In support of the fifth IPCC-AR5 (Intergovernmental Panel for Climate Change Assessment Report 5), the ACCMIP historical emissions dataset has been developed (Lamarque et al, 2010), together with the emissions projections of the so-called RCPs (Representation Concentration Pathways), described in van Vuuren et al., 2010. During the past few years, a community effort led to the development of the ACCMIP emissions, a dataset of monthly, sectoral, gridded anthropogenic and biomass burning emissions covering the historical period (1850-2000) (Lamarque et al, 2010); the RCP projections of future emissions (Representative Concentration Pathways) are based on selected scenarios from four independent modeling teams/models. The primary purpose of the ACCMIP inventory and the RCPs is to provide consistent gridded emissions of reactive gases and aerosols for use in chemistry model simulations needed by climate models for CMIP5. The year 2000 was chosen as the reference year, since ACCMIP 2000 emissions represent a combination of the best information available from existing regional and global inventories in the years 2008-2009 when the inventory was built. For anthropogenic sectors, 40 regions and 12 sectors were used to combine the various sources. Both the historical reconstruction of each emitted compound and RCPs future emission trends were then forced, as an handshake requirement, to agree with the 2000 estimate, ensuring continuity between past, 2000 emissions and future projections. The RCPs emissions were developed by four modeling teams. Each of them applied a set of algorithms to ensure consistency with the 2000 emission inventory. The RCPs are named according to their 2100 radiative forcing level, i.e. RCP 8.5 corresponds to a radiative forcing of 8.5 W.m-2 in 2100. A documentation for each of the four RCPs is available at: http://www.iiasa.ac.at/web-apps/tnt/RcpDb