where ‘SSPx’ refers to the Shared Socio-economic Pathway or ‘SSP’ describing the socio-economic trends 
underlying the scenario, and ‘y’ refers to the approximate level of radiative forcing (in watts per square metre, or Wm–2) resulting from the 
scenario in the year 2100.
** The AR5 scenarios (RCPy), which partly inform the AR6 WGI and WGII assessments, are indexed to a similar set of approximate 2100 radiative 
forcing levels (in W m-2). The SSP scenarios cover a broader range of GHG and air pollutant futures than the RCPs. They are similar but not 
identical, with differences in concentration trajectories for different GHGs. The overall radiative forcing tends to be higher for the SSPs compared 
to the RCPs with the same label (medium conﬁdence). {WGI TS.1.3.1}
*** Limited overshoot refers to exceeding 1.5°C global warming by up to about 0.1°C, high overshoot by 0.1°C-0.3°C, in both cases for up to 
several decades.