Scientists have warned that the return of the El Nio climate phenomena later this year will lead global temperatures to surge “off the charts” and deliver extreme heatwaves.
Early estimates indicate that El Nio will return later in 2023, aggravating extreme weather around the planet and making it “extremely likely” that the earth will warm beyond 1.5 degrees Celsius. The warmest year on record, 2016, was led by a strong El Nio.
It is part of a natural oscillation in the Pacific caused by ocean temperatures and winds, which alternates between El Nio, its colder counterpart La Nia and neutral circumstances. The previous three years have seen a unique string of La Nia incidents.
This year is already forecast to be hotter than 2022, which global datasets rank as the fifth or sixth hottest year on record. But El Niño occurs during the northern hemisphere winter and its heating effect takes months to be felt, meaning 2024 is much more likely to set a new global temperature record.
Read also: German climate activists to stage new protests over Coalmine expansion
The greenhouse gases emitted by human activities have driven up the average global temperature by about 1.2C to date. This has already led to catastrophic impacts around the world, from searing heatwaves in the US and Europe to devastating floods in Pakistan and Nigeria, harming millions of people.
“It’s very likely that the next big El Niño could take us over 1.5C,” said Prof Adam Scaife, the head of the long-range prediction at the UK Met Office. “The probability of having the first year at 1.5C in the next five-year period is now about 50:50.”
“We know that under climate change, the impacts of El Niño events are going to get stronger, and you have to add that to the effects of climate change itself, which is growing all the time,” he said. “You put those two things together, and we are likely to see unprecedented heatwaves during the next El Niño.”
The fluctuating impacts of the El Niño-La Niña cycle could be seen in many regions of the world, Scaife said. “Science can now tell us when these things are coming months ahead. So we really do need to use it and be more prepared, from having readiness of emergency services right down to what crops to plant.”
Prof James Hansen, at Columbia University, in New York, and colleagues said recently: “We suggest that 2024 is likely to be off the chart as the warmest year on record. It is unlikely that the current La Niña will continue a fourth year. Even a little futz of an El Niño should be sufficient for record global temperature.” He said that declining air pollution in China, which blocks the sun, was also increasing heating.
While El Niño would supercharge extreme weather, the degree of exacerbation was under debate among scientists.
Climate modelling results issued in early January by Australia’s Bureau of Meteorology indicated the country could swing from three years of above-average rainfall to one of the hottest, driest El Niño periods on record, increasing the risk of severe heatwaves, droughts and fires. In December, the US National Oceanic and Atmospheric Administration rated the odds of an El Niño forming by August-October as 66%.
This story was adapted from The Guardian.
