To develop and to improve global coupled ocean atmosphere climate models, to simulate the anthropogenic climate change using these models, and to diagnose the effect of the anthropogenic climate change as simulated by the models and to assess the uncertainties.


The present and future climate will be simulated with a hierarchy of global coupled ocean-atmosphere climate
models, which are developed at the different institutes participating in the project.
The use of different models and simulations carried out at the different institutes is essential in order to identify
the model dependency of the results, and also because the simulations are so costly that each institution can only
perform a limited number. Many experiments are needed to assess the variability and significance of the
simulations.
With these model experiments it will be investigated, how large the natural variability of the climate is and to
what extent mankind has already influenced the present day climate. It will be studied how the anthropogenic
emissions of greenhouse gases and aerosols will influence the future climate. This analysis will not only be
confined to primary quantities (like near-surface temperature change, sea level rise), but also to important
climate parameters, such as storm-frequency, hurricance frequency, daily temperature range, length and
frequency of droughts.
Furthermore, advanced statistical techniques will be employed to estimate, what degree of confidence can be
assigned to the model simulations, and to what extent observed climate variations can be tributed to
anthropogenic emissions or to natural fluctuations of the climate system (fingerprint analysis).
The project will give information about the future climate change and the reliability of this prediction.
Particular emphasis is placed on the intercomparison of the results from the different modelling groups
participating in this project. It will provide valuable input for regional modelling, for impact research and for
the planning of future observing systems (GCOS). Its results will enter the IPCC's climate change assessment
as well as the reports of similar national committees. The simulations will be compared not only with the results
of the other groups involved in this EC-project, but also with simulations done worldwide within the CLIVAR
and CMIP frameworks.