UN issues sobering warning about looming El Niño
World leaders are especially concerned with the prospect of droughts, heavy rainfall events and heat waves, which are expected to happen unevenly across the globe.
A new warning was issued on June 2 about the looming El Niño climate pattern.
The World Meteorological Organization (WMO), the United Nations' weather agency, said there's an 80% likelihood of an El Niño event starting this summer.
The prospect of a strong El Niño raises fears of additional heat, including marine heat waves, piling on top of long-term climate warming. Forecasts are raising alarms globally because of the pattern's powerful influence over the world's weather, and a strong event could create ripple effects for months to come.
Fueled by unusually warm ocean waters in the tropical Pacific, the WMO said El Niño conditions are developing and set to influence global temperature and rainfall patterns.
Beyond this summer, probabilities for El Niño to continue until at least November are near or above 90%. Although some uncertainty remains about El Niño's peak strength and timing, most forecast models suggest it will be at least moderate – and possibly strong, the WMO said in a statement.
El Niño occurs when sea-surface temperatures in the central Pacific Ocean are above average. The natural climate pattern affects weather worldwide.
“The science is clear: El Niño is arriving on our doorstep in the coming months with 90% certainty," said United Nations Secretary-General António Guterres, in a video statement. "The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world.
"Impacts will hit even harder, travel even farther, and cross borders with devastating speed,” he said.
Prepare for a 'strong' El Niño
Scientists say this could be a very strong El Niño, potentially a "Super" El Niño, which is not an official term used by the WMO or the National Oceanic and Atmospheric Administration (NOAA).
“We need to prepare for a potentially strong El Niño event — which will exacerbate drought and heavy rainfall and increase the risk of heat waves both on land and in the ocean," said WMO Secretary-General Celeste Saulo, in a statement. "The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024.”
According to the WMO, El Niño is typically associated with increased rainfall in parts of southern South America, the southern United States, the Horn of Africa and central Asia, and drought over Australia, Indonesia and parts of southern Asia.
What is El Niño?
El Niño is a natural climate pattern in which surface sea water temperatures in the central and eastern tropical Pacific Ocean are warmer than average.
Its name means the Little Boy, or Christ Child in Spanish. El Niño was originally recognized by fishermen off the coast of South America in the 1600s with the appearance of unusually warm water in the Pacific Ocean around Christmas.
The entire natural climate cycle is officially known as El Niño – Southern Oscillation, called ENSO by scientists. The cycle swings between warmer and cooler seawater in a region along the equator in the tropical Pacific. La Niña is marked by cooler-than-average ocean water in the region.
How warm are water temperatures?
In the El Niño region along the equator west of South America, sea-surface temperatures have risen sharply recently. With near-record sea surface temperatures pushing westward in the El Niño region, it's a telltale sign of the beginning of an El Niño.
El Niño formation 'well underway'
The formation of the cyclical pattern is already "clearly well underway," according to Daniel Swain, a climate scientist with the University of California Agriculture and Natural Resources. The atmosphere and oceans are cooperating and appear to be consistent with model forecasts for "a significant El Niño to develop by mid-summer," Swain wrote in a recent update on his WeatherWest website.
NOAA's most recent forecast predicted El Niño likely would form in June or July. The agency's next update on the climate pattern is expected on June 11.
The formation of El Niño is forecast to lead to a busier-than-normal hurricane season in the Pacific and possibly a slightly below-normal season in the Atlantic basin, according to seasonal forecast outlooks.