These data represent monthly averaged values of selected variables for the Data Distribution Centre (DDC) of the Intergovernmental Panel on Climate Change (IPCC). (see also https://www.ipcc-data.org/) The model output prepared for IPCC Fourth Assessment committed climate change experiment (COMMIT). These datasets are available in netCDF and GRIB format. For this experiment there are 3 ensemble runs available. This simulation was initiated from year 1980-03 of PCM1 model run B06.08 and executed on hardware blackforest.ucar.edu. Physical constants used for derived data: Lv (latent heat of evaporation): 2.501e6 J kg-1 Lf (latent heat of fusion ): 3.337e5 J kg-1 r[h2o] (density of water ): 1000 kg m-3 Model output data for CMIP3 in higher temporal resolutions and further variables are available in ESGF at https://esgf-node.llnl.gov/search/cmip3/.