© Yann Arthus-Bertrand / Altitude

Highlights of the New IPCC Report Gian-Kasper Plattner

Director of Science, IPCC WGI TSU

259 Authors from 39 Countries WGI Co-Chairs & TSU Team

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Observation

Understanding

Future

Warming in the climate system is unequivocal

Human influence on the climate system is clear

Limiting climate change will require substantial and sustained reductions of

greenhouse gas emissions

Observation What has changed?

Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.

In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years (medium confidence).

Fig. SPM.1a

Ano

mal

y (°

C) r

elat

ive

to 1

961-

1990

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Fig. SPM.3

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Warming of the climate system is unequivocal, [...]

Understanding Why has it changed?

Global mean warming since 1951 (°C)

Solar, Volcanic

Aerosols

CO2, CH4, N2O

Anthropogenic

Internal Variability

Observed

Fig. TS.10

The observed warming 1951−2010 is approximately 0.6°C to 0.7°C.

© IP

CC

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Global mean warming since 1951 (°C)

Solar, Volcanic

Aerosols

CO2, CH4, N2O

Anthropogenic

Internal Variability

Observed

Fig. TS.10

© IP

CC

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It is extremely likely that human influence has been the dominant cause of the observed

warming since the mid-20th century.

Global mean warming since 1951 (°C)

Solar, Volcanic

Aerosols

CO2, CH4, N2O

Anthropogenic

Internal Variability

Observed

Fig. TS.10

It is extremely likely that human influence has been the dominant cause of the observed

warming since the mid-20th century.

© IP

CC

201

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Global mean warming since 1951 (°C)

Solar, Volcanic

Aerosols

CO2, CH4, N2O

Anthropogenic

Internal Variability

Observed

Fig. TS.10

Human influence on the climate system is clear.

© IP

CC

201

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Future How will it change?

Fig. SPM.7a

Global surface temperature change for the end of the 21st century is likely to exceed 1.5°C relative to

1850−1900 for all scenarios except RCP2.6.

Global mean surface temperature change from 1986-2005

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Global mean sea level will continue to rise during the 21st century and virtually certain beyond 2100

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Fig. SPM.9

RCP2.6 (2081-2100), likely range: 26 to 55 cm RCP8.5 (2081-2100), likely range: 45 to 82 cm

Fig. SPM.9

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Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond.

Fig. SPM.10

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Fig. SPM.10

Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

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The four Elements of the Fifth WGI Assessment Report

14 Chapters

Atlas: Regional Projections

1,140,000 Words, ca. 2000 Pages 1250 Figures und Diagrams

Timeseries und Maps for 35 Regions of the World, 2 Mio G Bytes

Summary for Policymakers

Technical Summary 55'000 Words, ca. 90 Pages

14'000 Words, 22 Pages, 10 Figures

Principles Governing IPCC Work (1998, 2003, 2006)

The Elements of the Technical Summary

v Summary of the 14 Chapters Observations – Drivers – Understanding – Projections – Key Uncertainties

v Technical Boxes e.g., RCP Scenarios, Last 15 years, Climate- (Geo-) engineering

v Thematic Focus Elements e.g., Water Cycle Change, Irreversibility and Abrupt Change, Climate Sensitivity, Climate Targets, Climate Extremes

© Yann Arthus-Bertrand / Altitude

www.climatechange2013.org Further Information