National Academies Press: OpenBook
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

ATTRIBUTION OF

Extreme Weather Events

IN THE CONTEXT OF

Climate Change

Committee on Extreme Weather Events and Climate Change Attribution

Board on Atmospheric Sciences and Climate

Division on Earth and Life Studies

images

THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

THE NATIONAL ACADEMIES PRESS • 500 Fifth Street, NW • Washington, DC 20001

This study was supported by the David and Lucile Packard Foundation under contract number 2015-63077, the Heising-Simons Foundation under contract number 2015-095, the Litterman Family Foundation, the National Aeronautics and Space Administration under contract number NNX15AW55G, the National Oceanic and Atmospheric Administration under contract number EE-133E-15-SE-1748, and the U.S. Department of Energy under contract number DE-SC0014256, with additional support from the National Academy of Sciences’ Arthur L. Day Fund. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.

International Standard Book Number-13: 978-0-309-38094-2
International Standard Book Number-10: 0-309-38094-4
Library of Congress Control Number: 2016946880
Digital Object Identifier: 10.17226/21852

Additional copies of this report are available for sale from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; Internet, http://www.nap.edu.

Copyright 2016 by the National Academy of Sciences. All rights reserved.

Printed in the United States of America

Cover imagery courtesy of Cameron Beccario, http://earth.nullschool.net.

Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Image

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Ralph J. Cicerone is president.

The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president.

The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president.

The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine.

Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

This page intentionally left blank.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

COMMITTEE ON EXTREME WEATHER EVENTS AND CLIMATE CHANGE ATTRIBUTION

DAVID W. TITLEY (Chair), Pennsylvania State University, University Park

GABRIELE HEGERL, University of Edinburgh, UK

KATHARINE L. JACOBS, University of Arizona, Tucson

PHILIP W. MOTE, Oregon State University, Corvallis

CHRISTOPHER J. PACIOREK, University of California, Berkeley

J. MARSHALL SHEPHERD, University of Georgia, Athens

THEODORE G. SHEPHERD, University of Reading, UK

ADAM H. SOBEL, Columbia University, New York, NY

JOHN WALSH, University of Alaska, Fairbanks

FRANCIS W. ZWIERS, University of Victoria, BC, Canada

National Academies of Sciences, Engineering, and Medicine Staff

KATHERINE THOMAS, Program Officer

LAUREN EVERETT, Program Officer

AMANDA PURCELL, Associate Program Officer

RITA GASKINS, Administrative Coordinator

ERIN MARKOVICH, Program Assistant

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

This page intentionally left blank.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

BOARD ON ATMOSPHERIC SCIENCES AND CLIMATE

A.R. RAVISHANKARA (Chair), Colorado State University, Fort Collins

GERALD A. MEEHL (Vice Chair), National Center for Atmospheric Research, Boulder, CO

LANCE F. BOSART, University at Albany-SUNY, NY

MARK A. CANE, Columbia University, Palisades, NY

SHUYI S. CHEN, University of Miami, FL

HEIDI CULLEN, Climate Central, Princeton, NJ

PAMELA EMCH, Northrop Grumman Aerospace Systems, Redondo Beach, CA

ARLENE FIORE, Columbia University, Palisades, NY

WILLIAM B. GAIL, Global Weather Corporation, Boulder, CO

LISA GODDARD, Columbia University, Palisades, NY

MAURA HAGAN, Utah State University, Logan

TERRI S. HOGUE, Colorado School of Mines, Golden

ANTHONY JANETOS, Boston University, MA

EVERETTE JOSEPH, University at Albany-SUNY, NY

RONALD “NICK” KEENER, JR., Duke Energy Corporation, Charlotte, NC

JOHN R. NORDGREN, The Climate Resilience Fund, Bainbridge Island, WA

JONATHAN OVERPECK, University of Arizona, Tucson

ARISTIDES A.N. PATRINOS, New York University, Brooklyn

S.T. RAO, North Carolina State University, Raleigh

DAVID A. ROBINSON, Rutgers, The State University of New Jersey, Piscataway

CLAUDIA TEBALDI, Climate Central, Princeton, NJ

Ocean Studies Board Liaison

DAVID HALPERN, Jet Propulsion Laboratory, Pasadena, CA

Polar Research Board Liaison

JENNIFER FRANCIS, Rutgers, The State University of New Jersey, Marion, MA

National Academies of Sciences, Engineering, and Medicine Staff

AMANDA STAUDT, Director

EDWARD DUNLEA, Senior Program Officer

LAURIE GELLER, Program Director

KATHERINE THOMAS, Senior Program Officer

LAUREN EVERETT, Program Officer

Page viii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

ALISON MACALADY, Program Officer

AMANDA PURCELL, Associate Program Officer

RITA GASKINS, Administrative Coordinator

ROB GREENWAY, Program Associate

SHELLY FREELAND, Financial Associate

MICHAEL HUDSON, Senior Program Assistant

ERIN MARKOVICH, Program Assistant

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Preface

Extreme weather has affected human society since the beginning of recorded history and certainly long before then. Humans, along with every other living thing on the Earth, have adapted to a certain range of variability in the weather. Although extreme weather can cause loss of life and significant damage to property, people and virtually every other creature have, at least to some degree, adapted to the infrequent extremes they experience within their normal climatic zone.

Humans’ use of fossil fuel since the start of the Industrial Revolution has begun to modify the Earth’s climate in ways that few could have imagined a century ago. The consequences of this change to the climate are seemingly everywhere: average temperatures are rising, precipitation patterns are changing, ice sheets are melting, and sea levels are rising. These changes are affecting the availability and quality of water supplies, how and where food is grown, and even the very fabric of ecosystems on land and in the sea.

Despite these profound changes, climate change and its associated risks still may appear to many people as distant and remote in both time and space. The natural daily and seasonal variability of the weather can mask the changes in the overall climate. Yet, when people experience extreme events that they believe may be occurring with different—usually greater—frequency or with increased intensity, many ask about the connection between climate change and extreme events.

Effective, rigorous, and scientifically defensible analysis of the attribution of extreme weather events to changes in the climate system not only helps satisfy the public’s desire to know but also can provide valuable information about the future risks of such events to emergency managers, regional planners, and policy makers at all levels of government. A solid understanding of extreme weather event attribution in the context of a changing climate can help provide insight into and confidence in the many risk calculations that underpin much of society’s building codes; land, water, health, and food management; insurance; transportation networks; and many additional aspects of daily life.

There are compelling scientific reasons to study extreme weather event attribution as well. The basic physics of how the climate system works and the broad-scale impacts of rapid addition of greenhouse gases on the climate system are well understood. However, much is still to be learned about how the changing climate affects specific

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

weather events. Improved attribution, and ultimately prediction of extreme events, will demonstrate an even more nuanced and sophisticated understanding of the climate system and will enhance scientists’ ability to accurately predict and project future weather and climatic states.

The past decade has seen a remarkable increase in interest and activity in the extreme event attribution field. The first attempt at attributing an extreme weather event to climate change was published in 2004, analyzing the 2003 European summer heat wave that killed tens of thousands of people. In 2012 the American Meteorological Society started to publish a special annual issue of their Bulletin, compiling articles on extreme weather events of the past year. From 2012 to 2015, the number of research groups submitting studies to this issue has grown by more than a factor of five. A goal of this report is to provide a snapshot of the current state of the science of attribution of extreme weather events and to provide recommendations for what might be useful future avenues of both research and applications within this field.

Like all areas of study, terminology matters. As this field is relatively new, not everyone may be familiar with terms such as “counterfactual,” “fraction of attributable risk,” or “selection bias.” Because the committee chose to use the terminology as it is defined and used in the relevant literature we have included a Glossary that defines these key terms.

A reoccurring theme of this report is the importance of the framing of any attribution question. Although climate scientists are frequently asked “Was a given observed weather event caused by climate change?” we believe this is a poorly formed (or ill-posed) question that rarely has a scientifically satisfactory answer. The report discusses appropriate ways to frame attribution questions as well as the interplay between meteorological and human-made factors in the realization of extreme events.

In addition to exploring framing and attribution methods, the report provides a synopsis of the attribution of nine specific types of extreme events. Not every type of event discussed is a pure meteorological event. Droughts, floods, and wildfires, for instance, all have human, as well as natural, components. Land management, controlled burning, and dams and levees impact the magnitude and frequency of these extreme events. The committee believes there is a large weather and climate signal to these types of events, however, and climate scientists are frequently asked to comment on them.

I want to thank our numerous sponsors: the David and Lucile Packard Foundation, the Heising-Simons Foundation, the Litterman Family Foundation, the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Administration (NOAA), and the U.S. Department of Energy, with additional support from the Arthur L. Day Fund of the National Academy of Sciences. In addition to meeting the needs of our sponsors, the committee hopes this report will be of use to the scientific community, the media, and policy makers who are interested in this topic.

Over the course of just 3 months the committee held a number of webinar meetings, met twice in person, and conducted a widely attended community workshop where we heard a diversity of views from the international community working on event attribution. During these meetings the committee gathered information, discussed and debated their views, and crafted this report. Over the course of the study, the committee engaged with international and U.S. scientists who spearheaded development of extreme event attribution approaches, as well as with the broader detection and attribution and climate science communities. (See Appendixes B and C for the names of the experts the committee consulted.)

In closing, I want to personally thank my fellow committee members for their sustained hard work and exceptional dedication to this report. When we started this process, many people believed that it would take more than 1 year to produce such a report. That Attribution of Extreme Weather Events in the Context of Climate Change was produced within 6 months is a testament to the focus and commitment of each member of this committee. I also want to thank and note with great appreciation the incisive and thoughtful comments of our reviewers, whose efforts significantly improved this report, and to thank everyone who gave of their time and expertise to speak at our workshop, on our webinars, or otherwise communicate with the committee during our study process. Finally, I want to acknowledge the superb efforts of the National Academies of Sciences, Engineering, and Medicine staff, led by Katie Thomas took our many disparate inputs, made them into a collective whole, kept us focused and on schedule, and did so with constant grace, cheerfulness, and good humor. Thank you.

David W. Titley, Chair
Committee on Extreme Weather Events and Climate Change Attribution

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

This page intentionally left blank.

Page xiii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Acknowledgments

This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its 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 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:

ALEXIS HANNART, Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos, Buenos Aires, Argentina

BRIAN J. HOSKINS, Imperial College London, UK

KRISTINA B. KATSAROS, Northwest Research Associates, Inc., Freeland, WA

KELLY KLIMA, Carnegie Mellon University, Pittsburgh, PA

LAI-YUNG RUBY LEUNG, Pacific Northwest National Laboratory, Richland, WA

KATHARINE RICKE, Carnegie Institution for Science, Stanford, CA

SONIA I. SENEVIRATNE, ETH Zurich, Switzerland

SUSAN SOLOMON, Massachusetts Institute of Technology, Cambridge

DÁITHÍ STONE, Lawrence Berkeley National Laboratory, Berkeley, CA

PETER STOTT, UK Met Office, Exeter

MICHAEL J. TODD, Cornell University, Ithaca, NY

THOMAS H. VONDER HAAR, Colorado State University, Fort Collins

Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions nor did they see the final draft of the report before its release. The review of this report was overseen by M. Granger Morgan, Carnegie Mellon University, Pittsburgh, PA; and Andrew Solow, Woods Hole Oceanographic Institution, Woods Hole, MA, 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 committee would like to thank the following individuals who shared their expertise with the committee through presentations and discussions: Myles Allen, University

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

of Oxford; Elizabeth Barnes, Colorado State University; Heidi Cullen, Climate Central; Timothy DelSole, George Mason University; Noah Diffenbaugh, Stanford University; Randall Dole, National Ocean and Atmospheric Administration (NOAA) Earth Systems Research Laboratory; Kerry Emanuel, Massachusetts Institute of Technology; Chris E. Forest, Pennsylvania State University; Stephanie Herring, NOAA National Centers for Environmental Information; Martin Hoerling, NOAA Earth Systems Research Laboratory; David Karoly, University of Melbourne/University of Oklahoma; Eric Kasischke, National Aeronautics and Space Administration; Thomas Knutson, NOAA Geophysical Fluid Dynamics Laboratory; Kenneth Kunkel, NOAA Cooperative Institute for Climate and Satellites; Jay Lawrimore, NOAA National Centers for Environmental Information; Geert Jan van Oldenborgh, The Royal Netherlands Meteorological Institute (KNMI); Naomi Oreskes, Harvard University; Friederike Otto, University of Oxford; Tim Palmer, University of Oxford; Judith Perlwitz, NOAA Earth Systems Research Laboratory; Thomas Peterson, NOAA National Climactic Data Center; Fernando Prates, European Centre for Medium-Range Weather Forecasts; David Rupp, Oregon State University; Leonard Smith, University of Oxford; William Sweet, NOAA National Ocean Service; Michael Tippett, Columbia University; Jeffrey Trapp, University of Illinois; Kevin Trenberth, National Center for Atmospheric Research; Steven Vavrus, University of Wisconsin; Mike Wallace, University of Washington; Michael Wehner, Lawrence Berkeley National Laboratory; Antje Weisheimer, European Centre for Medium-Range Weather Forecasts; and Pascal Yiou, Climate and Environmental Sciences Laboratory (LSCE), France.

Page xvii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Glossary1

Attribution: The process of evaluating the relative contributions of multiple causal factors to a change or an event with an assignment of statistical confidence (Hegerl et al., 2010).

Bias: A term used by statisticians to mean the difference between the true quantity and the estimates of that quantity based on data from repeated studies with statistically equivalent samples of data.

Causal factors: Influences on the climate system, including both external forcings—which may be either anthropogenic (greenhouse gases [GHGs], aerosols, ozone precursors, land/water use) or natural (volcanic eruptions, solar cycle modulations)—and slowly varying components of the system (sea-surface temperatures [SSTs], sea ice, soil moisture, snow cover) that are known to influence climatic conditions on seasonal timescales.

Causality: The relationship between something that happens or exists and an effect, result, or condition for which it is responsible.

Conditioning: The process of limiting an attribution analysis to particular types of weather or climate situations. For example, an attribution study may assess whether human influence on the climate plays a role in a given type of event when El Niño “conditions” prevail.

Counterfactual: From the perspective of attribution studies, counterfactual or counterfactual world refers to a hypothetical “control” world that has only been impacted by natural forcings and internal variability. In practice it usually refers to the observed climatic conditions (e.g., a specific sea-surface temperature [SST] distribution) as they might have occurred had anthropogenic forcing been absent.

Detection: Detection of change is defined as the process of demonstrating that climate or a system affected by climate has changed in some defined statistical sense without providing a reason for that change (Hegerl et al., 2010).

Dynamic: Concerning the motion of bodies under the action of forces. In the context of event attribution, dynamics would include both large-scale circulation patterns—which can modulate temperature and precipitation extremes—and storms.

___________________

1 The Intergovernmental Panel on Climate Change reports and the National Climate Assessment are excellent resources for climate-related definitions.

Page xviii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Ensemble: A collection of similar entities. In climate science, the term usually refers to a collection of simulations by a single model but with different initial conditions (hence different internal variations) or to a set of simulations of similar design by different climate models.

Exceedance probability: Probability that a quantity (e.g., temperature or precipitation) will exceed some specified threshold.

Extreme event: A weather or climate event that is rare at a particular place (and, sometimes, time of year) including, for example, heat waves, cold waves, heavy rains, periods of drought and flooding, and severe storms. Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than a particular percentile (e.g., 1st, 5th, 10th, 90th, 95th, 99th) of a probability density function estimated from observations expressed as departures from daily or monthly means.

Factual: From the perspective of attribution studies, factual refers to the currently observed world as it exists in the context of climate change.

(External) Forcing: A term that refers to a forcing agent outside the climate system causing a change in the climate system. Examples include volcanic eruptions, solar variations and anthropogenic changes in the composition of the atmosphere, and land use change.

Fraction of attributable risk (FAR): The fraction of the likelihood of an event that is attributable to a specific causal factor.

Framing: The process of posing scientific questions that arise when an event occurs and establishing the context within which they are answered (e.g., whether some kind of conditioning is involved). Framing may include translation of a question such as “Did human-induced climate change cause this event?” into one or more questions that science may be better able to answer: for instance, “Has human influence on the climate increased the frequency or intensity of events like the one that has just occurred?”

Internal variability: The technical term that is often used to describe the natural, unforced, chaotic variability that occurs continually in the climate system. It is a component of natural variability.

Model: A set of ideas; a physical representation or set of formulas that describe a process or system. In climate science, and in this report, the term usually refers to a set of equations describing the physical laws governing the behavior of the atmosphere, ocean, sea ice, land surface, and other components of the Earth system, whose solutions simulate the time evolution of the system.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

Natural variability: Internally (such as El Niño–Southern Oscillation) and externally (e.g., volcanic eruptions or changes in solar radiance) induced natural climate variability that occurs without anthropogenic forcing.

P0: Counterfactual probability p0 (i.e., the probability of an event in a world without human influence on climate).

P1: Factual probability p1 (i.e., the probability of an event in the currently observed world as it exists in the context of climate change).

Return time: A return time (or period) is a commonly used metric of probability; for example, a 100-year return time means that in any given year, there is a 1-in-100 chance of the threshold being reached. If the climate were not changing, return time could also be interpreted as the average time between events, but it should not be interpreted as the time that will pass before an event occurs again.

Risk ratio: The ratio of probabilities under two different conditions or settings; in event attribution this is generally the ratio of the probability under anthropogenic forcing (the factual scenario) to that under the counterfactual scenario. While well established in epidemiology, the term is a misnomer because it is a ratio of probabilities and does not involve risk as formally defined to account for both probability and magnitude of impact.

Selection bias: A term used by statisticians to describe the systematic errors in probabilistic inference that can arise when the data that are collected or analyzed are not representative of the population of interest. A famous example is the mis-prediction of the outcome of the 1948 U.S. presidential election (Dewey versus Truman) based on a telephone survey, because in those days only the wealthier members of society had their own telephones.

Thermodynamic: Concerning heat and temperature and their relation to energy and work. In the context of event attribution, thermodynamics would include behavior related to the warming and increased moisture-holding capacity of the atmosphere.

Variance: A term used by statisticians to mean the variability of an estimate of a quantity based on one sample of data around the average estimate of that quantity that would be calculated based on data from repeated studies with statistically equivalent samples of data.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×

This page intentionally left blank.

Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R1
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R2
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R3
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R4
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R5
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R6
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R7
Page viii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R8
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R9
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R10
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R11
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R12
Page xiii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R13
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R14
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R15
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R16
Page xvii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R17
Page xviii Cite
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R18
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R19
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/21852.
×
Page R20
Next: Summary »
Attribution of Extreme Weather Events in the Context of Climate Change Get This Book
×
Buy Paperback | $79.00 Buy Ebook | $64.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts.

Even with evidence of these broad trends, scientists cautioned in the past that individual weather events couldn't be attributed to climate change. Now, with advances in understanding the climate science behind extreme events and the science of extreme event attribution, such blanket statements may not be accurate. The relatively young science of extreme event attribution seeks to tease out the influence of human-cause climate change from other factors, such as natural sources of variability like El Niño, as contributors to individual extreme events.

Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!