Australia records hottest decade ever
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Australia has sweltered through its hottest decade on record, officials said yesterday, linking a rise in heatwaves, drought, dust storms and extreme wildfires with global warming.
The Bureau of Meteorology also said 2009 was the second warmest year since detailed records began in 1910, with an annual mean temperature almost one degree Celsius (1.8 degrees Fahrenheit) above average.
Climatologist Dean Collins said the average for the decade, about 22.3 C, was 0.48 C above Australia's 1961-1990 benchmark average and indicated man-made global warming.
"For the past six decades, each decade has been warmer than the preceding one," Collins said.
"To get six, seven decades in a row that are warmer than the previous one - it doesn't happen by chance. It's reflecting what's happening at the global level."
Collins said while the higher temperatures were partly caused by an El Nino event in the Pacific - a weather effect associated with drier conditions - they had been superimposed on human-induced global warming.
Australia experienced three record-breaking heatwaves around the country in 2009, a highly unusual event which Collins said was consistent with global warming.
"Global warming increases the chance of getting heat waves like that but we can't categorically say it wouldn't have happened without global warming," he said.
"All we can really say is that global warming has increased the chance of getting those kinds of events."
The bureau expects more of the same in 2010, with a bias towards warm weather in the first three months of the year, Collins said.
Australia began 2009 with uncomfortably hot temperatures in the country's south with extreme heatwaves in Victoria and the island of Tasmania.
The bureau said these conditions contributed to the so-called "Black Saturday" bushfires in which 173 people perished as firestorms levelled entire villages, destroying more than 2,000 homes.
An unusual winter heatwave hit large parts of inland Australia mid-year, resulting in the country's warmest August on record, while another hot spell in November broke records in South Australia and New South Wales.
"Based on the analysis of daily (maximum and minimum) temperature data above and below set thresholds, there are clear upward trends in the number of hot events and downward trends in the number of cold events (over the period 1960 to date), consistent with the background of global warming," the bureau said.
According to the World Meteorological Organization, 2009 was the fifth warmest year for the planet on record.
