Global warming is expected to increase the incidence of “super El Ninos”, which can cause multibillion-dollar losses and thousands of deaths.

New research from the University of NSW and the Australian Research Council says that even under modest climate change scenarios, the devastating events would hit twice as often.

Super El Ninos, such as those in 1982 and 1997, feature sea surface temperatures that begin warming in the west of the Pacific basin and spread eastwards.

Normal El Ninos begin in the eastern Pacific and expand westwards.

The study finds weakening westward currents along the Equator cause the unusual conditions. As the currents slow and even reverse, heat spreads more easily into the eastern Pacific.

“These currents are well represented in a number of climate models,” lead author Agus Santoso of the University of NSW Climate Change Research Centre said.

“Using these models we confirmed, even under modest global warming scenarios, these unusual El Nino events doubled in frequency.”

The 1982 and 1997 events disrupted fisheries and agriculture, leading to the deaths of tens of thousands of people and losses of tens of billions of dollars.

“While more frequent eastward-propagating El Ninos will be a symptom of a warming planet, further research is under way to determine the impact of such events in a climate that is going to be significantly warmer than today,” co-author and CSIRO scientist Wenju Cai said.