21st century climate change as simulated by European

climate models

U. Cubasch, H. Huebener

Thanks to: F. Niehörster, I. Fast, T. Spangehl

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

The climate system

Physical system, components interacting on different time and space scales use physical equations to describe and simulate the system!

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

What is the scale? Years? Million years?

Global warming since 19th century: anthropogenic signature or natural fluctuations?

Put measured signal in the geological perspective

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Climate of the last 400 000 years (Vostok ice core)

we are here

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Temperature-Reconstruction (treerings, corals, ice and sediment cores, historical evidence) of northern

hemisphere temperature from year 1000 to 1999 and instrumental records from 1902 to 1999

„Mann et al“- curve (Hockey-Stick)

Zoom in on last 1000 years (note: change of abscissa)

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Solar constant and modified solar constant (anomaly relative to 1850-2000)

-20.00

-15.00

-10.00

-5.00

0.00

5.00

1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

KrakatoaPinatubo

AgungEl Chichon

solar

volcanoesvolcanoes + solar

St. MariaMakian

Natural forcings selectedred: solar, yellow: volcanoes, green: solar and

volcanoes

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

The AR4 modelling results

natural and anthropogenic forcing

natural forcing

observations

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

ENSEMBLESwww.ensembles-eu.org

The project aims to: • Develop an ensemble prediction system for climate change of

state-of-the-art, high resolution, global and regional Earth System models developed in Europe, to produce an objective probabilistic estimate of uncertainty in future climate at the seasonal to decadal and longer timescales

• Quantify and reduce the uncertainty in the representation of physical, chemical, biological and human-related feedbacks in the Earth System (including water resource, land use, and air quality issues, and carbon cycle feedbacks)

• Maximise the exploitation of the results by providing the outputs to a applications e.g. in agriculture, health, food security, energy, water resources, insurance and weather risk management

• 76 participants, managed by the Hadley Centre (UK)

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

The ENSEMBLES project

• EU-project, contributing to IPCC AR4

• 7 European AO-GCMs: – HadCM3 (UK)– HadGEM1 (UK)– ECHAM5/MPI-OM (Germany, Denmark)– CNRM-CM3 (France)– IPSL-CM4 (France)– BCM2 (Norway)– EGMAM (Germany)

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Annual temperature changes (K) A1b

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Annual mean surface air temp. change (K) for all the scenarios2080-2099 rel. to 1980-1999• Strongest warming in high northern latitudes and over continents• Weakest warming over southern hemisphere oceans• ENSO-like warming pattern in tropical Pacific in A1b and A2 scenario• SE-Asia: warming > 4°C (in A2), > 3°C (in A1b), > 2°C (in B1)

A1b A2

B1

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

DJF precipitation change (mm/d) A1B

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

mm/d

Precipitation change A1b scenario

• Largest changes where absolute values are largest (Tropics!)

• General increase in Tropics, mid to high latitudes• Decrease in subtropics• Differences in regional trends between models• South China Sea: decrease in DJF, increase in JJA

Precipitation change (mm/day), ensemble mean 2080-2099 rel. to 1980-1999

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Summary I• ENSEMBLES 20th century simulations

quite similar to each other and to observations, if both, natural and anthropogenic forcing are included.

• IPCC scenarios A2, A1b and B1 have been run by 7 modeling groups. However, sample size per group is still small (≤ 4)

• Temperature and precipitation change patterns similar for all the models and to the one in both IPCC reports (2001, 2007)

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

• Warming in all models and all scenarios, largest in high northern latitudes and over continents, smallest over southern oceans

• Mean values for the year 2100 relative to 2000: 2.6 K for A1b, 3.4 K for A2 and 1.5 K for B1 lower than in the AR4 report for all scenarios

• Global precipitation rise, but distinct regional patterns, less consistency among models

Summary II

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Comparison ENSEMBLES with AR4

Projected warmingin 21st century patterns quite similar. Magnitude of change smaller in ENSEMBLES than in IPCC AR4

IPCC AR4CENSEMBLES

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

ENSEMBLES

Projected precipitation change patterns quite similar

AR4

mm/d

Comparison ENSEMBLES with AR4

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Partner IPSL MPI DMICNRM

(Meteo)FUB Hadley Cent. NERSC

ModelIPSL-CM4

ECHAM5/ MPI-OM

ECHAM5/ MPI-OM

CNRM-CM3

EGMAM

HadGEM1

HadCM3

ARPEGE V3 / MICOM +

OASIS

Atmosphere component

LMDZ-4ECHAM 5

ECHAM 5

ARPEGE V3

ECHAM4-MA

HadGAM1

  ARPEGE V3

resolution (top level)

2.5°x3.75° L19 (10hPa)

T63 L31

(10hPa)

T63 L31

(10hPa)

T63 L45

(0.05hPa)

T30 L39

(0.01hPa)

1.25°x1.88° L38

(3.1hPa)

T42 L19

(10hPa)

T63 L31(10hPa)

ocean component

OPA 8.1MPI-OM

MPI-OM

OPA 8.1HOPE-

GHadGOM

1 

NERSC modif. MICOM2.8

resolution

2°part.

refinedL31

1.5° L40

1.5° L40

2° part.

refined L31

T42 equat.

refined L20

1°equat.

refined L40

1.25°L20

1.5°equat. refined

L35

The ENSEMBLES-Partners and their Models

Partner IPSL MPI DMICNRM

(Meteo)FUB Hadley Cent. NERSC

20C3M anth. yes yes (3x) yes yes yes (3x) yes yes yes

20C3M anth.+nat yes (2x) yes(3x) yes

A1B yes yes (3x) yes yes yes (3x) yes yes yes

750 ppm stab. yes yes (2x) yes yes yes (3x)   yes  

B1 yes yes (3x) yes yes (3x)Spring

´07yes yes

550 ppm stab. yes yes (3x) yes yes (2x)   yes  

A2 yes yes (3x) yes yes (3x) yes yes yes

835 ppm stab.       yes      

1% CO2 until doubling (CMIP)

yes yes (3x) yesyes

(+300y)yes   yes

1% CO2  until 4x, then fixed

yes yes yes yes yes   yes

Current status of model experiments

Outlook

“second stream” simulationshave to conform to the

IPCC AR5

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Atmosphere

sea-ice

Land-surface

Aerosols

Land and ocean carbon cycle

Dynamic vegetation

Earth SystemModel

Off-line impacts

On-line impacts

Withoutdownscaling

Impact models

AOGCMDownscaling

and embeddedregionalmodels

Ocean

Chemistry

The comprehensive Earth-System-Model

first streamsecond stream?

Cubasch and Huebener, ICCC 29. – 31. 5. 2007, Hong Kong

Outlook: ENSEMBLES ‘second stream’ models

The models will probably include:• dynamic vegetation• carbon cycle• aerosols (in differing complexity)

• The models should be suitable for realizing more than one run