Climate report: Hot days may double in Australia by 2090

Dried-up riverbed in Alice Springs Image copyright Getty Images
Image caption Unseasonal heat has dried up riverbeds in Alice Springs

The annual number of very hot days in inland Australia could more than double in 75 years, according to a forecast of the effects of climate change by Australian science agency CSIRO.

Towns such as Alice Springs could average more than 190 days per year where the temperature crosses 35C, the CSIRO's Kevin Hennessy told the BBC.

The town now records such temperatures on an average of 94 days annually.

Australia is often accused of ignoring the threat from climate change.

The country is one of the world's worst per capita greenhouse gas polluters.

Non-governmental organisations say the government lags behind other industrial countries in tackling greenhouse gas emissions. The emissions are blamed for rising global temperatures and climate change.

'Further warming'

The report, produced by the CSIRO - or Commonwealth Scientific and Industrial Research Organisation - and Australia's Bureau of Meteorology, is said to give the most detailed prediction yet of how the country's climate will change over the 21st Century.

Image copyright AP
Image caption Storms are likely to become more intense, according to the report

Mr Hennessy, a CSIRO principal research scientist, says Australia's weather and environment will be noticeably affected by climate change over the next 15 to 30 years. The report predicts that:

  • The hot, dry weather that contributes to bushfires will become more frequent and more intense
  • Floods are likely to become more common, while tropical cyclones will become less frequent but more violent
  • Sea-levels will rise, while changes in the temperature and composition of sea-water will harm marine wildlife and their habitat, such as coral reefs

"We expect further warming, with more extremely hot days and fewer extremely cold days," Mr Hennessy told the BBC. Over the next 75 years, he said, average temperatures in inland Australia could rise by up to 5.3C if global warming continued unchecked.

The inland warming is higher than the global average that has been anticipated by 2090 under the so-called worst-case scenario, where greenhouse gas emissions remain high.

For example, Mr Hennessy said, the town of Alice Springs could average up to twice as many very hot days per year by 2090.

The temperature in Alice Springs crosses 35C on an average of 94 days per year at the moment. By 2030, researchers estimate that the number of such days could be between 104 and 122 every year.

By 2090, under the worst-case scenario, the number of days where the mercury crosses 35C could be between 145 and 193. "So, it's over a third of the year over 35C," Mr Hennessy said.

Image copyright AFP
Image caption Australia is going to get more of the weather that contributes to bushfires, scientists warn

Were effective action to be taken against climate change by 2090, the research suggests Alice Springs would only record such temperatures on 115 to 152 days per year.

The report has based its projections on up to 40 global climate models, and is aimed at the natural resource management sector.

Australia's average temperature has warmed by 0.9C since 1910 - a rise blamed largely on greenhouse gas emissions. 2013 was Australia's hottest year on record. Last year was the third-warmest.

Conservationists have urged the government to act on the dangers.

"Unless greenhouse pollution is slashed, Australia's climate will change significantly," Victoria McKenzie-McHarg, Climate Change Program Manager for the Australian Conservation Foundation said.

"We can expect Sydney's climate to become more like Brisbane's, Melbourne's more like Dubbo's, and Perth's more like Geraldton's."

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