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 http://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 is only one run available. This run was initiated from the end of the corresponding 20C3M run of CCSR/NIES/FRCGC (the same resolution as this run, realization = 1). This run was forced by fixed external conditions for the year 2000, including solar and volcanic forcings, GHGs concentration, various aerosols emissions and land use. Model output data for CMIP3 in higher temporal resolutions and further variables are available in ESGF at https://esgf-node.llnl.gov/search/cmip3/.