Modulation of the Arctic–East Asian winter teleconnection by extreme CO₂ forcing

Abstract The winter warm Arctic–cold East Asia (WACE) pattern is linked to Arctic sea-ice loss and internal variability. It remains unclear how the interannual Arctic–East Asian teleconnection will change in the future. Using CMIP6 multi-model simulations, we examine whether this teleconnection persists or breaks down under extreme CO₂ forcing. Multiple analyses reveal a weakening of the Arctic–East Asian teleconnection from pre-industrial levels to 4×CO₂, and a recovery under CO₂ removal. Under 4×CO₂, the thermodynamical (e.g., meridional temperature gradient) and dynamical (e.g., Rossby wave activity) pathways linking Arctic warming to midlatitude climate are significantly weakened. This is attributed to a less effective sea-ice–turbulent heat flux feedback in a warmer climate, which has a weaker capacity to amplify Arctic warming under 4×CO₂. The results highlight the modulation of the WACE teleconnection by extreme CO₂, affecting the reliability of Arctic signals for anticipating future East Asian winter climate.