After May’s soaring temperatures, experts warn this heatwave could be just the beginning. Scientists tell Helen Coffey why they fear one of the most powerful weather events ever seen could be soon heading our way
There’s definitely something coming. We’re very confident about that, and it looks like it will be a big event.”
Adam Scaife, head of long-range prediction at the UK Met Office, recently gave this somewhat ominous proclamation. He was talking about the potential approaching El Nino – possibly so strong it may be classified as a “Super El Nino” – and warned it could “even be of record strength”.
The El Nino effect is a natural, cyclical climate pattern in the Pacific Ocean, characterised by the warming of surface ocean temperatures in the central and eastern equatorial Pacific.
Under normal conditions, trade winds blow westward along the equator, pushing warm water from South America towards Asia; cold water rises from below to replace this warmer water in a process known as upwelling. But El Nino throws all that into disarray. Trade winds aren’t as strong, and so the warm waters head east towards the Americas instead, forcing the Pacific jet stream south of its neutral position.
Upwelling weakens or stops altogether; without the nutrients being transported from the depths to the shallows of the ocean, there are fewer phytoplankton off the coast, which in turn impacts fish that eat phytoplankton, which in turn impacts everything that eats fish. Entire ecosystems are disrupted by the change.