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. – , 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. – , 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. – , Hong Kong Climate of the last years (Vostok ice core) we are here

Cubasch and Huebener, ICCC 29. – , 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. – , Hong Kong Krakatoa Pinatubo Agung El Chichon solar volcanoes volcanoes + solar St. Maria Makian Natural forcings selected red: solar, yellow: volcanoes, green: solar and volcanoes

Cubasch and Huebener, ICCC 29. – , Hong Kong The AR4 modelling results natural and anthropogenic forcing natural forcing observations

Cubasch and Huebener, ICCC 29. – , Hong Kong ENSEMBLES 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. – , 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. – , Hong Kong Annual temperature changes (K) A1b

Cubasch and Huebener, ICCC 29. – , Hong Kong Annual mean surface air temp. change (K) for all the scenarios rel. to 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. – , Hong Kong DJF precipitation change (mm/d) A1B

Cubasch and Huebener, ICCC 29. – , 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 rel. to

Cubasch and Huebener, ICCC 29. – , 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. – , 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. – , Hong Kong Comparison ENSEMBLES with AR4 Projected warming in 21st century patterns quite similar. Magnitude of change smaller in ENSEMBLES than in IPCC AR4 IPCC AR4C ENSEMBLES

Cubasch and Huebener, ICCC 29. – , Hong Kong ENSEMBLES Projected precipitation change patterns quite similar AR4 mm/d Comparison ENSEMBLES with AR4

Cubasch and Huebener, ICCC 29. – , Hong Kong PartnerIPSLMPIDMI CNRM (Meteo) FUBHadleyCent.NERSC Model IPSL- CM4 ECHA M5/ MPI- OM CNRM- CM3 EGMA M HadGEM 1 HadC M3 ARPEGE V3 / MICOM + OASIS Atmosphere component LMDZ-4 ECHA M 5 ARPEG E V3 ECHA M4-MA HadGAM 1 ARPEGE V3 resolution (top level) 2.5°x3.7 5° L19 (10hPa) T63 L31 (10hPa ) T63 L31 (10hP a) T63 L45 (0.05hP a) T30 L39 (0.01h Pa) 1.25°x1.8 8° L38 (3.1hPa) T42 L19 (10hP a) T63 L31 (10hPa) ocean component OPA 8.1 MPI- OM OPA 8.1 HOPE- G HadGOM 1 NERSC modif. MICOM2.8 resolution 2° part. refined L31 1.5° L40 1.5° L40 2° part. refined L31 T42 equat. refined L20 1° equat. refined L ° L20 1.5° equat. refined L35 The ENSEMBLES-Partners and their Models

PartnerIPSLMPIDMI CNRM (Meteo) FUBHadleyCent.NERSC 20C3M anth.yesyes (3x)yes yes (3x)yes 20C3M anth.+natyes (2x)yes(3x)yes A1Byesyes (3x)yes yes (3x)yes 750 ppm stab.yesyes (2x)yes yes (3x) yes B1yesyes (3x)yesyes (3x) Spring ´07 yes 550 ppm stab.yesyes (3x)yesyes (2x) yes A2yesyes (3x)yesyes (3x)yes 835 ppm stab. yes 1% CO 2 until doubling (CMIP) yesyes (3x)yes yes (+300y) yes 1% CO 2 until 4x, then fixed yes Current status of model experiments

Outlook “second stream” simulations have to conform to the IPCC AR5

Cubasch and Huebener, ICCC 29. – , Hong Kong Atmosphere sea-ice Land-surface Aerosols Land and ocean carbon cycle Dynamic vegetation Earth System Model Off-line impacts On-line impacts Without downscaling Impact models AOGCM Downscaling and embedded regional models Ocean Chemistry The comprehensive Earth-System-Model first stream second stream?

Cubasch and Huebener, ICCC 29. – , 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