Welcome to the Max Planck Institute for Meteorology

The Climate of the 21th century:New Model Projections for the

Intergovernmental Panel on Climate Change

Guy P. BrasseurMax Planck Institute for Meteorology

Hamburg

Flooding in Germany and in Prague in 2002

In summer 2003, an unprecedented heat wave in Western Europe.

Strong Tropical Hurricanes

Katrina2005

The Mission of the Max Planck Institute

for Meteorologyis

to understand how physical, chemical, and biological processes, as well as human behavior contribute to the dynamics of the Earth system, and specifically how they relate to global and regional climate changes.

These Objectives are realized though 3 MPI-M Departments:

• Ocean in the Earth System• (Director: Prof. Dr. Jochem Marotzke)

• Land in the Earth System• (Director: Prof. Dr. Martin Claussen;

up to 30 September: Prof. Dr. Hartmut Grassl)

• Atmosphere in the Earth System• (Director: Prof. Dr. Guy Brasseur)

MPI-M Earth System Model

HAMAerosols

HAMOCC5Ocean Bio-

geochemistry

JSBACHLand surface

MOZARTAtmospheric

Chemistry

MPI-OMOcean Physics

ECHAM5Atmospheric

Physics

The IPCC

• The Intergovernmental Panel on ClimateChange (IPCC) was set up in 1988 under the joint auspices the United Nations Environment Program (UNEP) and the WorldMeteorological Organisation (WMO) to analyse the potential effect of human activities on climate .

The 3 IPCC Groups

• Group I deals with the scientific aspects of climate change.

• Group II´s task is to examine the consequences ofclimate change, and to analyze our vulnerability to itand the measures that can be taken to adapt to it.

• Group III focuses on measures to reduce its effects.

The IPCC Report

• Three complete reports have been published (1990, 1995, 2001). The fourth report, which is inpreparation, is expected to be published in the fall of 2007

• The report of Group II includes 11 Chapters. The first draft is completed, and is currently under review by the international scientific community. The second draft will be reviewed in 2006 by the delegates of governmental bodies.

• A synthesis report and a summary for policy makers will be established.

pessimistic

optimistic

average

Input to Climate Models from Economic Scenarios

What do the MPI-M Models project for the End of the 21st Century?

• A general warming of the Earth of 2.5 to 4.0 C, depending on the adopted scenario for CO2 increase, but with large regional differences:

• In Europe: an increase of 3-4 degrees C (scenario A1B) or 2-3 degrees C (scenario B1)

• An ice-free summertime Arctic ocean after year 2090

What do the MPI-M Models project for the End of the 21st Century?

• A more active hydrological cycle (precipitations), but with large regional differences:• High Northern latitudes: warmer and wetter in winter• Southern Europe, Southern Australia, and South Africa:

dryer all year• Amazon, India and East Monsoon region: dryer in the dry

season, wetter in the wet season• Central Africa: wetter

• Europe: reduction of 10-50% in the precipitations, especially in the Mediterranean, wetter in Scandinavia.

What do the MPI-M Models project for the End of the 21st Century?

• More frequent extreme events:• In Europe, more numerous heat

waves, longer dry periods• In Europe, more intense

precipitation events• In the tropics, no significant

increase in the number of cyclones, but perhaps more intense hurricanes (this remains an open science question).

What do the MPI-M Models project for the End of the 21st Century?

• There is an important positive feedback between the carbon cycle and the climate system.

• In a warmer climate, more carbon is released to the atmosphere by the land biosphere and the ocean, leading to an additional warming.

Difference in carbon uptake between experiments(with minus without carbon cycle - climate feedback)

[kgC / m2]

positive feedback negative feedback

FeedbackAtmospheric CO2

MPI-M80 ppm

What do the MPI-M Models project for the End of the 21st Century?

• Aerosol particles play a key role in the climate system. An needed improvement in air quality is expected to accelerate global warming.

Surface air temperature

1950 2000 2050 2100Year

-0.5

0.0

0.5

1.0

1.5

2.0a) Precipitation

1950 2000 2050 2100Year

-1

0

1

2

3

4

5

6b)

Response of the climate system to a complete removal of anthropogenic sulphate aerosols in year 2000

Thank You

IPCC Scenario A1B with

ECHAM5/MPI-OM