The Angry Summer: Report Blames Climate Change For Australia’s Extreme Weather
By Jeff Spross on Mar 5, 2013 at 4:42 pm
 The Australian government’s Climate Commission — an independent panel of experts set up by the government but not subject to its direction or oversight — issued a new report on Monday labeling Australia’s latest summer season the “Angry Summer” in honor of the rash of brush fires, heat waves, torrential rains and flooding that pounded the country.
“Australia has always been… a land of extremes,” the report said, but global warming of 0.8 degrees Celsius over the last 100 years and the resulting climate change is now driving the extreme weather to new heights. “All extreme weather events are now occurring in a climate system that is warmer and moister than it was 50 years ago,” the report warned. “The basic features of the climate system have now shifted and are continuing to shift.”
At least 123 weather records were broken during the 90-day time frame examined by the report, including the hottest summer since record-keeping began in 1910, the hottest day for Australia as a whole ever recorded, and the hottest seven consecutive days ever recorded. The commission ran through the severity and influencing factors of each form of extreme weather Australia has seen:
- Record-Breaking Heat: Australia has only seen 21 days in 102 years in which the average maximum temperature for the whole country exceeded 39 degrees Celsius, and eight of them hit this summer. On top of that, the record-breaking heat occurred in the absence of an El Niño — the 12 to 18-month periods of warm, dry conditions that cyclically roll through — which usually has accompanied Australia’s previous hottest summers. Even the small shift in Australia’s average temperature of 0.9 degrees Celsius that’s occurred since 1910 can have profound effects on the severity and frequency of hot weather, as it alters the distribution of extreme weather’s likelihood.
- Brush fires: As many as 40 brush fires tore through Tasmania this summer, destroying around 25,000 hectares of land, 200 properties, and 21 businesses. Other rashes of fires hit New South Wales and Victoria. Climate change can leave soil and plant life drier while extending the life of the fire season. In fact, the Forest Fire Danger Index, the numerical gauge used to assess the threat of brush fires, had to be extended on the high end in 2009 due to the increase in extreme weather.
- Heavy rain and flooding: Unusually heavy rains triggered severe flooding in areas of New South Wales and Queensland this summer, breaking many daily rainfall records throughout the area. The most impressive was the one-day rainfall averaged over the Burnett catchment, which beat out the previous record by almost 70 percent. By raising ocean and air temperatures, climate change increases evaporation and moisture content in the air, resulting in heavier individual rainfalls even as overall precipitation goes down in many areas.
Other extreme weather events Australia dealt with this past summer include tornadoes that touched in Bundaberg and other Queensland townships, as well as two tropical cyclones that hit the north and northwestern coasts of the country.
Tim Flannery, the leader of the commission, told the Australian Broadcasting Corporation that the best way to think about Australia’s extreme weather is to realize the “base line” of the climate has shifted. He then cited an analogy we’ve brought up here at Climate Progress numerous times: “If an athlete takes steroids, for example, their base line shifts. They’ll do fewer slow times and many more record-breaking fast times.”
“The same thing is happening with our climate system,” Flannery said. “As it warms up, we’re getting fewer cold days and cold events and many more record hot events.”
Here’s an illustration of that shift from the commission’s report. Notice the right-ward shift in the “center of gravity” of the distribution of events, and resulting increase in extreme and record-breaking weather:
The good news is that Australia is moving to do what it can about climate change. The latest numbers from Bloomberg New Energy Finance show that the price of wind power is already undercutting that of fossil fuels, and it won’t be long before solar is as well.
“The decisions we make this decade will largely determine the severity of climate change and its influence on extreme events for our grandchildren,” the commission’s report concluded. “In Australia and around the world we need to urgently invest in clean energy sources and take other measures to reduce emissions of greenhouse gases. This is the critical decade to get on with the job.”
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