Get Used to Heat Waves: Extreme El Nino Events to Double

Some of the worst El Niños, the infamous climate patterns that shake up weather around the world, could double in frequency in upcoming decades due to global warming, says a new study out Sunday in the journal Nature Climate Change.

During an El Niño, water temperatures in the central and eastern equatorial Pacific Ocean tend to be warmer-than-average for an extended period of time – typically at least three to five months.  This warm water brings about significant changes in global weather patterns.

The most powerful El Niños – such as the ones that developed in 1982-83 and 1997-98 – are forecast to occur once every 10 years throughout the rest of this century, according to study lead author Wenju Cai of the Commonwealth Scientific and Industrial Research Organisation, Australia's national science agency.  Over the past 100 years or so, however these "extreme" El Niños occurred only once every 20 years, he said.

This means that the extreme weather events fueled by El Niños – such as droughts and wildfires in Australia, floods in South America and powerful rainstorms along the U.S. West Coast – will occur more often.

"The question of how global warming will change the frequency of extreme El Niño events has challenged scientists for more than 20 years," said co-author Dr Mike McPhaden of US National Oceanic and Atmospheric Administration.

"This research is the first comprehensive examination of the issue to produce robust and convincing results," said Dr McPhaden.

The impacts of extreme El Niño events extend to every continent across the globe.

Climate Change Could Spawn More Frequent El Ninos