The bad boy of global weather is on its way. El Niño can cause floods, droughts, fires and epidemics around the world, and the next one could be a humdinger.
Severe Flooding, Against a Background of Wind Turbines (Image: T. Larkum)
El Niño crashes on to the scene once every four years or so as hot water emerges in the Pacific and moves towards the Americas. This can bring drought to Australia and parts of Asia, while parts of the Americas experience heavy rain, flooding and outbreaks of waterborne diseases. Pacific Islands all the way from Tonga to Hawaii experience more frequent storms. And valuable fish stocks move all around the globe, following water of their preferred temperature.
Many experts are warning of a “super El Niño” this time round.
“We have this enormous heat in the subsurface that is propagating eastward and it’s just about to come to the surface,” says Axel Timmermann of the University of Hawaii in Honolulu. “I looked at the current situation and I thought, ‘oh my dear’.”
Similar forecasts were made last year, too, and proved wide of the mark. This time it’s different. For one thing, we are already in an El Niño year, which makes it easier for an extreme one to form.
“It’s much easier to build up from warm temperatures than from neutral temperatures,” says Timmermann.
Also, this year ocean temperatures seem to be coupled with atmospheric winds in a feedback loop that makes the El Niño stronger, says Wenju Cai at the CSIRO, Australia’s government research agency. US climate models, on average, are pointing to an El Niño comparable to the devastating 1997/98 event, says Timmermann.
Another thing likely to give this year’s El Niño an extra kick is the presence of the Southern Hemisphere Booster. A low-pressure system near Australia that boosts westerly winds across the Pacific, it helps unlock the heat fuelling El Niño, says Fei-Fei Jin of the University of Hawaii at Manoa.
“The chance of a large El Niño is quite large,” he says.
Timmermann says we should be preparing, clearing rivers of debris in flood-prone areas and storing water in drought-prone areas.
“There are lots of win-win things you can do,” he says.
He has already installed hurricane clips on his roof, as El Niño also increases the chances of hurricanes making landfall on Hawaii.
Source: New Scientist