Credit: Bagus Kurniawan/NurPhoto via Getty
The waters off the coast of Peru are normally one of the most productive fisheries in the world, each year producing millions of tonnes of anchovies to be used for fertilizer and animal feed. But in late August, the government cancelled the anchovy season early: the El Niño event gaining strength in the tropical Pacific Ocean has increased ocean temperatures and sent full-grown anchovies in search of food to deeper, colder waters, ruining the catch.
That is just one example of how this year’s monster El Niño is causing disruptions globally. Forecasts for the months ahead suggest that the impacts will be felt in many locations normally associated with El Niño’s influence, says Deepti Singh, a climate scientist at Washington State University in Vancouver. That includes drought in areas around the equator, Central America and the western Pacific Ocean, as well as extreme rainfall in the horn of Africa, western United States and the Pacific coast of South America.
But this El Niño is forecast to reach unprecedented strength. That, combined with the influence of global warming, could mean that the effects of this event look different from the strong El Niños of the past. “You change the patterns and the weather reacts,” says Eran Vos, a climate scientist at Bar-Ilan University in Ramat Gan, Israel.
Flavours of El Niño
El Niños occur when sea-surface temperatures in the tropical Pacific Ocean become abnormally warm. This affects air temperatures in the atmosphere above the region, shaping wind and weather patterns across the globe.
Not all El Niños have the same influence on weather. El Niños caused by warm ocean temperatures in the central Pacific behave differently to ones formed in the eastern Pacific. And weather patterns during strong El Niño events are different from those caused by moderate ones. “El Niños come in flavours, like ice creams,” says Jérôme Vialard at the Research Institute for Development in Marseille, France.
This event is the first strong El Niño with an eastern Pacific flavour since the late 1990s, says Vos. That means that there’s not a lot of precedent for how it will influence weather when combined with almost three decades of global warming.
There are a few other aspects that make this year unique. The El Niño has strengthened earlier than it did during previous strong events, such as the ones that occured in 1997 and 2015. Some forecasts suggest that this El Niño could become the strongest one in centuries, combining with background global warming to raise average temperatures in 2027 to record levels.
Dry and wet
Researchers say that, so far, the emerging effects of this El Niño resemble those of previous strong events.
Drought conditions in Central America have slowed shipping traffic on the Panama Canal, which uses freshwater to fill its locks for each passing ship. Tens of thousands of smallholder farmers in Guatemala, Honduras and El Salvador have reported crop losses. In the Caribbean, an historic drought worsened by climate change has intensified further, leading to water-rationing in Puerto Rico and crop stress in Jamaica.
This hot, dry pattern extends around the equator. Indonesia has seen an above-average start to the wildfire season. Meanwhile, India has had a lower-than average monsoon rainfall, even as flooding has hit some of the country — an expected effect of El Niño. In parts of southern and East Africa, dry weather combined with high prices for fuel and fertilizer is threatening food security. A June report from the United Nations World Food Programme projected that tens of millions of people in these regions will experience acute food insecurity due to the El Niño.
Meanwhile, other parts of the planet tend to see too much rain during El Niño events. Heavy rain and snow in Chile and Peru have caused flooding, disrupted copper mining and closed the Incan citadel Machu Picchu to tourists. The Horn of Africa is predicted to see flooding similar to what occurred during the 2023 El Niño, which displaced millions of people.
