Study: Global Warming Has Increased Australia’s Chances Of Extreme Summers Five-Fold

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Researchers at the University of Melbourne have concluded that Australia is much more likely to see extremely hot summers thanks to human-driven global warming. This finding is based on a raft of climate measurements, plus over 90 climate model simulations.

The context for the study is the record-smashing “Angry Summer” Australia just endured, which brought heat waves, brush fires, and both the hottest month and the hottest day the country has ever seen. According to the paper, by Sophie Lewis and David Karoly, the odds of such summers occurring have increased five fold between now and 2020 — and half the blame can be laid at the door of greenhouse gas emissions.

Climate always involves lots of natural variability, and Australia is no exception. The El Niño, a band of unusually warm water that cyclically develops across the Pacific Ocean, has historically been associated with unusually hot Australian summers. But the Pacific Ocean was recently almost in La Niña conditions — the opposite, colder extreme of the oscillation. That was the initial clue for Lewis and Karoly that connected the “Angry Summer” to human activity. As The Guardian reports:

“We cannot categorically ascribe the cause of a particular climate event to anthropogenic climate change; however, the roles of various factors contributing to the change in odds of an event occurring can be identified,” the two scientists write.

They examined the historical record of more than 150 years of observation, and found, repeatedly, that extreme summers tended to occur in step with El Niño years: in fact were three times more likely to happen in an El Niño year than a La Niña season.

Clearly, something else was at work in the Australian summer of 2013. Natural climatic variations were not likely to have caused the bush fires and the floods. It was possible to say, with more than 90 percent confidence, that human influences on the Australian atmosphere had dramatically increased the odds of extreme temperatures.

The key thing to understand when it comes to extreme weather is that the range of possible scenarios natural climate variations can produce exist along a bell curve. When human-driven global warming raises average temperatures, it shifts the bell curve so that more of the distribution lies in the extremes, increasing the odds of punishing heat, wildfires, floods, and all the rest in any given season.

Unfortunately, Australia is helping dig its own grave in some respects here. The country’s plans to double down on coal production and exports was noted by Greenpeace as one of 14 “carbon bombs” threatening the global climate. And all by themselves, the coal reserves Australia is considering exploiting could take up 75 percent of what the world can still burn without pushing global warming above two degrees Celsius. To top it off, Australia’s conservative opposition has vowed to undo the country’s embryonic carbon tax if it wins elections this September.

On the plus side, the price of Australian wind power is already outperforming that of fossil fuels — even in the absence of government assistance — with solar coming up rapidly behind it. And studies suggest that providing all of Australia’s electricity needs with renewables by 2030 is a goal that lies well within the realm of the realistically achievable.

14 Responses to Study: Global Warming Has Increased Australia’s Chances Of Extreme Summers Five-Fold

  1. Superman1 says:

    “Australia is helping dig its own grave in some respects”. In some respects? They are the world’s leading exporter of coal (, and they intend to exploit their recent find of billions of barrels of shale oil for all it’s worth!

  2. Vic says:

    “Well it’s only a whimsical notion, to fly down to Rio tonight. No I probably won’t fly to Rio, but then again I just might.”

  3. Rabid Doomsayer says:

    Australia is not going to take climate change seriously until Sydney has a summer so brutal, that the electricity grid fails due to air-conditioning demand.

  4. Merrelyn Emery says:

    Thanks for those articles Vic. They make it perfectly clear that the situation is very different from that perpetrated by some of the Superpeople amongst us. The coal boom is over as more people turn to renewables, ME

  5. Merrelyn Emery says:

    Have you been to Oz? Air conditioners are nowhere near as ubiquitous as they are in the US. And why Sydney? Plenty of places get higher temperatures than Sydney, ME

  6. Vic says:

    Australia now has a sizable amount of mothballed coal-fired generation capacity waiting in the wings to be dusted off and switched back on for just such an occasion.
    What I find more alarming was a precedent set last year, where fire conditions reached such dangerous levels that one electric utility in South Australia purposely switched off their electricity supply in the fear that their powerlines might ignite a fire. Luckily on the day, nobody required the use of an electrically powered pump to extinguish any small fire before it got out of control. It kind of reminds me of the recent events in Lac Megantic, where firefighters switched off the engine in a burning locomotive – the same engine that was supplying power to the train’s air brakes…

  7. Superman1 says:

    “The coal boom is over”. The reference above states: “In 2011, Australia’s thermal coal exports grew by four %, relative to 2010, to total 148 million tonnes. Projections for 2012 see an increase of 10% in 2012 to 162 million tonnes, then growing at an average annual rate of 11 % between 2013 and 2017, to total 271 million tonnes by the end of the period.” That’s your definition of ‘over’?

  8. Brooks Bridges says:

    Might work for the US if it happened in DC

  9. Brooks Bridges says:

    I think it was Hansen who showed that actual data show the curve doesn’t just move to right but also flattens.

    So the tails become a larger portion of the total area. Which increases the frequency of above-normal temps. I think this is related to the overall increase in climate variability.

    And heat waves have proved a major killer.

  10. Superman1 says:

    “And this is only from 0.8 C warming. Its really hard to imagine the “climate goal” of 2 C warming as a safe level. I’d say 0.8 is already way too much for our society to handle. I wonder what kind of catastrophe it would take for people to understand this?” From one of the posters on your link; this says it all, and is a good illustration of what it means to be ‘serious’ about ameliorating climate change.

  11. Merrelyn Emery says:

    The projections are based on the past. The reality is that businesses are closing as the bottom has dropped out of the market as demand declines, ME

  12. FrankD says:

    If Australia mines coal to ship to China so they can manufacture goods to sell to US/European consumers, who is really to blame for those emissions?

  13. Aussie John says:

    AGW is beyond politics:-
    Someone should get those GOP senators and bang their heads together perhaps it may drive some reality into their thick skulls!!

    Only stupid arrogant people can ignore such warnings as above.
    The problem is REAL!!

    It is not a laboratory test run – it is our one and only Earth.