Downscaling MAGICC Warming Signals over Space

This paper develops a method for calculating NGFS-consistent regional warming projections. Starting from the benchmark NEX-GDDP dataset, outputs are transformed into annual anomalies for approximately 3,600 GADM level-1 regions and matched to global CMIP6 anomalies by year, SSP–RCP pathway, and parent GCM across a subset of 12 likely models. 

About 173,000 no-intercept polynomial functions are estimated, and GCM-specific parameters are used to assess regional uncertainty envelopes. The resulting region-level parameters, or transfer functions, are applied to NGFS scenario–IAM GSAT trajectories emulated by MAGICC, yielding regional warming signals that 

(i) preserve the geographic structure of NEX-GDDPCMIP6 while 

(ii) mapping differences across global NGFS trajectories into spatially coherent amplification or attenuation of warming intensities. 

Regional warming signals are ultimately rebased to the 1850–1900 average and aggregated at the country level, with weighted variants for ingestion into downstream macro-climate applications. 

Keywords: Climate scenarios; CMIP6; NEX-GDDP; NGFS; MAGICC; regional climate pattern scaling.