projections obtain under the RCP scenarios are analysed against the backdrop of various SSPs. As several emission updates were due, a new set of emission scenarios was developed in conjunction with the SSPs. Hence, the F abbreviation SSP is now used for two things: On the one hand SSP1, SSP2, ..., SSP5 is used to denote the five socio-economic r scenario families. On the other hand, the abbreviations SSP1-1.9, e SSP1-2.6, ..., SSP5-8.5 are used to denote the newly developed to emission scenarios that are the result of an SSP implementation within an integrated assessment model. Those SSP scenarios F are bare of climate policy assumption, but in combination with D so-called shared policy assumptions , various approximate radiative forcing levels of 1.9, 2.6,..., or 8.5 W m² are reached by F the end of the century, respectively.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report