ACT News

Ski seasons under threat: CSIRO climate report

A CSIRO and Bureau of Meteorology climate change report has put a dark cloud over future ski seasons, predicting an upsurge in extreme weather and more bushfires.

The report also makes new predictions of temperature rises for Canberra, tipping dramatic drops in days of less than 2  degrees and a burst in the number of 35 to 40-degree days. 

The information is in the first update of the agencies' Natural Resource Management report since 2007, and builds on improved modelling to project how the climate for the city and the country is likely to differ by 2030 and 2090.

"We expect more hot days and hotter hot days and fewer cold days," said Kevin Hennessy, Commonwealth Scientific and Industrial Research Organisation's (CSIRO's) group leader for climate. "We're starting to see what we can expect in the future with greater frequency and intensity."

Australia's average temperatures have warmed 0.9 degrees since 1910, with rising greenhouse gases a contributing factor. More warming and other climate impacts are predicted for 2030 but the severity and extent of changes beyond then hinge on whether global carbon emissions are reduced.

The report is particularly bad news for Canberra ski enthusiasts, retailers and Snowy Mountains ski resorts, with predictions of fewer frosts.

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Frost-risk days (minimum temperatures less than 2 degrees) are projected to decrease across the Murray Basin prediction region Canberra is included in and could halve by late in the century, the report says.

From the current average of 91 days a year of less than 2 degrees, by 2090 the Canberra region can expect 68 days a year under a medium emissions outlook to just 43 under higher emissions.

In just 15 years the number of days a year of less than  2 degrees is expected to drop to 81. 

Mr Hennessy said he expected the decrease in snow over the past 60 years "to continue".

"The precipitation is likely to fall more as rain than as snow and secondly the snow that does lie on the ground melts faster," he said.

The report's rain and temperature predictions contain a call for emission reductions.

"Beyond 2030, the different types of emission scenarios really matter and global action to reduce emissions can have a big effect on the ultimate impacts," Mr Hennessy said.

"Annual average temperates in Canberra are likely to go up between 0.6 to 1.1 degrees by the year 2030, and as we move to the year 2090 the predictions depend on the emissions reduction scenario.

"Under intermediate emissions, it would be 1.3 to 2.4 degrees and for high emissions it would be an increase of 2.7 to 4.5 degrees," he said.

The report also has bad news for the region's farmers.

Rainfall is expected to decrease in the winter months and stay about the same in the warmer months, while summer rain might increase for much of the rest of the country, it said.

"The projection for Canberra is for warmer conditions with drying in winter and spring but not much change for summer and autumn."  

However, Mr Hennessy said despite the dry winters "we would see an increase in extreme rainfall and intensity".

However, rising temperatures are likely to cause more evaporation, reducing the benefits. Overall soil moisture and run-off levels are also likely to drop, affecting agriculture and water management, the report found.

It also contains ominous warnings of dangerous bushfire seasons.

"The warmer and drier conditions would lead to more intense fires, so there are challenges for the management of extreme weather events," Mr Hennessey said.

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