Project: IPCC Data Distribution Centre : Fourth Assessment Report data sets - The Intergovernmental Panel on Climate Change (IPCC) has been established by WMO and UNEP to assess scientific, technical and socio-economic information, relevant for the understanding of climate change, its potential impacts and option for adaption and migration. Projection of future trends for a number of key variables are provided through this section of the DDC (http://ipcc-data.org/sim/gcm_clim/SRES_AR4 ). The SRES scenarios have been constructed to explore future developments in the global enviromental with special reference to the production of greenhouse gases and aerosol precursor emission. A set of four scenario families (A1, A2, B1, B2) have been developed that each of this storylines describes one possible demographic, polito-economic, societal and technological future. Model experiments, also using different forcing scenarios, were calculated at other modeling centres. The data represent a subset of data sets from the IPCC Model Output Archive at PCMDI (https://pcmdi.llnl.gov/mips/cmip3/). _ These datasets are available in netCDF and GRIB format. The dataset names are composed of - centre/model acronym (e.g. MPEH5: Max-Planck-Institute/Echam5) - scenario acronym (e.g. SRB1: SRES B1) - run number (e.g. 1: run 1) - format identifier (e.g. N: netCDF, G: GRIB) - variable acronym [with level value] (e.g. hur850: relative humidity, 850 hPa) --> example: MPEH5_SRB1_1_G_hur850 Summary: HadEX is a global land-based climate extremes dataset produced through the coordination of the joint WMO CCl/CLIVAR Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). It comprises of 27 indices of temperature and precipitation on a 2.5deg x 3.75deg grid from 1951 to 2003. The indices represent seasonal and/or annual values derived from daily station data. Data are calculated using RClimDex/FClimDex software; developed and maintained on behalf of the ETCCDMI by the Climate Research Branch of the Meteorological Service of Canada (http://cccma.geos.uvic.ca/ETCCDMI/) The full description can be found at http://www.hadobs.org/