Table Of ContentUnderstanding the
Earth System
Global Change Science for Application
Earth system science has been described as ‘a science struggling with
problems too large for its participants, but too important to ignore’. This
exciting new book provides an overview of this enormous, rapidly growing
field, tackling current scientific debates and policy-relevant questions on the
global environment.
The multi-disciplinary author team explains the what, the how and the
why of climate science, providing a review of research from the last decade,
illustrated with cutting-edge data and observations. A key focus is the
development of analysis tools that can be used to demonstrate society’s options
for mitigating and adapting to increasing climate risks. Emphasis is given to
the importance of Earth system feedback mechanisms and the role of the
biosphere. The book explains advances in modelling, process understanding,
and observations, and the development of consistent and coherent studies of
past, present and ‘possible’ climates.
This highly illustrated, data-rich book is written both for those who use
Earth system model outputs and need to know more about the science behind
them, and those who develop Earth system models and need to know more
about the broader context of their research. The author team is made up of
leading scientists involved in QUEST, a major recently completed, UK-led
research programme. The book forms a concise and up-to-date reference for
academic researchers or students in the fields of climatology, Earth system
science and ecology. By highlighting the application of scientific results to
contemporary policy issues, the book is also a vital resource for professionals
and policy-makers working on any aspect of global change.
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Understanding the
Earth System
Global Change Science for Application
Edited by
Sarah Cornell
Stockholm Resilience Centre
I. Colin Prentice
Macquarie University
Joanna House
University of Bristol
Catherine Downy
European Space Agency Climate Office, Harwell
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cambridge university press
Cambridge, New York, Melbourne, Madrid, Cape Town,
Singapore, São Paulo, Delhi, Mexico City
Cambridge University Press
The Edinburgh Building, Cambridge CB2 8RU, UK
Published in the United States of America by Cambridge University Press, New York
www.cambridge.org
Information on this title: www.cambridge.org/9781107009363
© Cambridge University Press 2012
This publication is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without the written
permission of Cambridge University Press.
First published 2012
Printed in the United Kingdom at the University Press, Cambridge
A catalogue record for this publication is available from the British Library
Library of Congress Cataloguing in Publication data
ISBN 978-1-107-00936-3 Hardback
Additional resources for this publication at www.cambridge.org/QUEST
Cambridge University Press has no responsibility for the persistence or
accuracy of URLs for external or third-party internet websites referred to in
this publication, and does not guarantee that any content on such websites is,
or will remain, accurate or appropriate.
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Contents
List of editors page vii
List of scientific editorial team members viii
List of contributing authors x
Foreword xiii
Preface xv
Acknowledgements xxiii
List of units xxv
1 Earth system science and society: a focus on 3.3 Methods for observing and understanding the
the anthroposphere 1 past 74
Sarah E. Cornell, Catherine J. Downy, Evan D. G. 3.4 How climate has altered in the past 78
Fraser and Emily Boyd 3.5 Response of climate change to forcing 79
3.6 Case studies of climate perturbations and
1.1 The Earth system and the ‘problematic
responses 85
human’ 1
3.7 Natural perturbations as a guide to the future
1.2 Conceptualizing the ‘human dimension’ from
behaviour of the Earth system 94
an Earth system perspective 6
1.3 Social science perspectives on the Earth 4 The Earth system feedbacks that matter
system 16 for contemporary climate 102
1.4 Creating usable and useful integrated research Pierre Friedlingstein, Angela V.
about the Earth system 30 Gallego-Sala, Eleanor M. Blyth, Fiona E. Hewer,
Sonia I. Seneviratne, Allan Spessa, Parvadha
2 Fundamentals of climate change science 39
Suntharalingam and Marko Scholze
I. Colin Prentice, Peter G. Baines, Marko Scholze
and Martin J. Wooster 4.1 Introduction 102
4.2 Land–atmosphere biogeophysical
2.1 Observing and studying climate 39
feedbacks 105
2.2 Fundamentals of climatology 42
4.3 Carbon-cycle feedbacks 108
2.3 Fundamentals of terrestrial ecosystem
4.4 Nitrous oxide feedbacks 110
science 53
4.5 Methane feedbacks 111
2.4 The global carbon cycle 60
4.6 Fire feedbacks 115
2.5 Prognosis 64
4.7 Human feedbacks 119
3 How has climate responded to natural
5 Earth system models: a tool to understand
perturbations? 72
changes in the Earth system 129
Eric W. Wolff, Sandy P. Harrison, Reto Knutti,
Marko Scholze, J. Icarus Allen, William J. Collins,
Maria Fernanda Sanchez-Goñi, Oliver Wild,
Sarah E. Cornell, Chris Huntingford, Manoj
Anne-Laure Daniau, Valérie Masson-Delmotte,
M. Joshi, Jason A. Lowe, Robin S. Smith and
I. Colin Prentice and Renato Spahni
Oliver Wild
3.1 Introduction 72
5.1 Introduction 129
3.2 Climate perturbations 72
5.2 Horses for courses: no model is ‘best’ 132
v
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Contents
5.3 Understanding observations 139 7.1 Introduction: from human perturbation to
5.4 Predicting future global change 145 biosphere management 202
5.5 A perspective on future model 7.2 How big a mitigation effort is required? 204
developments 151 7.3 How has the biosphere influenced climate
5.6 The outlook for Earth system science 153 change in the recent past? 209
7.4 Mitigation potential in the forest sector 214
6 Climate change impacts and adaptation: an
7.5 Mitigation potential in the agricultural
Earth system view 160
sector 217
Richard A. Betts, Nigel W. Arnell, Penelope M.
Boorman, Sarah E. Cornell, Joanna I. House, Neil 7.6 Mitigation in the bioenergy sector 219
R. Kaye, Mark P. McCarthy, Douglas J. McNeall, 7.7 Critical issues in land-based mitigation 225
Michael G. Sanderson and Andrew J. Wiltshire 7.8 Opportunities and priorities for action 236
6.1 Introduction 160 8 Society’s responses and knowledge
6.2 Measuring and modelling potential impacts of gaps 245
climate change 163 Sarah E. Cornell and I. Colin Prentice
6.3 Evidence for impacts of climate change in the
8.1 Introduction 245
recent past 180
8.2 Some unresolved issues 245
6.4 Global-scale impacts of future climate
8.3 Envisioning the future 250
change 184
8.4 Concluding remarks 254
6.5 Adaptation in practice 192
6.6 Key messages 194
7 The role of the land biosphere in climate-
change mitigation 202 List of acronyms 257
Joanna I. House, Jessica Bellarby, Hannes Glossary 261
Böttcher, Matthew Brander, Nicole Kalas, Pete Index 263
Smith, Richard Tipper and Jeremy Woods
vi
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Editors
Sarah Cornell (executive editor) works on integra- International Geosphere–Biosphere Programme’s
tive socio-environmental research at the Stockholm (IGBP’s) Analysis, Integration and Modelling of the
Resilience Centre. In her previous role at the University Earth System (AIMES) project until 2010, and now
of Bristol, she was responsible for the science man- directs the Australian Terrestrial Ecosystem Research
agement and the synthesis phase of QUEST, the UK Network’s modelling facility, and jointly co-ordinates
Natural Environment Research Council’s research pro- the biodiversity theme for Macquarie’s Climate Futures
gramme for Earth system science. Her research back- Centre.
ground is in marine and atmospheric chemistry, and
her interdisciplinary interests are in the anthropogenic Joanna House (policy editor) has been working in the
changes in global biogeochemistry, socio-economics, field of climate science for over 20 years. As science and
environmental management, and the philosophy and policy officer for QUEST, her role was to coordinate
methodology of integrative research. Dr Cornell was the liaison between researchers and the policy/prac-
a founding member of the UK Human Dimensions tice user communities. Now a Leverhulme Research
Committee on Global Change. She established the Fellow in the Cabot Institute at the University of
University of Bristol’s MSc in Earth System Science, Bristol, her research focuses on the carbon cycle;
the UK’s first post-graduate programme on this topic, land-use change and greenhouse-gas emissions; miti-
and is active in promoting education for sustainability. gation of climate change through avoided deforest-
In recent years, she has become more engaged in use- ation, forestry and bioenergy; emissions scenarios;
oriented transdisciplinary research, with a particular and policy implications. Dr House was a contribut-
focus on conceptualizations of humans in the Earth ing author for the Nobel Prize-winning IPCC Third
system. Assessment Report, and a convening lead author
on the Millennium Ecosystem Assessment, which
Colin Prentice (senior editor and chair of the scien- received the Zayeed Prize for Environmental Science.
tific editorial team) served as the scientific leader and She has also contributed her expertise to reports
chair of the QUEST research programme. He is now such as the Stern Review on the Economics of Climate
a professor at both Macquarie University, Sydney and Change (2006) and the Eliasch Review of Forests and
Imperial College, London, where he and his collabo- Climate Change (2008).
rators are developing a ‘next-generation’ biosphere
model combining Earth system observations with Catherine Downy (technical editor) has a background
developments in plant functional ecology. His over- in science management and liaison, working to bring
all research goal is to understand the interplay of the scientists together under the growing banner of ‘Earth
biosphere and its physical environment, including the system science’. She ran the UK’s first open conference
causes and consequences of natural and human-caused in this field, Earth System Science 2010, in Edinburgh,
changes in climate and the global carbon and nitro- successfully uniting natural scientists from a range of
gen cycles. He was awarded the Milutin Milankovitch disciplines, together with those from the social sciences
medal in 2002, and shared in the award of the Nobel and humanities. She now holds the post of liaison offi-
Peace Prize to the Intergovernmental Panel on Climate cer for the IGBP and European Space Agency (ESA),
Change in 2007. Professor Prentice co-chaired the based at the Climate Office in ESA Harwell.
vii
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Scientific editorial team members
Eric Wolff is the science leader of the Chemistry and Project (C4MIP). He is a member of the science steering
Past Climate programme, at the British Antarctic committee of AIMES and of the Earth System Science
Survey. He also holds an honorary visiting professor- Partnership’s Global Carbon Project. Since 1994, he has
ship at Southampton University’s School of Ocean and participated in the IPCC’s climate assessments, and is
Earth Science. Professor Wolff’s career has centred on currently a lead author in Working Group I of the IPCC
investigations of Quaternary and recent climate using Fifth Assessment Report.
ice cores. His areas of interest bridge the physical and
chemical characteristics of ice, informing understand- Marko Scholze is a Natural Environment Research
ing of palaeoclimate and polar atmospheric chemistry. Council (NERC) Advanced Research Fellow in the
Professor Wolff has served on many polar science field School of Earth Sciences, University of Bristol, and
seasons, both in Antarctica and Greenland. He was the a visiting fellow at the University of Hamburg. His
science chair of the European Project for Ice Coring in research focuses on the dynamics of terrestrial ecosys-
Antarctica (EPICA), a major research initiative that has tems and their interactions with the climate system.
produced detailed records of climate and atmospheric The responses of the terrestrial biosphere and carbon
composition spanning the last 800,000 years, provid- fluxes to changes in climate can be seen over various
ing unprecedented insights into the workings of Earth’s timescales. Dr Scholze’s research therefore spans pal-
climate system. He now co-chairs the international aeo glacial–interglacial transitions, interannual vari-
ice-core co-ordinating group IPICS, and its European ability and future global warming. His research goal
counterpart, EuroPICS. He is a member of the steer- is to quantify the anthropogenic perturbation of the
ing committee of the IGBP’s Past Global Changes carbon cycle, including the detection of measures to
(PAGES) project, and a former committee member mitigate climate change. He uses observational data
for the International Global Atmospheric Chemistry and data assimilation techniques to optimize models of
(IGAC) project. He was the 2009 Agassiz medallist of the Earth system. His research also addresses the press-
the European Geosciences Union (EGU) cryosphere ing question of what constitutes ‘dangerous climate
division, and was elected Fellow of the Royal Society change’ and how to assess the risks of climate change on
in 2010. ecosystems. Dr Scholze contributed to the Millennium
Ecosystem Assessment.
Pierre Friedlingstein is Professor of Mathematical
Modelling of Climate Systems at Exeter University. Richard Betts is Head of Climate Impacts at the Met
His research interests are in the field of global carbon Office Hadley Centre. His research specialism is in eco-
cycle and global biogeochemical cycles, with particu- system–hydrology–climate interactions, extending to
lar interest in the interactions between climate and bio- climate impacts on urbanization, health, industry and
geochemistry over timescales ranging from the glacial finance. He is particularly interested in climate-change
cycles to future IPCC-like projections. His research impacts on water resources and the role of vegetation in
contributed to the identification of the positive feedback modifying this impact, and in climate-change impacts
between climate change and carbon cycle, a process that on large-scale ecosystems and interactions with defor-
profoundly alters our perspectives on future climate estation (with a particular interest in Amazonia). He
change. This work drives his interest in the evaluation leads the Met Office’s climate consultancy area, which
of land surface models and Earth system models over works directly with end-users in a wide range of sectors,
the last millennium. He coordinates the IGBP/WCRP’s to ensure climate-change information is used effectively
viii Coupled Climate Carbon Cycle Intercomparison for decision-making. Dr Betts leads the impacts theme
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Scientific editorial team
of the Joint UK Land Environment Simulator (JULES) lead author for the IPCC Fifth Assessment Report. He
community land surface modelling programme. He was also a lead author in the Millennium Ecosystem
was a lead author for Working Group I and a con- Assessment, and a reviewer for the UK Government-
tributing author for Working Group II of the IPCC’s commissioned Stern Review on Economics of Climate
Fourth Assessment Report, and is a Working Group II Change.
ix
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Contributing authors
Icarus Allen is Head of Science (Today’s Models, International Institute for Applied Systems Analysis.
Tomorrow’s Futures) at the Plymouth Marine He is a forest scientist with particular interest in sys-
Laboratory. He specialises in the numerical modelling tems analysis and integrated modelling, specializing
and operational forecasting of marine systems from on the impact of forestry on the carbon cycle.
individual cells to shelf-wide ecosystems.
Emily Boyd is a reader in environmental change and
Nigel Arnell is the director of the Walker Institute for human communities at the University of Reading,
Climate Change Research and Professor of Climate also affiliated to the Stockholm Resilience Centre. Her
System Science at Reading University. His research research focus is on the governance and politics of
focuses on the impacts of climate change on river flows, natural resource management in the context of global
water resources and their management. environmental change.
Peter Baines is a professorial fellow in the Department Matthew Brander is a senior analyst at Ecometrica,
of Infrastructure Engineering at the University of providing expert advice on greenhouse-gas account-
Melbourne. He is a meteorologist and oceanographer ing and ecosystem services, with particular interests in
interested in climate dynamics on decadal timescales bioenergy generation.
and on the effects of topography on atmospheric flows.
Bill Collins leads research into the interactions
Jessica Bellarby is a research fellow at the University between atmospheric composition and climate at the
of Aberdeen. Her background is in bioremediation UK Met Office, where he led the development of the
and environmental microbiology. She now works on Hadley Centre Earth system model HadGEM2.
improving process understanding of soil carbon and
Sarah Cornell coordinates the Planetary Boundaries
organic matter.
research initiative at the Stockholm Resilience Centre.
Richard Betts leads the Climate Impacts strategic Her research background is in global biogeochemistry
area of the Met Office Hadley Centre. His interests and in interdisciplinary approaches to environmental
are in large-scale modelling of ecosystem-hydrology- management.
climate interactions and integrated impacts model-
Anne-Laure Daniau is a palaeoclimatologist, explor-
ling, with particular interest in land use change and
ing the palaeorecord to understand the nature of the
deforestation.
relationships between fire, climate, land and ocean
Eleanor Blyth leads the Land Surface Processes mod- changes, and human perturbation. Formerly at the
elling group at the NERC Centre for Ecology and School of Geographical Sciences, University of Bristol,
Hydrology. Her research involves representing the land she now works at University of Bordeaux.
surface in meteorological and hydrological models.
Cat Downy works at the European Space Agency’s
Penelope Boorman is a scientist in the Climate Impacts Climate Office in Harwell. She has a background in
strategic area of the UK Met Office Hadley Centre. Her science management and liaison, working to bring
work focuses on improving the understanding and scientists together under the growing banner of Earth
assessment of dangerous regional impacts of global cli- system science.
mate change.
Evan Fraser holds the Canada Research Chair in
Hannes Böttcher is a research scholar with the Global Human Security and is an associate professor
x Ecosystem Services and Management Program at the in geography at the University of Guelph. He is also an
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