A super-sized El Niño weather pattern in the Pacific Ocean is set to cause a devastating drought in the Amazon, fuelling the risks of huge wildfires in a region already feared to be approaching a climate tipping point. El Niño is a natural climate phenomenon that occurs when sea-surface temperatures in the tropical Pacific rise above normal, driven by shifts in trade winds. El Niño tends to push up global temperatures and unleash extreme weather around the world.
One of Earth’s most vital carbon sinks is faltering. Scientists monitoring the current El Niño’s development say it is set to be the most intense in modern history by a large margin. Already, ocean temperatures in the Pacific are well above what would be expected for a normal El Niño and are still rising, prompting warnings of extreme impacts.
Very strong El Niños like this tend to concentrate their heat close to the coast of South America, says Adam Scaife at the Met Office, the UK’s national weather service. That, in turn, leads to more intense impacts in the region, including drought in the Amazon, he says. The most up-to-date forecasts from the Met Office show a “terribly dangerous [rainfall] anomaly” developing over the Amazon by January, says Scaife.
Hotter air temperatures are also expected in the region due to El Niño. The Amazon rainforest plays a key role in removing carbon dioxide from the atmosphere and is a globally significant biodiversity hotspot. But severe drought can have dire consequences for wildlife and the planet.
An extreme Amazon drought during the 2015-16 El Niño event fuelled huge wildfires, destroying around 2.5 billion trees and plants, and emitted 495 million tonnes of CO2, according to research led by the University of Oxford. Scientists also warn that repeated and increasingly severe droughts mean the Amazon is approaching a climate tipping point, at which the rainforest ecosystem collapses and is replaced by savannah. Tim Li at the University of Hawaii thinks the Amazon is set to suffer the most extreme El Niño-induced drought on record.
The looming El Niño could be bad – but much worse is to come Rainfall over the Amazon during June, July and August was well below average, despite the El Niño phase still being in its infancy. In the Amazon you already see drought,” says Li. Assuming this year follows the pattern of previous large El Niños, that rainfall pattern will only intensify over the coming months, he says.
Extract — continue reading at the source.
