The El Nino 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 that there was a 60% chance of El Nino 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 Nino, 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 happened in 2018-2019 and gave way to a particularly long episode of La Nina, 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 Nina, 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 Nino will most likely lead to a new peak in global warming and increase the chances of breaking temperature records," he warned.
At this stage, it is not possible to predict the intensity or duration of El Nino 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 Nino and warming caused by human-induced greenhouse gases" .
The effects of El Nino 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 Nino," warned the head of the OMM.
This "could provide respite from the Horn of Africa drought and other La Nina-related impacts, but could also trigger more extreme weather and climate events," he said. He underlined the need to set up early warning systems -one of WMO's priorities- to protect the populations most at risk.
No two El Ninos 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 of the next predicted episode.
The phenomenon occurs on average every two to seven years and usually lasts nine to 12 months.
It is generally associated with warming ocean surface temperatures in the central and eastern tropical Pacific Ocean.
El Nino generally causes increased precipitation in parts of southern South America, the southern United States, the Horn of Africa and Central Asia, while El Nino can cause severe droughts in Australia, Indonesia and parts of South Asia.
During the boreal summer - the hot season in the northern hemisphere and cold in the southern hemisphere - the warming of surface waters caused by El Nino can also fuel hurricanes in the central and eastern Pacific Ocean, while preventing the formation of hurricanes in the Atlantic basin, explained the WMO.
03/05/2023 19:17:18 - Geneva (AFP) © 2023 AFP
