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| The Climate Council says September's mid-latitude cyclone was influenced by climate change. (Supplied: Bureau of Meteorology) |
Storms that knocked out electricity infrastructure in
South Australia and brought coastal flooding to New South Wales were
influenced by climate change and more could be expected in coming years,
the Climate Council says.
A
report released by the council said climate change was fuelling more
intense and damaging storms in Australia and would have "powerful
consequences" for critical infrastructure.
What was described by the Bureau of Meteorology as a mid-latitude cyclone hit SA during September and created tornadoes that knocked over more than 20 transmission towers and resulted in a state-wide blackout.BOM also released a report today confirming at least seven tornadoes touched down on September 28, an outbreak caused by multiple supercell thunderstorms.
Winds of up to 260 kilometres per hour were recorded with sheds destroyed and a caravan overturned in the state's Mid North.
One tornado lasted for 25 minutes and travelled about 23 kilometres, while another lasted 20 minutes and travelled 30km.
Separately, an intense low pressure system that hit NSW in June resulted in the evacuation of parts of Sydney and tens of millions of dollars in damages.
The NSW storm surge of 17.7 metres was the highest on record, the council said, and was exacerbated by rising sea levels "as a result of climate change".
The Climate Council's Professor Will Steffen said the atmosphere was "packing more energy and carrying more moisture than it did in the 1950s".
"Our infrastructure is built for last century, not for a changed climate and a number of our major cities and towns are vulnerable," he said.
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| Beachside homes in Sydney were damaged by June's storm event. (Fairfax Media: Peter Rae) |
The report said extreme rainfall events were projected to increase in intensity across the continent, with the exception of south-west Western Australia where reduced rainfall was projected.
The annual frequency of severe thunderstorm days was expected to increase 14 per cent in Brisbane, 22 per cent in Melbourne, and 30 per cent in Sydney by 2100.
It said tropical cyclones were predicted to become less frequent but more intense, with stronger winds, higher rainfall and more severe storm surges.
The council warned that infrastructure and essential services needed to be designed for increasingly intense and severe weather caused by climate change.
It said seven storms since 2010 in Australia have resulted in insured losses of more than $500 million, with five them causing more than $1 billion in insured losses.
BOM meteorologist Matthew Bass said it was difficult to attribute single events, such as the storms in SA or NSW, to climate change.
"Those sorts of storms are not unheard of, but they're very, very rare," he said."For example, the surface air pressure in Adelaide was the lowest on record, but that's our historical record that goes back 100 years or so. It's probably likely that we have had similar lows, with recurring intervals of 150 years or so, that we just don't know about."
On the subject of extreme rainfall events, however, when the atmosphere is hotter due to climate change and holds more moisture as a result, it was easier to point to climate change.
"And when you're talking about a bushfire [for example], you can measure the excess heat in the atmosphere, and the excess dryness due to the heat," Mr Bass said.
Australia's worst storms of the past six years
| Date | Location | Event | Insured losses |
|---|---|---|---|
| March 2010 | Melbourne, Vic | Large hailstones hit the city of Melbourne, damaging schools, businesses and homes. | $1.04 billion |
| March 2010 | Perth, WA | Winds of up to 120 kilometres per hour damage houses, schools and vehicles. | $1.05 billion |
| January 2011 | Brisbane, Lockyear Valley, Ispwich, Qld | Extreme rainfall causes major flooding that inundates housing and destroys roads. Some 25 people are killed. | $2.4 billion |
| February 2011 | Cardwell, Tully, Mission Beach, Innisfail, North Qld | Category 5 tropical cyclone Yasi hits, resulting in one death. Homes are destroyed and agriculture and mining infrastructure are damaged. | $1.4 billion |
| December 2011 | North and eastern suburbs, Melbourne, Vic | Thunderstorm brings torrential rain, hailstones and tornadoes. | $729 million |
| November 2014 | Brisbane, Qld | Strong hail storm hits the city along with winds of up to 140kph. | $1.39 billion |
| April 2015 | Hunter Valley and NSW coast | More than 400mm of rain falls in 48 hours. Wind gusts of 135 kph hit, three deaths are caused and 370,000 properties experience a power outage. | $950 million |
| May 2015 | South-east Qld | Some 183mm of rain falls in just 24 hours in Brisbane, its wettest day in May for 175 years. Houses are damaged and five deaths are caused. | $349 million |
| June 2016 | East coast of NSW, southern Qld and Sydney | A record-high storm surge of 17.7 metres results in coastal erosion and the deaths of five people. | $235 million |
| September 2016 | SA | Extreme rainfall and at least seven tornadoes result in a state-wide blackout affecting nearly 1.7 million people that lasts up to three days in some areas. | Undetermined |
Large hail events more frequent in eastern states
A spring thunderstorm slammed parts of Adelaide and SA with golf ball-sized hailstones late last week.
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| Hail stones collected from Stepney in Adelaide's east on Friday. (ABC News: Simon Christie) |
Thunderstorms later moved into Victoria's far north-west where strong winds and a small tornado caused extensive damage.
Mr Bass said such storms were common in the eastern states but less common in SA."We've found four instances in the last six years, of what we call large hail in the Riverland, which is greater than two centimetres," he said.
"If that goes right through your cropping area, or the middle of Adelaide as well, that's going to be pretty significant.
"If you're in Sydney or Brisbane, you'd be pretty used to seeing a couple of these every year, but in Adelaide, it's more like once every five years or 10."The Climate Council said Australia needed to do more to reduce its carbon emissions and help "stabilise" the world's climate.
It said Australia's "very weak target" of a 26 to 28 per cent reduction in 2005 emission levels by 2030 was well behind the targets of other OECD countries and Australia was on track to miss its target anyway.
Links
- Can You Spot The Reason South Australia Doesn’t Have Power?
- South Australia: Failing To Learn The Correct Lessons Will Mean A Failure To Deliver Secure, Affordable Energy In Our Future
- Lessons From South Australia’s Blackout: We Need To Make Infrastructure More Resilient To Climate Change
- South Australian Storm A Preview Of Climate Change - Lethal Heating
- CO2 emissions fall raises climate change hopes
- 'Worst wind I've ever seen': 'Mini tornado' wreaks havoc in Mildura
- Golf ball-sized hail pelts Adelaide in sudden downpour
- Crops devastated by hail, winds in SA Riverland
- Power 'gradually' returning after SA plunged into darkness
- Hundreds evacuate as wild weather hits NSW
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