THE NATIONAL ACADEMIES PRESS This PDF is available at http://nap.edu/11676 SHARE Surface Temperature Reconstructions for the Last 2,000 Years (2006) DETAILS 160 pages | 7 x 10 | PAPERBACK ISBN 978-0-309-10225-4 | DOI 10.17226/11676 CONTRIBUTORS GET THIS BOOK Committee on Surface Temperature Reconstructions for the Last 2,000 Years; Board on Atmospheric Sciences and Climate; Division on Earth and Life Studies; National Research Council FIND RELATED TITLES SUGGESTED CITATION National Research Council 2006. Surface Temperature Reconstructions for the Last 2,000 Years. Washington, DC: The National Academies Press. https://doi.org/10.17226/11676. 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Surface Temperature Reconstructions for the Last 2,000 Years THE NATIONAL ACADEMIES PRESS 500 Fifth Street NW Washington, DC 20001 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. International Standard Book Number-10: 0-309-10225-1 (Book) International Standard Book Number-13: 978-0-309-10225-4 (Book) International Standard Book Number-10: 0-309-66144-7 (PDF) International Standard Book Number-13: 978-0-309-66144-7 (PDF) Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, D.C. 20055; (800) 624-6242 or (202)334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu. Copyright 2006 by the National Academy of Sciences. All rights reserved. Printed in the United States of America Copyright National Academy of Sciences. All rights reserved. Surface Temperature Reconstructions for the Last 2,000 Years 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. Ralph J. Cicerone 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 spon- sors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. 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 pertain- ing 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. Harvey V. Fineberg 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. Ralph J. Cicerone and Dr. Wm. A. Wulf are chair and vice chair, respectively, of the National Research Council. www.national-academies.org Copyright National Academy of Sciences. All rights reserved. Surface Temperature Reconstructions for the Last 2,000 Years Copyright National Academy of Sciences. All rights reserved. Surface Temperature Reconstructions for the Last 2,000 Years COMMITTEE ON SURFACE TEMPERATURE RECONSTRUCTIONS FOR THE LAST 2,000 YEARS GERALD R. NORTH (Chair), Texas A&M University, College Station FRANCO BIONDI, University of Nevada, Reno PETER BLOOMFIELD, North Carolina State University, Raleigh JOHN R. CHRISTY, University of Alabama, Huntsville KURT M. CUFFEY, University of California, Berkeley ROBERT E. DICKINSON, Georgia Institute of Technology, Atlanta ELLEN R.M. DRUFFEL, University of California, Irvine DOUGLAS NYCHKA, National Center for Atmospheric Research, Boulder, Colorado BETTE OTTO-BLIESNER, National Center for Atmospheric Research, Boulder, Colorado NEIL ROBERTS, University of Plymouth, United Kingdom KARL K. TUREKIAN, Yale University, New Haven, Connecticut JOHN M. WALLACE, University of Washington, Seattle NRC Staff IAN KRAUCUNAS, Study Director CHRIS ELFRING, Board Director AMANDA STAUDT, Senior Program Officer ELIZABETH A. GALINIS, Research Associate LEAH PROBST, Research Associate DIANE GUSTAFSON, Administrative Coordinator NORMAN GROSSBLATT, Senior Editor v Copyright National Academy of Sciences. All rights reserved. Surface Temperature Reconstructions for the Last 2,000 Years BOARD ON ATMOSPHERIC SCIENCES AND CLIMATE ROBERT J. SERAFIN (Chair), National Center for Atmospheric Research, Boulder, Colorado M. JOAN ALEXANDER, NorthWest Research Associates/CORA, Boulder, Colorado FREDERICK R. ANDERSON, McKenna Long & Aldridge LLP, Washington, D.C. MICHAEL L. BENDER, Princeton University, New Jersey ROSINA M. BIERBAUM, University of Michigan, Ann Arbor MARY ANNE CARROLL, University of Michigan, Ann Arbor CAROL ANNE CLAYSON, Florida State University, Tallahassee WALTER F. DABBERDT, Vaisala Inc., Boulder, Colorado KERRY A. EMANUEL, Massachusetts Institute of Technology, Cambridge DENNIS L. HARTMANN, University of Washington, Seattle PETER R. LEAVITT, Weather Information Inc., Newton, Massachusetts JENNIFER A. LOGAN, Harvard University, Cambridge, Massachusetts VERNON R. MORRIS, Howard University, Washington, D.C. F. SHERWOOD ROWLAND, University of California, Irvine THOMAS H. VONDER HAAR, Colorado State University/CIRA, Fort Collins ROGER M. WAKIMOTO, National Center for Atmospheric Research, Boulder, Colorado Ex Officio Members ANTONIO J. BUSALACCHI, JR., University of Maryland, College Park ERIC F. WOOD, Princeton University, New Jersey NRC Staff CHRIS ELFRING, Director PAUL CUTLER, Senior Program Officer AMANDA STAUDT, Senior Program Officer MARIA UHLE, Program Officer IAN KRAUCUNAS, Associate Program Officer CLAUDIA MENGELT, Associate Program Officer ELIZABETH A. GALINIS, Research Associate LEAH PROBST, Research Associate ROB GREENWAY, Senior Program Assistant DIANE GUSTAFSON, Administrative Coordinator ANDREAS SOHRE, Financial Associate vi Copyright National Academy of Sciences. All rights reserved. Surface Temperature Reconstructions for the Last 2,000 Years Foreword Our understanding of climate and how it has varied over time is advancing rapidly as new data are acquired and new investigative instruments and methods are employed. Thus in 2005, I suggested to the U.S. Congress that the National Research Council (NRC) could help answer questions about the data and methods that have been used in constructing records of Earth’s surface temperatures from times when there were no scientific instru- ments, using proxy indicators. How has temperature varied over the last 2,000 years? How certain is the answer to this question? Subsequently, this study was requested by Representative Sherwood Boehlert, chairman of the Committee on Science, U.S. House of Representatives. Chairman Boehlert asked for a clear and concise report in a relatively short period of time, and the NRC agreed to under- take the study quickly. An ad hoc committee was formed, with the group carefully com- posed to include the breadth and depth of expertise and perspectives needed to analyze all aspects of how surface temperatures are estimated and interpreted and to comment generally on climate science. The NRC asked the committee to summarize current