Very early warning of a moderate-to-strong El Niño in 2023

Abstract

The El Niño Southern Oscillation (ENSO) is the strongest driver of year-to-year variations of the global climate and can lead to extreme weather conditions and disasters in various regions around the world. Here, we review two different approaches for the early forecast of El Niño that we have developed recently: the climate network-based approach allows forecasting the onset of an El Niño event about 1 year ahead, while the complexity-based approach allows additionally to estimate the magnitude of an upcoming El Niño event in the calendar year before. For 2023, both approaches predict the onset of an El Niño event, with a combined onset probability of about 89%. The complexity-based approach predicts a moderate-to-strong El Niño with a magnitude of $1.49\pm 0.37$°C. Since El Niño events temporarily increase the global temperature, we expect that the coming El Niño will increase the global temperature by about +0.2°C, likely making 2024 the hottest year since the beginning of instrumental observations. It is possible that as a consequence of this El Niño, the +1.5°C target (compared to pre-industrial levels) will be temporarily breached already in 2024.

11 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:2102.02192; text overlap with arXiv:2212.14025