A new study has found that the strong El Niño events of 2014–2016 and 2023–2024 both contributed to increases in global mean sea level with water moving from land to the oceans accounting for most of the rise.
Researchers found that global average sea level increased by about 9.16 mm during the 2014–2016 El Niño development phase and 7.70 mm during the 2023–2024 event. Terrestrial water storage changes accounted for around 68% of the earlier rise and 81% of the later increase.
The 2023–2024 El Niño produced a faster rise over a shorter period, while warmer ocean water, particularly in the Indian Ocean, also contributed to sea level changes. Scientists linked this regional effect partly to the simultaneous positive Indian Ocean Dipole.
The study also found that differences in rainfall and water storage across Africa, North America and South America played an important role in determining how much water ultimately reached the oceans.
Meanwhile, scientists are closely watching the El Niño that has formed in 2026. NOAA forecasts an 81% probability of a very strong El Niño between October and December, with Niño 3.4 temperatures potentially exceeding 2°C above average.
A strong 2026 El Niño could therefore contribute to another period of rapid sea level rise while also pushing global temperatures higher, potentially increasing the risk of a new global temperature record.