Downscaling and geo-spatial gridding of socio-economic projections from the IPCC Special Report on Emissions Scenarios (SRES)

Abstract

A database has been developed containing downscaled socio-economic scenarios of future population and GDP at country level and on a geo-referenced gridscale. It builds on the recent Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES), but has been created independently of that report. The SRES scenarios are derived from projected data on economic, demographic, technological and land-use changes for the 21st century in a highly aggregated form consisting of four world regions. Since analysts often need socio-economic data at higher spatial resolutions that are consistent with GCM climate scenarios, we undertook linear downscaling to 2100 of population and GDP to the country level of the aggregated SRES socio-economic data for four scenario families: A1, A2, B1, B2. Using these country-level data, we also generated geo-spatial grids at 1/4° resolution (∼30km at the equator) for population “density” (people/unit land area) and for GDP “density” (GDP/unit land area) for two time slices, 1990 and 2025. This paper provides background information for the databases, including discussion of the data sources, downscaling methodology, data omissions, discrepancies with the SRES report, problems encountered, and areas needing further work.