Extreme weather events fuelled by unusually strong El Ninos, such as the 1983 heatwave that led to the Ash Wednesday bushfires in Australia, are likely to double in number as our planet warms.
An international team of scientists from organisations including the ARC Centre of Excellence for Climate System Science (CoECSS), the US National Oceanic and Atmospheric Administration and CSIRO, published their findings in the journal Nature Climate Change.
"We currently experience an unusually strong El Nio event every 20 years. Our research shows this will double to one event every 10 years," said co-author, Dr Agus Santoso of CoECSS.
"El Nino events are a multi-dimensional problem, and only now are we starting to understand better how they respond to global warming," said Dr Santoso. Extreme El Nio events develop differently from standard El Ninos, which first appear in the western Pacific. Extreme El Nino's occur when sea surface temperatures exceeding 28C develop in the normally cold and dry eastern equatorial Pacific Ocean. This different location for the origin of the temperature
increase causes massive changes in global rainfall patterns.
"The question of how global warming will change the frequency of extreme El Nio 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 Nio events extend to every continent across the globe.
The 1997-98 event alone caused $35 US billion in damage and claimed an estimated 23,000 human lives worldwide.
"During an extreme El Nio event countries in the western Pacific, such as Australia and Indonesia, experienced devastating droughts and wild fires, while catastrophic floods occurred in the eastern equatorial region of Ecuador and northern
|Contact: Alvin Stone|
University of New South Wales