El Niño could make 2015 hottest year on record

El Niño

Scientists predict the occurrence of an El Niño event later this year. Creative Commons: William Warby, 2013

The odds that 2015 will set a record for the warmest year since records begun are rising, as scientists predict an El Niño event will occur later this year.

In a new study, published in the Proceedings of National Academy of Sciences, found a 76% likelihood that such an event would occur before the end of 2014 – building on research put forward in 2013 that first proposed a new long-range El Niño prediction method.

El Niño refers to a recurring weather pattern that develops off the west coast of South America, causing warm temperatures and changes in climate.

Not only is such an event expected to mean 2015 will be the warmest year since records begun in the late 19th century, but it could also mean potentially disastrous weather next year.

El Niño can spark droughts in Australia and increased rain and floods in parts of the US and South America.

Last month scientists also warned of the link between climate change and strong El Niños. They found that while overall number of El Niños is unlikely to increase, particularly strong “super” El Niños are likely to occur twice as frequently in a warming world.

The new study, by an international group of researchers, takes a starkly different approach to El Niño forecasting compared to conventional techniques.

While the forecast models in use today tend to rely on observations of the ocean conditions and trade winds that generally blow from east to west across the tropical Pacific, the new method relies on an index that compares surface air temperatures in the area where El Niño events typically occur with temperatures across the rest of the Pacific.

The researchers found that a strong link between air temperatures across the Pacific and air temperatures in region where El Niño forms appears about one calendar year before an actual El Niño event.

Taking advantage of this observation, the scientists devised a forecasting index based on the strength of the links between temperatures in and around the El Niño region. This index, the study said, points to a high likelihood of an upcoming El Niño late in 2014.

“Our approach uses another route,” said study coauthor Armin Bunde, a scientist at the Institute for Theoretical Physics in Giessen, Germany, in an email conversation. “We do not consider the water temperature in a specific area of the Pacific Ocean, but the atmospheric temperatures in all areas of the Pacific.”

While the study claims to be more definitive than other forecasts, projections derived from ocean- and statistically-based models from the National Weather Service and the International Research Institute for Climate and Society (IRI) at Columbia University already show increasing odds, to the tune of twice the average risk, of an El Niño starting in the late summer or early fall as well.

Read more: Climate Central >>

Comments are closed.