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 are 5 ensemble runs available. This model run continues from the end of the 20th century simulation with aerosol loadings held constant at their year 2000 values, and GHG concentrations fixed at: CO2=367ppm, CH4=1760ppb, N2O=316ppb, CFC11=267pptr, CFC12=535pptr Model output data for CMIP3 in higher temporal resolutions and further variables are available in ESGF at https://esgf-node.llnl.gov/search/cmip3/.