‘Human-induced climate change’ to blame for Australia’s hottest year on record: scientists
Australia experienced its hottest year on record in 2013, the Bureau of Meteorology said Friday, enduring the longest heatwave ever recorded Down Under as well as destructive bushfires.
“2013 was Australia’s warmest year since records began in 1910,” the bureau said in its annual climate statement, released as inland areas of the country suffer scorching heatwave conditions.
“Mean temperatures across Australia have generally been well above average since September 2012. Long periods of warmer-than-average days have been common, with a distinct lack of cold weather.”
The bureau said that Australia’s 2012-2013 summer was the warmest on record, and included a prolonged national heatwave which ended on January 19, 2013 — the first day since 31 December, 2012 that it did not reach 45 degrees Celsius (113 F) somewhere in the nation.
Spring was also the warmest on record and winter the third warmest, meaning that overall, the annual national mean temperature was 1.20 degrees Celsius above average.
The bureau pointed to destructive fires, in the island state of Tasmania in early 2013, which were followed by a record warm and dry winter across the country.
Spring appeared to arrive early and culminated in “the most destructive fires in the Sydney region since at least 1968″.
The weather authority, which last year introduced new colours on its temperature scale to cater for more extreme highs, said the Australian warming was very similar to that seen on the global scale.
“And the past year emphasises that the warming trend continues,” it said.
This year is also starting warmly, with records already under threat in some Outback towns. In Moomba in northern South Australia, the temperature topped 48 degrees Celsius on Thursday. The highest temperature ever recorded in Australia was 50.7 Celsius in Oodnadatta in 1960.
Sarah Perkins, a climate system science researcher at the University of New South Wales in Sydney, said the report confirmed that the impacts of global warming were starting to be felt.
“While records are occasionally broken here and there, the amount of temperature records broken in the last year is extraordinary,” she said.
“Studies have already shown that the risk of summers like 2013 occurring have increased by up to five-fold, because of human induced climate change.”
Professor Roger Jones, a lead author on the Intergovernmental Panel on Climate Change’s Working Group II Fifth Assessment Report to be released later this year, said the findings should concern all Australians.
“While the increases in average temperatures may seem to be benign — heat waves are increasing faster than those averages,” said Jones, a research fellow at Victoria University in Melbourne.
“Why heat waves are longer and hotter than anticipated is not yet clear, but they are contributing to greater fire danger and heat stress than projected by climate impact studies, affecting animals, plants and humans.”
University of Melbourne climate scientist David Karoly said the record high average temperature was remarkable because it did not occur in an “El Nino” year, when conditions in Australia are usually drier and warmer.
He said that in climate modelling experiments conducted so far it was not possible to reach such a temperature record due to natural climate variations alone.
“Hence, this record could not occur due to natural variability alone and is only possible due to the combination of greenhouse climate change and natural variability on Australian average temperature,” he said.
Ian Lowe, emeritus professor of science, technology and society at Queensland’s Griffith University and president of the Australian Conservation Foundation, said the report confirmed expectations.
“2013 was the hottest year on record for Australia, showing that there is no rational basis for the claim that warming has slowed in recent years,” he said.