Enhanced Trans‐Seasonal ENSO Impact on East Asian‐Western Pacific Climate in Warmer Future: An Emergent Constraint From Multi‐Large Ensembles

Abstract Predicting the boreal summer climate over East Asia and the western Pacific is crucial for communities preparing for extreme events. A key source of predictability is the strong connection between the western North Pacific anomalous circulation (WNPAC) and the preceding El Niño‐Southern Oscillation (ENSO). However, the potential change of this link under future greenhouse warming remains uncertain due to substantial internal variability and inter‐model discrepancies. Here, by leveraging emergent constraints from multi‐large ensemble simulations, we show that the trans‐seasonal ENSO‐WNPAC correlation robustly strengthens under high‐emission scenarios, with a 67% reduction in the projection uncertainty. This enhancement indicates a 9% increase in the ENSO‐contributed predictability (explained variance) of summer WNPAC. The spread across models primarily derives from their differing representations of ENSO‐decaying regimes. Our results indicate a more predictable East Asian‐western Pacific summer climate in a warmer world, offering encouraging prospects for adapting to anticipated increases in extremes associated with WNPAC.