‘Exceptional event’: World braces for ‘supersized’ El Niño

Ireland can expect an unusually mild and wet autumn as a “supersized” El Niño develops, disrupting weather patterns worldwide. The World Meteorological Organisation (WMO) described the El Niño, a climate phenomenon that has been building since early summer, as an “exceptional event”. It said there was unprecedented consensus among national meteorological agencies about its strength and the duration of its impacts. They now say it will last until February 2027, driving up temperatures, disrupting rainfall and fuelling extreme weather events well into next year. Temperatures will be above normal across all landmasses, with variations from slight to severe in different regions. READ MORERainfall forecasts are much more varied, with drier-than-normal conditions and drought expected in some regions and significantly wetter weather and floods in others. The disruption is additional to that being caused by climate change, and comes as many parts of Europe, including Ireland, have yet to recover from the summer heatwaves and prolonged drought. El Niño is a natural climate phenomenon that occurs every two to seven years, driven by a build-up of heat in the waters of the equatorial eastern Pacific Ocean.Sea surface temperatures were almost 3 degrees above normal in the region last month, but subsurface temperatures were more than 8 degrees above average in some places. The extra heat is dispersed widely by air and sea currents, and it upsets normal climate patterns, particularly in areas accustomed to large seasonal events such as monsoon season, hurricane season or dry season. Impacts in Europe over the next three months are predicted to vary between northern and southern countries, with a particularly high probability of above-normal temperatures in the south, which will also be much wetter than normal. Northern Europe is expected to be slightly warmer than normal and also drier, but Ireland does not fall neatly into either region. “How El Niño affects Ireland is that it affects the drivers that affect us,” said Paul Moore, climatologist with Met Éireann. Those interactions can begin as remotely as the Indian Ocean, with El Niño causing a positive “dipole” that pulls warm water away from Indonesia and towards the Atlantic. That, in turn, feeds the waters that travel from the southern United States towards Ireland, the extra warmth bringing warmer, wetter conditions. “We would normally expect to see a cooler-than-normal late winter, from January on, but because this is an unprecedented El Niño, we don’t have the same certainty. “It may lead to continued milder, wetter conditions.” After the summer drought, many parts of Ireland would welcome consistent rainfall in the coming months, but persistent rain would prompt fears of a repeat of last winter’s flooding in the east and southeast of the country. Almost every other part of the world can expect disruption, with the WMO warning: “El Niño is firmly established and will intensify into a very strong event in the coming months, with big impacts on rainfall and temperature patterns and associated risks of floods, drought and extreme heat.” WMO secretary general Celeste Saulo said efforts were under way to get as much accurate information as possible and provide early warnings to the most vulnerable regions. “Never before in the 50-year history of the World Meteorological Organisation have we launched such a major mobilisation,” she said. “We have no time to lose.” United Nations secretary general António Guterres said the combined effects of El Niño and climate change were placing the planet in an unprecedented “danger zone”. “El Niño is being supersized before our eyes. The science leaves no room for doubt: the planet is in uncharted waters,” he said.