Thanks to La Nina, a weather phenomenon that tends to lower the temperature of the oceans and has been raging since 2020, the warming has been mitigated a little in the last year.
Still, the years 2021 and 2022 were warmer than any year before 2015, the UN’s World Meteorological Organization (WMO) said in its quarterly update.
“The cooling impact of La Nina has put a temporary brake on global temperature rise, even though the past eight years have been the hottest on record,” said WMO Secretary-General Petteri Taalas.
Now its opposite El Nino might be back this summer and “risks fueling a new spike in global temperatures”, he warned.
La Nina is a large-scale cooling of surface temperatures in the central and eastern equatorial Pacific Ocean.
It occurs every two to seven years and alternates with El Nino and neutral conditions in between.
Uncertain forecasts
There is a 90% chance of conditions being neutral between March and May, dropping to 80% on the April-June window and 60% in May-July.
The chances of El Nino developing are estimated at 15% in April-June, 35% in May-July and 55% in June-August.
“We need two or three more months to have a more reliable idea of what will follow,” warns Alvaro Silva, consultant at WMO.
Tracking the oscillation between the two phases helps countries prepare for their potential impacts, such as floods, droughts or extreme heat, he told AFP.
“With El Nino, there is an increased likelihood of seeing the hottest year on record,” he added.
The WMO warns that despite La Nina ending, some of its effects on rainfall may persist due to its long duration.
While El Nino and La Nina are natural phenomena, they occur “in the context of human-induced climate change, which is raising global temperatures, affecting seasonal rainfall patterns and making our climate more extreme”, a underlined the WMO.
