Fig. 2: Model and proxy global mean temperature change relative to preindustrial.

Global mean true surface temperature (GMST) anomaly, ^l,p,eΔT^t in models and observations from five time periods. a post-1975, b Historical, c Last glacial maximum (LGM, ^l), d mid-Pliocene warm period (MPWP, ^p), and e early Eocene climatic optimum (EECO, ^e). Light grey circles show CMIP6/PMIP4 models with ECS in the very likely range as assessed by Forster et al.¹⁸; models in red have an ECS greater than the assessed very likely range (>5 °C); models in blue have an ECS lower than the assessed very likely range (<2 °C). Dark grey large circles show the multi-model ensemble mean for CMIP6/PMIP4. Dark grey small circles show the multi-model ensemble mean for CMIP5/PMIP3. Black circles and very likely ranges show the IPCC-assessed temperature anomaly derived from observations²⁶. For the LGM, the black open circle with a dashed very likely uncertainty range shows the GMST anomaly estimate from Annan et al. ³⁴. The historical anomaly in models and observations is calculated as the difference between 2005–2014 and 1850–1900, and the post-1975 anomaly is calculated as the difference between 2005–2014 and 1975–1984. For the LGM, MPWP and EECO, modelled temperature anomalies are compared with pre-industrial. The square symbol denotes the five simulations carried out by CESM2, and the triangle symbol denotes the three simulations carried out by CESM1.2. A version of this figure with all models labelled is in the Supplementary Information, Fig. S5, and all the models in this plot are listed in order of GMST in the Supplementary Information, Tables S1–S5. A similar plot of the paleo time periods, but also showing the site-specific metric, ^l,p,eΔT^s, is shown in Supplementary Information, Fig. S1.