evidence: Our results demonstrate that climate models as a group tend to underestimate the observed Arctic amplification in the 1979–2021 time period, i.e. since the beginning of the recent period of global warming. This is also true for the latest CMIP6 models despite the fact that some of these models better reproduce the absolute warming rate in the Arctic. However, those models that show plausible Arctic warming trend typically have too much global warming as well when compared to observations. In contrast, those models that simulate global warming close to that observed, generally have too weak Arctic warming (Fig. S9). Thus, our results show that most climate models are unable to simulate a fast-warming Arctic simultaneously with weaker global warming, as found earlier for the relationship of Arctic sea ice decline and global atmospheric warming34. Most strikingly the underestimation was true for the CMIP5 and MPI-GE ensembles, which altogether included only three realizations simulating as high AA as observed in 1979–2021. These results, i.e., lower AA in CMIP5 and CMIP6 models compared to the observations, are consistent with earlier studies38,40,41. [...] Fyfe, J. C., Gillett, N. P. & Zwiers, F. W. Overestimated global warming over the past 20 years. Nat. Clim. Change3, 767–769 (2013).