New Research Claims Climate Change Will Intensify El Niño Events in Australia

11/4/2013 1:59:10 PM

Australia may face more intense and frequent bouts of extreme weather in the future as global warming "energizes" the El Niño-Southern Oscillation (ENSO), the dominant climate system over the Pacific Ocean, according to an Australian-led team of researchers.

The research, led by Shayne McGregor at the University of New South Wales' Climate Change Research Centre, found that the ENSO phenomena were more active and intense during the 1979-2009 period that at any time in the past 600 years.

An El Niño occurs when the central and eastern Pacific waters are relatively warm, weakening easterly winds. A reduction in clouds typically results in droughts and heat waves for eastern Australia in particular.

In late July 2013, a low pressure system off Australia's southeast coast and moist onshore winds combined to create unsettled weather across central Australia - and a striking image of a broad cloud band across the stark winter landscape. Photo by NASA Goddard Photo and Video

La Niña years see the patterns reverse, with sea surface temperatures to Australia's north relatively warm and floods more common. "In Australia, we don't want El Niño to become more variable," said Matthew England, a co-author of the report.

England said the research found a minimum of ENSO variance during the Little Ice Age from 1550 to 1880.

The opposite looks likely to be true, however, as humans pump more greenhouse gases into the atmosphere, driving temperatures higher.

Australia's extraordinary run of above-average temperatures continued in October despite ENSO being in "neutral" mode, neither El Niño nor La Niña.

Sydney, for instance, recorded its second-hottest October on record and equaled the highest number of days of 32 degrees Celsius or higher at five.

Nationally, this month will probably be among the 10 warmest Octobers over the past century, the Climate Change Research Centre said. That's enough to make both the past 12 months and the year-to-date periods the hottest on record for Australia (Peter Hannam, Sydney Morning Herald, Oct. 31).

Reprinted from ClimateWire with permission from Environment & Energy Publishing, LLC. 202-628-6500.

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