Reduced spread of simulated global warming patterns among CMIP6 models with elevated level of warming

Abstract Uneven economic impacts of climate change have been largely caused by differentiated warming rates across different geographical regions, affecting the lives of the majority of world’s population. Historical and future warming rates are commonly obtained from global climate models, which exhibit considerable spread in terms of global mean and region-dependent warming rates. While the multi-model spread in global mean warming rate has been widely reported in past literature, the multi-model spread in terms of the global warming pattern and its temporal evolution remain unclear. Here, we show that the multi-model spread in the simulated global warming pattern depends closely on the level of warming. The simulated global warming pattern deviates substantially among CMIP6 models before the 2010s and converges afterwards, as the levels of global greenhouse gases and mean warming elevates. Moreover, the consistency of model-predicted future warming patterns varies by emission scenario. Models predict increasingly consistent warming patterns under intermediate and high emission scenarios during the entire 21st century; whereas under low emission scenarios, the multi-models consistency in their simulated future warming patterns reaches a hiatus around the middle of the 21st century. While our study detects a synchronism between the multi-model consistency in the global warming pattern and the global warming level, the physical mechanisms underlying such varying multi-model consistency in the warming pattern merits further investigation.