Speeding extreme cold events under global warming

Abstract Regional anthropogenic warming caused stronger and shorter cold events in the winter (December–February) of 2020–21, with the strongest cooling of −10 °C covering an area of 1.63 × 10 7 km 2 over East Asia. In contrast to previous cold events, the extreme cold events in 2020–21 were a result of meridional circulation change due to stronger regional anthropogenic warming. Our results show a multi-aspect anthropogenic effect in the process of cold events, and illustrate that anthropogenic effect played a role not only in the thermodynamic process but also in the dynamic process. The exchange of equilibrium from low to high index does not take fewer cold events anymore; new principles on equilibrium have appeared and will soon play an effect in more fields of climate change.