abrupt4xco2 is an experiment of the CMIP5 - Coupled Model Intercomparison Project Phase 5 ( https://pcmdi.llnl.gov/mips/cmip5 ). CMIP5 is meant to provide a framework for coordinated climate change experiments for the next five years and thus includes simulations for assessment in the IPCC AR5. This subset of the CMIP5 additional historical data were collected by ETH Zurich until 15th March 2013 in support of IPCC AR5 Working Group 1 ( http://wiki.c2sm.ethz.ch/COSMO/CMIP5 ). These data are part of the IPCC-DDC AR5.

                abrupt4xco2 (6.3 Abrupt 4XCO2) - Version 2: Impose an instantaneous quadrupling of CO2, then hold fixed.

                Experiment design: https://pcmdi.llnl.gov/mips/cmip5/experiment_design.html 
                List of output variables: https://pcmdi.llnl.gov/mips/cmip5/datadescription.html 
                Output: time series per variable in model grid spatial resolution in netCDF format
                Earth System model and the simulation information: CIM repository

                Data are structured and entry names are set according to the ETH Zurich Archive layout: "experiment/MIP table/variable/model/ensemble member/CMOR filename.nc"