The CSIRO Mk 3.0 climate system model contains a comprehensive representation of the four major components of the climate system (atmosphere, land surface, oceans and sea-ice). There are a simulations for a range of scenarios available for this model and also for the later CSIRO Mk 3.5 model. This simulation uses scenario 1pctto2x which represents a 1%/year CO2 increase to doubling. This is a standard experiment for model intercomparisons. The scenario includes standard daily and monthly meteorological, and monthly oceanographic variables as netCDF files organised by variable and time period, totalling 700 files. The data are accessible to authorised users via an OpenDAP server at CSIRO HPSC, and also from PCMDI in the U.S.A. It is also a contribution to the WCRP CMIP3 multi-model database and meets their formatting standards.