In support of the IPCC, the international climate research community has launched a comparison project known as the Coupled Model Intercomparison Project 5 (CMIP5). In this project, coordinated experiments with climate and Earth system models were organized in order to research and answer questions regarding the mechanisms and characteristics of climate change. As a German contribution to CMIP5 and the Fifth IPCC Assessment Report, which will be published in 2013/2014, extensive scenario simulations have been carried out by the DKRZ and the Max-Planck-Institute for Meteorology (MPI-M) starting in 2010. Certain topics studied in the project include:

  • Baseline experiments, such as for the time period between 1850 and 2005
  • Projections for particular scenarios spanning until 2100 and 2300
  • Decadal climate predictions
  • Role of the carbon cycle in climate change
  • The more distant past, for example the years 850-1850 or the last glacial maximum

The standardized experiments regarding these topics were carried out worldwide by nearly 20 climate modeling groups using the newest climate and Earth system models. Here you will find information on the experiments carried out in Hamburg.

The Model - MPI-ESM

The CMIP5 simulations were carried out by DKRZ and the Max Planck Institute for Meteorology (MPI-M) using the new Earth system model MPI-ESM, developed by the MPI-M.

The RCP Scenarios

With respect to the Fifth IPCC Assessment Report, a new set of scenarios was defined in order to take into account the rising complexity of model calculations and analyze the effect of different political measures.


The extensive simulations, which were carried out with the Earth system model MPI-ESM with respect to the CMIP5 project and the IPCC AR5, are key to numerous scientific projects for the years to come. By presenting a selection of visualizations for different key climate variables and for the different scenarios, we show the possible bandwidth of future climate changes.

Data Access

About 650 terabytes of raw data was produced at DKRZ during the CMIP5/IPCC AR5 simulations with MPI-ESM. A total of 60 terabytes, a subset of the most important variables, was extracted and made available to the worldwide climate research for further investigation. Here you can learn more about experiments that were carried out, available data, and their accessibility.