
BOARD ON ATMOSPHERIC SCIENCES AND CLIMATE
ERIC J. BARRON (Chair), Pennsylvania State University, University Park
SUSAN K. AVERY, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder
HOWARD B. BLUESTEIN, University of Oklahoma, Norman
STEVEN F. CLIFFORD, National Oceanic and Atmospheric Administration, Boulder, Colorado
GEORGE L. FREDERICK, Radian Electronic Systems, Austin, Texas
MARVIN A. GELLER, State University of New York, Stony Brook
CHARLES E. KOLB, Aerodyne Research, Inc., Billerica, Massachusetts
JUDITH L. LEAN, Naval Research Laboratory, Washington, D.C.
ROGER A. PIELKE, JR., National Center for Atmospheric Research, Boulder, Colorado
MICHAEL J. PRATHER, University of California, Irvine
ROBERT T. RYAN, WRC-TV, Washington, D.C.
MARK R. SCHOEBERL, NASA Goddard Space Flight Center, Greenbelt, Maryland
JOANNE SIMPSON, NASA Goddard Space Flight Center, Greenbelt, Maryland
THOMAS F. TASCIONE, Sterling Software, Inc., Bellevue, Nebraska
ROBERT A. WELLER, Woods Hole Oceanographic Institution, Massachusetts
ERIC F. WOOD, Princeton University, New Jersey
Ex Officio Members
DONALD S. BURKE, Johns Hopkins University, Baltimore, Maryland
DARA ENTEKHABI, Massachusetts Institute of Technology, Cambridge
MARIO MOLINA, Massachusetts Institute of Technology, Cambridge
EUGENE M. RASMUSSON, University of Maryland, College Park
EDWARD S. SARACHIK, University of Washington, Seattle
ELBERT W. (JOE) FRIDAY, JR., Director
LAURIE S. GELLER, Program Officer
ALEXANDRA ISERN, Program Officer
PETER A. SCHULTZ, Program Officer
VAUGHAN C. TUREKIAN, Program Officer
DIANE L. GUSTAFSON, Administrative Assistant
ROBIN MORRIS, Financial Associate
TENECIA A. BROWN, Project Assistant
CARTER W. FORD, Project Assistant
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 wish to thank the following individuals for their participation in the review of this report:
Judith Chow, Desert Research Institute, Reno, Nevada
Charles Kolb, Aerodyne Research Inc., Cambridge, Massachusetts
Robert Serafin, National Center for Atmospheric Research, Boulder, Colorado
Susan Solomon, National Oceanic and Atmospheric Administration, Boulder, Colorado
Nien Dak Sze, Atmospheric and Environmental Research Inc., Cambridge, Massachusetts
Richard Turco, University of California, Los Angeles
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of
this report was overseen by F. Sherwood Rowland (University of California, Irvine) appointed by the NRC's Report Review Committee, who were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.
The National Research Council's Committee on Atmospheric Chemistry (NRC/CAC) was established to serve as a focal point for NRC activities on issues related to atmospheric chemical change and its impacts on air quality, climate, stratospheric ozone depletion, and other related issues. The committee consists of 12 members with expertise covering the areas of tropospheric and stratospheric chemistry; urban/regional air pollution; modeling of climate, chemistry, and atmospheric dynamics; in situ and remote sensing observational systems; and interfaces of science and public policy.
This CAC study was motivated by a concern that, in the coming decades, dramatic increases in global population and urbanization levels, as well as changes in global climate, may significantly affect air quality over large regions of the globe. The charge to the committee was to examine the linkages among regional/ global changes in atmospheric composition, climate change, and air quality. In particular, their task was to:
review projections of how future global industrialization, urbanization, and other human activities could alter regional and global atmospheric composition and chemistry over the next century;
discuss how these global chemical changes could affect atmospheric radiative forcing and impact U.S. air quality;
describe the gaps in scientific understanding that currently impede our ability to accurately assess such changes;
identify the observational data that are most critical for detecting and documenting these chemical changes, characterize the capacity of current
observational systems to collect such data, and suggest ways that these systems can be enhanced or better integrated to provide the necessary observations;
identify any other research needs related to this issue and, where appropriate, discuss what types of institutional arrangements (on both the national and international level) would be most effective for carrying out this work.
As the title of the report implies, the committee determined that a top priority in the study of global air quality change is the need to strengthen our capacity for sustaining long-term observations of atmospheric composition. However, the committee did not attempt to make highly detailed recommendations about specific observations that should be made (for instance, by suggesting locations and frequencies of measurements for particular chemical species). Determining these types of details is a research challenge requiring in-depth analyses that are beyond the committee's scope. Similarly, this report does not provide a comprehensive literature review on all the topics of relevance to this study; rather, the publications cited in the report were chosen only as useful examples or sources of further information for the reader.
In developing the goals of this study, and in formulating their conclusions and recommendations, the CAC members sought input from a wide variety of sources including members of the NRC Board on Atmospheric Sciences and Climate; representatives of federal agencies including the National Aeronautics and Space Administration, the U.S. Environmental Protection Agency, the National Oceanic and Atmospheric Administration, the National Science Foundation, and the Department of Energy; leaders of international scientific organizations including the Intergovernmental Panel on Climate Change, the International Global Atmospheric Chemistry project, the organization on Stratospheric Processes and their Role in Climate; and numerous individual scientists who are involved in research related to this topic. The committee extends its gratitude to all of the individuals who participated in the CAC meetings and who provided background information for this study. The committee is also grateful to the NRC staff who provided invaluable input for developing this study and preparing this report. This project was supported by the U.S. Global Change Research Program, the National Aeronautics and Space Administration, and the U.S. Environmental Protection Agency.