Atlas of Global and Regional Climate Projections (Annex I)

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An Atlas of Global and Regional Climate Projections will be provided as Annex I of the WGI AR5. The Atlas will in-clude maps for a limited number of key physical variables, simulated for a range of scenarios, for various time horizons within the 21st Century. The maps are intended to enhance the accessibility of information to users and stakeholders, and assist the hand-over of this information between IPCC Working Groups.

Figure: Decadally averaged changes in annual mean precipitation (% change in pre-cipitation per degree of warming relative to a 1900-1950 base period), based upon a suite of AOGCMs for the SRES A1B scenario. (From Solomon et al. 2009)

The Atlas will be produced by an Editorial Team consisting of two authors each from Chapters 11, 12, and 14. This Editorial Team will be assisted by an Advisory Board, consisting of two WGI Vice-Chairs and an invited WGII AR4 lead author.

2010 2011 2012 2013

Review Review

20142009

0th-Order Draft 1st-Order Draft Review 2nd-Order Draft Review Final Draft Review Outreach & SynthesisPreparationAuthor SelectionScoping

AR5 ScopingMeeting

AR5 OutlineApproved 1

Lead AuthorMeeting 2

Lead AuthorMeeting 3

Lead AuthorMeeting 4

Lead AuthorMeeting

IPCC WGI AR5 Approval Plenary

AR5 SynthesisApproval PlenarySubmitted Paper

Cut-offAccepted Paper Cut-off

The WGI Bureau has selected 258 Lead Authors and Review Editors, representing 44 countries, to write the WGI AR5. This selection came from within a larger pool of government and WGI Bureau nominated experts. Over 65% of the scientists are new to the IPCC WGI assessment process. Each chapter is led by two Coordi-nating Lead Authors (with three in Chapter 2). For full details: www.ipcc-wg1.unibe.ch/AR5

The WGI AR5 will undergo one informal, and two formal rounds of external review. The role of the carefully se-lected Review Editors (between two and four per chapter) will be crucial in ensuring that authors respond ap-propriately to all formally submitted review comments, and that emerging issues and genuine scientific contro-versies are reflected adequately in the assessment.

WRITING THE WGI AR5

Poster design and creation: Simon Allen, 2010

WORKING GROUP I BUREAU AND TECHNICAL SUPPORT UNITCo-Chairs: Thomas Stocker, Qin Dahe

Vice-Chairs: Jean Jouzel, Abdalah Mokssit, Fatemeh Rahimzadeh, Fredolin Tangang, David Wratt, Francis Zwiers

Technical Support Unit (TSU): Pauline Midgley, Gian-Kasper Plattner, Melinda Tignor, Simon Allen, Vincent Bex, Judith Boschung, Alex Nauels

CONTACT - IPCC WGI TSU, University of Bern, Switzerland. wg1@ipcc.unibe.ch www.ipcc-wg1.unibe.ch

Figure a: Asian Monsoon patterns result from the complex in-terplay between many factors, including sea surface tempera-tures (SSTs), variations in solar output, snow cover and soil moisture over continental Asia, and the position and strength of prevailing westerly winds. (From Wahl and Morrill 2010)

Regional Climate Change (Chapters 11, 12, and 14)

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Figure b: Projected mean changes of heatwave day frequency in Europe, for six simulations of the re-gional modelling project ENSEMBLES, forced with the SRES A1B scenario. Changes are expressed as the ratio between scenario and control periods. (From Fischer & Schär 2010)

Regional integration is a key element of the WGI AR5. Chapter 14 will assess the most important climate phe-nomena relevant for regional climate change, including worldwide monsoon systems such as the Asian Mon-soon, El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), and others. The regional expression of climate variability and extreme events will be projected in the near-term (Chapter 11), long-term (Chapter 12), and considered within the integrated regional assessment (Chapter 14). The detection and attribution of regional climate change to natural and anthropogenic forcings will be assessed in Chapter 10 of WGI AR5.

WGI AR5 will include separate near- and long-term projection chapters, based on models from the CMIP and other community projects, evaluated in Chapter 9. This new structure en-compasses assessment of near-term climate predictability, including seasonal to interan-nual projection, and issues of climate change commitment, irreversibility, and potentially abrupt changes relevant to longer term projec-tions. Concepts of projection uncertainty will be introduced in Chapter 1 of WGI AR5.

Near- and Long-term Climate Change (Chapters 11 and 12)

Figure: Relative sources of uncertainty in global decadal mean surface temperature projections expressed as the prediction uncertainty divided by the expected change, relative to the 1971-2000 mean. For near-term, model uncertainty is large, with internal variability important for the first decade or two. For long-term, scenario uncer-tainty becomes most important. (Modified from Hawkins and Sutton 2009)

Near-term climate

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Figure: Selected interactions between carbon and ni-trogen cycles. Red arrows denote direct anthropogenic impacts on these interactions, and blue arrows denote natural interactions which may be anthropogenically modified. (+), (–), (?) signs indicate that the interaction causes an increase, decrease, or unknown impact on the relevant factor shown. Arrow thicknesses denote the relative magnitude of these interactions.(From Gruber and Galloway 2008)

The carbon cycle will be assessed within a dedi-cated end-to-end chapter in WGI AR5. Attention will be given to interactions between carbon and other biochemical cycles, including the nitrogen cycle, and feedbacks with the climate system which are relevant for near- and long-term climate projections (Chapters 11 and 12). Paleo information (Chapter 5) will provide evidence for past changes in Carbon and other Biogeochemical cycles, and related cli-mate feedbacks.

Carbon, Other Biochemical Cycles, and Climate (Chapter 6)

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Among the major long-term consequences of climate change is global sea level change. The AR5 will provide an end-to-end assessment of sea level changes, observations, related causes, future projections, and regional expression, within a new, dedicated chapter. Chapter 13 will draw upon oceanic and cryospheric observations provided in Chapters 3 and 4.

Figure b: Rate of surface elevation changes in Ant-arctica and Greenland, measured 2003-2007, using repeat laser satellite altimetry from ICESat. (From Pritchard et al. 2010)

Figure a: Global mean sea level change (1850-2100). Observations include tide gauge data (red) and satellite altimetry (black); derived 19th Century long-term mean is given in blue. Projections are shown for (i) the multi-model ensemble used in IPCC AR4 (including an additional 20 cm range from potential ice sheet instability), and (ii) a selec-tion of recent semi-empirical models. Projections are given as a 5-95% confidence range, or with an uncertainty equal to 1 SD of the statistical fit. Upper and lower limits of sea level rise calculated based on physical constraints to the land ice contributions are also indicated (Pfeffer et al. 2008). (Modified from Nicholls and Cazenave 2010)

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Sea Level Change and its Components (Chapters 3, 4, and 13)

Chapter 13 will specifically address the role of ice sheets and ice sheet stability relating to past and future sea level change. The latest mass balance observations for ice sheets, glaciers and ice caps will be assessed in Chapter 4.

Meteorology

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Clouds, Aerosols, and Radiative Forcing (Chapters 7 and 8)

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Figure a: Changes in the concentration of cloud-active aerosol alter the precipitation efficiency of clouds, thereby changing cloud amount, and hence, the radiative forcing of the climate system. Aerosol-cloud-precipitation interactions (green) are specifi-cally addressed in Chapter 7 of WGI AR5. (From Stevens & Feingold 2009)

Figure b: Calculated 100-year Global Warming Po-tentials (GWPs) for methane, carbon monoxide, and nitrogen oxides, including direct and indirect cli-mate forcing with aerosols compared with calcu-lated GWPs without considering aerosols. (Modified from Shindell et al. 2009)

For the first time in IPCC, the science of clouds and aerosols, interactions between clouds, water vapour, aero-sols and precipitation, and their role in observed and projected climate change will be assessed in a dedicated chapter. This chapter will inform and link with the assessment of anthropogenic and natural radiative forcing given in Chapter 8. Observed changes in clouds and atmospheric composition will be assessed in Chapter 2.

1. IntroductionObservations and Paleoclimate Informations

2. Observations: Atmosphere and Surface3. Observations: Ocean4. Observations: Cryosphere5. Information from Paleoclimate Archives

Process Understanding6. Carbon and Other Biogeochemical Cycles7. Clouds and Aerosols

From Forcing to Attribution of Climate Change8. Anthropogenic and Natural Radiative Forcing 9. Evaluation of Climate Models

10. Detection and Attribution of Climate Change: from Global to RegionalFuture Climate Change and Predictability

11. Near-term Climate Change: Projections and Predictability 12. Long-term Climate Change: Projections, Commitments and Irreversibility

Integration

13. Sea Level Change14. Climate Phenomena and their Relevance for Future Regional Climate Change

Annex I: Atlas of Global and Regional Climate Projections

WGI AR5 OUTLINEIn October 2009, at its 31st Plenary Session, the Intergovernmental Panel on Climate Change (IPCC) approved the outline for the Working Group I (WGI) contribution to the IPCC Fifth Assessment Report (AR5). The outline of the WGI AR5 has been developed through a scoping process involving climate change experts from all relevant disciplines and users of IPCC reports. The approved outline includes several new elements highlighted here. These reflect recent advances in scientific understanding of climate change. A detailed outline including bullets specifying the chapter contents is available at www.ipcc-wg1.unibe.ch/outline

INTRODUCTION

Working Group I Contribution to the IPCC Fifth Assessment Report

Climate Change 2013: The Physical Science Basis