We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups (listed in Supplementary Table 3) for producing and making available their model output. For CMIP, the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provided coordinating support and led development of the software infrastructure in partnership with the Global Organization for Earth System Science Portals. We thank K. Taylor, G. Schmidt and R. Pincus for discussions. K.M. and C.J.W.B. were supported by the US Department of Energy Biological and Environmental Research Grant DE-SC0014423. K.M., B.I.C. and A.P.W. were supported for this work by the NASA Modeling, Analysis, and Prediction program (NASA 80NSSC17K0265). J.E.S. was supported in part by US National Science Foundation (NSF) grants AGS-1243204 and AGS-1602581; J.E.S. and A.P.W. were further supported by NSF grant OISE-1743738 and A.P.W. was supported by NSF grant AGS-1703029. P.J.D. was supported through PCDMI SFA funding from the DOE Regional and Global Model Analysis Program. Work at LLNL was performed under the auspices of the US Department of Energy under contract DE-AC52-07NA27344.

Reviewer information

Nature thanks Hans Linderholm and the other anonymous reviewer(s) for their contribution to the peer review of this work.