UN experts said Wednesday that the La Niña weather phenomenon, which exacerbated droughts and floods, is finally over, but that the next, El Niño, could bring other problems.
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Thanks to La Niña, a weather phenomenon that tends to lower the temperature of the oceans and has been raging since 2020, the warming has been moderated slightly in the past year.
The United Nations World Meteorological Organization (WMO) said in its quarterly update that 2021 and 2022 were warmer than any year before 2015.
“The cooling effect of La Niña has temporarily curbed the rise in global temperatures, even though the past eight years have been the hottest on record,” said WMO Secretary-General Petteri Taalas.
He warned that the now adverse El Niño could return this summer and “risk fueling a new rise in global temperatures”.
La Niña is a large-scale cooling of surface temperatures in the central and eastern tropical Pacific Ocean.
They occur every two to seven years and alternate with El Niño and neutral conditions in between.
There is a 90% chance that conditions will be neutral between March and May, and it drops to 80% under April-June and 60% under May-July.
The chances of an El Niño developing are estimated at 15% in April-June, 35% in May-July and 55% in June-August.
“We need another two or three months to get a more reliable idea of what’s coming next,” warns Alvaro Silva, advisor at WMO.
He explained to AFP that tracking the fluctuation between the two phases helps countries prepare for their potential impacts, such as floods, droughts or extreme heat.
“With El Niño, there is an increased possibility of seeing the hottest year on record,” he added.
The World Meteorological Organization (WMO) warns that despite the end of La Niña, some of its effects on precipitation may persist due to its long duration.
While El Niño and La Niña are natural phenomena, they occur “in the context of human-induced climate change, which is raising global temperatures, affecting seasonal precipitation patterns, and making our climate more extreme,” emphasized the World Meteorological Organization (WMO).