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 SRES A1B experiment. For this experiment there is only one run available. SRES A1B experiment with CSIRO Mk 3.0 model, starting from year 2000 (model year 250) of 20C3M experiment. Radiative forcings held constant from year 2100. For model output data in higher temporal resulution and more variables visit the web page https://esg.llnl.gov:8443/home/publicHomePage.do.