El Niño–Southern Oscillation (ENSO) predictability in equilibrated warmer climates

Abstract. Responses of El Niño–Southern Oscillation (ENSO) to global warming remain uncertain, which challenges ENSO forecasts in a climate. We investigate changes characteristics and predictability idealized simulations with quadrupled CO2 forcing from seven general circulation models. Comparing the warmer climate control simulations, variability weakens, neutral state lasting longer, while active states last shorter skew favor La Niña state. The 6-month persistence-assessed slightly reduces five models increases two under condition. While overall are insignificant, we find significant relationships between intensity, duration, skewness three individual states. maximal contribution Niño, stems events' duration. Our findings show that robust decrease does not imply similar change This could be due model deficiencies dynamics limitations persistence when predicting ENSO.