Stronger ENSO-induced global SST variability in a warming climate

The El Niño-Southern Oscillation (ENSO) is a leading mode of interannual climate variability with far-reaching global impacts. Understanding how ENSO-driven changes evolve in a warming climate is essential to project future climate variability. Here, we show that climate models robustly project an amplification of ENSO’s influence on global sea surface temperature (SST) under greenhouse warming. This amplification is primarily driven by two factors: changes in El Niño-induced surface wind speed and alterations in the climatological air-sea humidity difference. The former is linked to enhanced atmospheric teleconnections associated with ENSO, while the latter stems from an overall increase in global SST. Our findings suggest that future El Niño events may exert stronger regional climate impacts, not only through intensified atmospheric teleconnections but also by reinforcing local air-sea interactions. The authors show that El Niño’s influence on global sea surface temperatures is projected to intensify in a warming climate due to stronger wind-driven teleconnections and larger air-sea humidity differences.