The El Niño weather phenomenon is likely to form this year and could push temperatures to new record highs, the UN warned on Wednesday.
The World Meteorological Organization (WMO) now estimates there was a 60% chance of El Niño developing by the end of July and an 80% chance by the end of September.
“This will change weather and climate conditions around the world,” explained the head of the WMO’s Regional Climate Prediction Services Division, Wilfran Moufouma Okia, at a press conference in Geneva.
El Niño, is a natural climatic phenomenon generally associated with an increase in temperatures, increased drought in some parts of the world and heavy rains in others.
It last occurred in 2018-2019 and gave way to a particularly long episode of La Niña, which causes the opposite effects and in particular a drop in temperatures.
Despite this moderating effect, the past eight years have been the warmest on record.
Without La Niña, the warming situation could have been even worse.
It “acted as a temporary brake on global temperature rise,” WMO chief Petteri Taalas said in a statement. “The development of El Niño will most likely lead to a new peak in global warming and increase the chances of breaking temperature records,” he warned.
More extreme
At this stage, it is not possible to predict the intensity or duration of El Niño that is looming. The latest one was considered weak, but the one before, between 2014 and 2016, was powerful and had disastrous consequences. The WMO pointed out that 2016 was “the warmest year on record due to the ‘double effect’ of a very strong El Niño and warming caused by greenhouse gases linked to human activity” .
The effects of El Niño on temperatures are generally felt the year following the emergence of the meteorological phenomenon, its impact will probably be felt more in 2024, underlines the WMO.
“We expect a sharp rise in global temperatures over the next two years,” Okia said.
“The world must prepare for the development of El Niño,” warned the head of the WMO.
This “could bring relief from the Horn of Africa drought and other La Niña-related impacts, but could also trigger more extreme weather and climate events,” he said. He stressed the need to set up early warning systems — one of WMO’s priorities — to protect the populations most at risk.
No two El Niños are the same and their effects depend in part on the time of year, the WMO said, adding that it and national meteorological services would closely monitor developments in the next predicted episode.
The phenomenon occurs on average every two to seven years and generally lasts from 9 to 12 months.
It is generally associated with warming ocean surface temperatures in the central and eastern tropical Pacific Ocean.
El Niño generally causes increased precipitation in parts of southern South America, the southern United States, the Horn of Africa and Central Asia, while El Niño can cause severe droughts in Australia, Indonesia and parts of South Asia.
During the boreal summer — the hot season in the northern hemisphere and the cold season in the southern hemisphere — warming surface waters caused by El Niño can also fuel hurricanes in the central and eastern Pacific Ocean, while preventing the formation of hurricanes in the Atlantic basin, explained the WMO.