Synergies Between Observed Warming and ENSO Episodes on Extreme Events

ABSTRACT
El Niño/Southern Oscillation (ENSO) is the dominant interannual variability mode of the global climate system with significant effects on a variety of weather conditions, including extremes. Past events illustrate the severe societal consequences this phenomenon has through weather disasters, food security, health, economic growth, migration, and conflict. ENSO’s interactions with global warming are not well understood, although they can lead to significant changes in the characteristics of extreme events. Climate conditions in 2024/2025 may favor widespread severe extreme events with global temperature anomalies nearing or surpassing 1.5°C and a transition from strong El Niño to La Niña conditions. Here, we show that current warming has amplified the effects of ENSO on temperature and precipitation extremes worldwide. Results show that warming has produced a considerable amplification of the effects of ENSO episodes over such extremes, as well as extensively modified spatial patterns. We show that considerable shares of the population, gross domestic product, agriculture, and ecosystems now face a higher risk from extreme events due to the interactions between increased anthropogenic forcing and ENSO.

https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/nyas.70122