The El Niño weather phenomenon, usually associated with rising global temperatures, has officially begun and is expected to “gradually strengthen” in the coming months, raising fears of further global warming and more extreme weather events.
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According to the US Agency for Oceanic and Atmospheric Observation (NOAA), which announced Thursday the official arrival of El Niño, the latter “could lead to new temperature records” in certain regions.
Moreover, “depending on its strength, El Niño can have a range of impacts, such as increasing the risk of heavy rains and droughts in some places around the world,” said Michelle L’Heureux, climatologist at the NOAA, noting that “climate change may exacerbate or mitigate some of its effects.”
El Niño is a natural climate phenomenon characterized by warmer than normal surface temperatures in the equatorial Pacific Ocean, but it has consequences for the entire planet. It occurs approximately every two to seven years.
The last El Niño period dates back to 2018-2019 and gave way to a particularly long episode of almost three years of La Niña, which causes the opposite effects and in particular a drop in temperatures.
But despite this moderating effect, the past eight years have already been the hottest on record.
In early May, the World Meteorological Organization (WMO) warned that the period 2023-2027 would almost certainly be the hottest ever recorded on Earth, under the combined effect of El Niño and global warming caused by gas emissions. Greenhouse effect.
The WMO estimates a 66% chance that the global mean annual surface temperature will exceed pre-industrial levels by 1.5°C for at least one of the next five years. This was one of the limits not to be exceeded set by the Paris Agreement of 2015.
At this stage, it is not yet possible to predict the intensity or duration of the current El Niño. The latest one was considered weak, but the one before, between 2014 and 2016, was powerful and had disastrous consequences. In general, the effects of El Niño on temperatures are felt the year after it emerges.
Mr. Petteri Taalas, Secretary-General of WMO, however, has already sounded the alarm bell, insisting on the need to be prepared because “the repercussions on health, food security, water management and the environment will be considerable”.
Australia this week warned that El Niño would bring hotter, drier days to the bushfire-prone country, while Japan said a developing El Niño was partly to blame for its spring on hottest ever recorded.
Scientists fear that this summer and the next will be particularly difficult in certain regions, especially the most disadvantaged.
“The poor are already pushed to the brink by droughts, floods and storms caused by the use of fossil fuels, and they will now have to deal with the supercharged temperatures of the El Niño effect,” Mariana Paoli stressed on Thursday. , of the humanitarian organization Christian Aid.
On the United States, the effects of El Niño should be more contrasted: its influence should be weak during the summer, but more pronounced from the end of the fall and until the spring, indicates the NOAA.
In winter, this would result in wetter than average conditions in parts of the country from southern California to the Gulf Coast, but drier conditions in the Pacific Northwest and the Ohio Valley. It also increases the chances of higher than normal temperatures in northern parts of the country.
South America, the Horn of Africa and Central Asia could also be affected by increased rainfall, while El Niño could cause severe droughts in Australia, Indonesia and parts of Asia from South.
In contrast, El Niño tends to moderate hurricane activity in the Atlantic, but favor it in the central and eastern Pacific.