High emissions scenario climate models are “worst-case” scenarios used in ClimateFirst's data modelling. Climate models from the two most recent Coupled Modeled Intercomparison Projects, CIMP5 and CIMP6, are used. ClimateFirst uses the high emissions scenario from either CMIP5, RCP 8.5 or CMIP6, SSP-8.5, depending on which data is available at the site location. Both high emission scenarios, RCP8.5 and SSP5-8.5, exhibit approximately the same increase in radiative forcing (global warming) by the end of century, with the difference being the contributing sources for the GHG emissions associated with each pathway.