A 'super El Niño' could plunge the UK into a freezing and wet winter after baking the rest of the world, experts warn.
What is El Niño?
Every three to seven years, global temperatures are pushed by a naturally occurring weather system called El Niño that shifts ocean winds. An El Niño supercharged by climate change, which has already begun, is slated to be especially powerful and smash heat records. Extreme rainfall, powerful storms and drought across some areas of the globe are all possible.
El Niño was seen well before humans raised the planet's temperatures by burning fossil fuels. No two El Niño events are the same, but they happen when changing air pressure weakens trade winds, which blow warm oceanic water out west. Without this wind, more water kept warm by the sun pools in the central and eastern Pacific Ocean and releases stored-up heat.
'An El Niño is declared when sea surface temperatures in parts of the Pacific Ocean are at least 0.5°C above the long-term average,' Aimee Mook, a curator at the National Maritime Museum, told Metro. Mook says that this determines how 'super' an El Niño is, with Australia's Bureau of Meteorology expecting this year's to peak at 3.3°C. 'Climate models suggest it could be among the strongest seen in recent decades,' she added. 'When El Niño occurs in a world that is already warming because of climate change, its impacts can be more noticeable.'
How will El Niño affect the UK?
It's hard to say for sure, as the El Niño is only just gathering strength and the effects will play out in the winter and next year. Huge blobs of warm, moist air are now rising from the sea surface, which can form thunderstorms and raise precipitation levels. This could make the winter wetter or even snowier-than-average, dragging out the cold until as far as April, as some climate experts predict.
But Jim NR Dale, a meteorologist with the British Weather Services, says it's still too early to tell. 'I wouldn't bet on anything UK-orientated but wetter winters, particularly after this summer, appear more likely than not in our “new” climate zone,' he says. 'But all of that is set against ongoing climate change. Winner takes all, but a draw is entirely possible.'
Super El Niño will only 'side glance' the UK in terms of extreme weather, Dale adds, but the same can't be said elsewhere. As the oceans and atmosphere are cooked, it increases the availability of energy and moisture that fuel fierce weather.
Global impacts
In the US, the effects of El Niño are evenly split – the north sees little rain and scorching heatwaves, while the south gets drenched by winter storms. El Niño can create warm, dry conditions in Asia and the Indian subcontinent, drying out their rainy seasons and causing wildfires and crop-ravaging droughts. 'The knock-on effects are likely to be shortages and steep price rises in agricultural commodities such as cocoa, coffee and rice,' says Dale.
Australia and the wider Oceania typically see below-average rains and are bracing for wildfires. Aussie weather officials say that state capital cities have at least an 80% chance of an unusually warm and dry spring. But what will impact the entire world, adds Dale, are the 'migration issues due to people living in regions that cannot sustain life.'
