El Niño is a natural climate phenomenon in which sea surface temperature and winds in the tropical Pacific periodically change, affecting global temperature and precipitation. Provided by Getty Images Bank
A forecast has been issued for a ‘super El Niño’ that will have a major impact on Earth’s climate. It predicts that, under the influence of El Niño, global temperatures in 2027 could break all previous records.
On the 23rd (local time), the international journal Nature examined how this year’s El Niño is developing and the impacts that are expected.
El Niño is a natural climate phenomenon in which sea surface temperature and winds in the tropical Pacific periodically change. It is declared when sea surface temperatures in a specific monitoring region of the central and eastern equatorial Pacific remain at least 0.5°C above the long-term average for more than five consecutive months. “Super El Niño” is an informal term used to describe an extremely strong El Niño.
Typically, warm El Niño events and cool La Niña events alternate every two to seven years. La Niña is the phenomenon in which sea surface temperatures in the eastern equatorial Pacific cool, opposite to El Niño.
This year’s El Niño formed in June and has been strengthening rapidly. The U.S. National Oceanic and Atmospheric Administration (NOAA) estimates there is an 80% chance that it will develop into a “very strong” El Niño by the end of the year. Combining projections from 14 climate models suggests that the peak sea surface temperature in the tropical Pacific during this El Niño could be about 0.8°C higher than the previous record set by the 2015–2016 El Niño.
If the super El Niño projections materialize, the vast amount of heat released from the ocean by El Niño could combine with human-induced global warming to make 2027 the hottest year ever recorded.
At the 2015 Paris Agreement (COP21), the upper limit for the increase in global average temperature was set at within 1.5°C above the pre-industrial average for 1850–1900. In 2024, the global average temperature already exceeded this threshold, reaching 1.55±0.13°C.
Zeke Hausfather, a climate scientist at the U.S. nonprofit research organization Berkeley Earth, said, “Because of the impact of this El Niño, it is not impossible for the global average temperature in 2027 to be up to 1.7°C higher than the pre-industrial average.” In other words, on an annual average basis, Earth’s temperature could set a new record.
A powerful El Niño can, depending on the region, intensify heatwaves, droughts, floods, wildfires and marine heatwaves, and trigger coral bleaching while reducing carbon uptake in terrestrial and marine ecosystems.
Justin Mankin, a professor at Dartmouth College in the United States, previously estimated that the strong El Niño of 1997–1998 led to a loss in subsequent global economic growth amounting to 5.7 trillion dollars (about 8,359 trillion won). He analyzed that if this El Niño unfolds close to current projections, it could cause economic losses of 10 trillion dollars (about 14,667 trillion won) by 2032.
It is difficult to conclude that this El Niño will be the largest in Earth’s history. Paleoclimate records indicate there may also have been a very strong El Niño in the 17th century.
The emergence of an extremely powerful El Niño immediately following the 2023–2024 El Niño just two years ago is unusual, but experts say it is still too early to conclude that human-driven warming is causing El Niño events to occur more frequently and with greater intensity.
– doi.org/10.1038/d41586-026-02293-y
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