1

Lecture, Summer term 2012, LMU München

An Introduction to Global Atmospheric Modelling

Lecture 7: International climate modelling activities

Veronika EyringDLR - Institut für Physik der Atmosphäre

Oberpfaffenhofen

Content:

• WCRP Overview

• Summary of IPCC AR4 climate assessment

• Preparation for IPCC AR5 climate assessment:

• Coupled Model Intercomparison Project (CMIP)

• Representative Concentration Pathways (RCPs)

• Geoengineering Model Intercomparison Project (GeoMip)

Origin

Stockholm Study Conference (1974)

First World Climate Conference (1979)

Sponsors

World Meteorological Organisation (WMO,1980+)

International Council of Scientific Unions (ICSU,1980+)

Intergovernmental Oceanographic Commission (IOC/UNESCO,1992+)

Objectives

To determine the predictability of climate

To determine the effect of human activities on climate

WCRP OverviewWorld Climate Research Programme

WCRP Domains GEWEXCliC

CLIVARSPARC

CliC

SPARC

GEWEX

CLIVAR

WCRP Projects:Global Energy and Water Cycle Experiment (GEWEX)Climate Variability and Predictability (CLIVAR)Climate and Cryosphere (CliC)Stratospheric Processes And their Role in Climate (SPARC)Surface Ocean-Lower Atmosphere Study (SOLAS)

WCRP Working Groups, Examples

• Working Group on Numerical Experimentation (WGNE)

• Working Group on Surface Fluxes (WGSF)

• Working Group on Coupled Modelling (WGCM) leads the development of coupled ocean/atmosphere/land models used for climate studies on longer time-scales.

WGCM is also WCRP's link to the Earth system modelling in IGBP's Analysis, Integration and Modeling of the Earth System (AIMES) and to the Intergovernmental Panel on Climate Change (IPCC). http://www.clivar.org/organization/wgcm/wgcm.php

Lecture 7: Climate modelling activities, page 5Internationale wissenschaftliche SachstandsberichteMulti-Modell Vorhersagen von Klima-Chemie-Modellen bzw. Klimamodellensind eine wichtige Komponente der in regelmäßigen Abständen erstellten.

WMO/UNEP Ozonberichte bzw. IPCC Klimaberichte

• IPCC AR1 (1990)

• IPCC AR2 (1997)

• IPCC AR3 (2001)

• IPCC AR4 (2007) CMIP3

• IPCC AR5 (2013) CMIP5

• WMO/UNEP (1985)• WMO/UNEP (1989)• WMO/UNEP (1991)• WMO/UNEP (1994)• WMO/UNEP (1998)• WMO/UNEP (2002)• WMO/UNEP (2006) CCMVal-1• WMO/UNEP (2010) CCMVal-2

2007: Friedensnobelpreis für UN Klimarat (IPCC) und Al Gore

1995: Nobelpreis für Chemie an Crutzen, Molina und Rowland

• Verständnis chemischer Prozesse der Bildung und des Abbaus von Ozon

• warnende Vorhersage vor den Folgen einer ungehemmten Emission ozonzerstörender Gase.

}}

Evry, 19 Juin 2007

Greenhouse Gases and Radiative Forcing of the Last 10,000 years

IPCC, AR4, 2007

2

Evry, 19 Juin 2007

Earth energy balance

Evry, 19 Juin 2007

Outgoing solarradiation : 107 W/m2

Incoming solarradiation: 342 W/m2

Outgoing infrared radiation : 235 W/m2

168Surface

UV absorption

30

107 235

77 77

Absorbed by the atmosphere67

78evapo-

transpiration

24

Sensible heat390

Surface IR radiation

350 40 324rayonnement renvoyé vers

la surface

324

24

30

342

165 40

GHG +Aerosols

+1.6 W/m2

SurfaceIR absorption

Additional greenhouse effect

Evry, 19 Juin 2007

Radiative forcing since 1750

IPCC, AR4, 2007

posi

tive

ne

gat

ive

Evry, 19 Juin 2007

Global warming is unequivocalIncrease in:

• Global surface temperatures• Tropospheric temperatures• Global SSTs, ocean Ts• Global sea level• Water vapor

• Rainfall intensity• Precipitation extratropics• Hurricane intensity• Drought• Extreme high temperatures• Heat waves

Decrease in:

• NH Snow extent• Arctic sea ice• Glaciers length• Cold temperatures

IPCC, AR4, 2007

Evry, 19 Juin 2007

100 0.0740.018

50 0.1280.026

Period Rate

Years /decade

Global mean temperatureRank Year

1 1998

2 2005

3 2003

4 2002

5 2004

6 2006

7 2001

8 1997

9 1995

10 1999

11 1990

12 2000

IPCC, AR4, 2007

Evry, 19 Juin 2007

Surface temperature trends

Warming trend over all continents (but Antarctica)Larger trend• over land than ocean• at high latitudes (NH)

3

Evry, 19 Juin 2007Annual anomalies (%) over land from 1900 to 2005; other regions are dominated by variability.

Increases

Decreases

Land precipitation changes

IPCC, AR4, 2007

Evry, 19 Juin 2007

Heat waves

Trend plus variability?Extreme Heat WaveEx. Summer 2003 Europe

IPCC, AR4, 2007

Evry, 19 Juin 2007

Increased Glacier retreat since the early 1990s

Continental glaciers

IPCC, AR4, 2007

Le glacier d’Argentière

(Alpes)

1850

1960

Evry, 19 Juin 2007

Greenland and Antarctic ice sheets

Antarctic ice sheet loses mass mostly through increased glacier flow

Greenland gains mass in the interior, but loses more at the margins

Evry, 19 Juin 2007Melt extent

Greenland ice sheet 2005

Evry, 19 Juin 2007

Sea level Rise

Rate of sea level rise:

1960-2000 : 1.8 mm/yr

1993-2003 : 3.1 mm/yr

Contributions from :• thermal expansion• glaciers• Greenland and Antarctica

Relative to 1961-1990

4

Evry, 19 Juin 2007

Questions are:

How do we know this is due to human activities ?

If yes, what are the future projections.

Need climate models to answer these questionsEvry, 19 Juin 2007

Climate models

U

t 2 U .

1) Attribution Process

• other GHGs• aerosols• volcanic• solar• natural internal

Model

Historical forcing

Greenhouse gases Aerosols

NaturalTotal anthropogenic

Evry, 19 Juin 2007

Continental warming attribution

Fig. SPM-4

• Land vs. ocean contrast explained• Continental scale warming LIKELY due to increase in anthrop. GHG

Evry, 19 Juin 2007

IPCC future socio-economic scenarios

A1: A world of rapid economic growth and rapid introductions of new and more efficienttechnologies

A2: A very heterogenous world with an emphasis on familiy values and local traditions

B1: A world of „dematerialization“ and introduction of clean technologies

B2: A world with an emphasis on local solutions to economic and environmental sustainability

IS92a „business as usual“ scenario (1992)

5

Evry, 19 Juin 2007

IPCC future socio-economic scenarios

Evry, 19 Juin 2007

Future projections

Observed climate change in unequivocal

Very likely due to human activity

Depending on SRES scenario future climate change ranges from :

1.8 [1.1 – 2.9] to 4.0 [2.4 –6.4]

In summary Work towards IPCC AR 5

Lecture 7: Climate modelling activities, page 29CMIP5 model simulationsTwo classes of models to address two time frames and two sets of science questions

Near-Term (2005-2030) high resolution (perhaps 0.5°), no carbon cycle, some chemistry and aerosols, single scenarioScience question: e.g. regional extremes

Longer term (to 2100 and beyond) lower resolution (roughly 1.5°), carbon cycle, specified or simple chemistry and aerosols, benchmark stabilization concentration scenarios; Science question: e.g. feedbacks.

Lecture 7: Climate modelling activities, page 30

© Crown copyright Met Office

CMIP5 model simulations

6

Lecture 7: Climate modelling activities, page 31

Example NCAR

Lecture 7: Climate modelling activities, page 32

Example CCCma

Greg Flato

Lecture 7: Climate modelling activities, page 33

© Crown copyright Met Office

Socio-economic variables EmissionsSurface temperature

Socio-economic variables ConcentrationsSurface temperature

Forward approach: start with socio-economic variables

Reverse approach: start with stabilization scenario concentrations

Concentrations

Emissions

Representative Concentration Pathways (RCPs)Pre AR4 used forward approachAR5 will use reverse approach

mitigation costs implied emissions concentrations sensitivity impacts

Requires interpolating and scaling

Lecture 7: Climate modelling activities, page 34CO2 Emissions (World)

-5.000

0.000

5.000

10.000

15.000

20.000

25.000

30.000

2000

2005

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

RCP 8.5

RCP 2.6

RCP 4.5

RCP 6.0

Baselines

MtC

Source: van Vuuren et al., 2009

Lecture 7: Climate modelling activities, page 35 Lecture 7: Climate modelling activities, page 36

7

Lecture 7: Climate modelling activities, page 37 Lecture 7: Climate modelling activities, page 38

Lecture 7: Climate modelling activities, page 39 Lecture 7: Climate modelling activities, page 40