To explore and investigate climate futures, climate change projections are developed using sets of different input projections. These consist of sets of projections of GHG emissions, aerosols or aerosol precursor emissions, land use change, and concentrations designed to facilitate evaluation of a large climate space and enable climate modelling experiments. For AR5  5 climate model experiments), the input projections were referred to as representative concentration pathways . For AR6 , new sets of inputs are used and referred to as SSP scenarios, where SSP refers to socioeconomic assumptions called the shared socioeconomic pathways .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report