Just a week after enduring one of its hottest December heat waves on record, much of Australia is bracing for another round of punishing, dry heat and bush fire dangers through the weekend and into next week.
The new heat wave is forecast to be “extreme,” the most severe designation on the Australian Bureau of Meteorology’s forecast scale. Such heat waves pose a health “risk for anyone who does not take precautions to keep cool, even those who are healthy,” the BOM states on its website.
The hottest areas will be in inland South Australia on Friday and Saturday, while southeastern Australia, which has been severely affected by deadly bush fires that have burned an area nearly twice the size of Connecticut, is forecast to heat up by Sunday into Monday.
In Sydney, the high temperature is forecast to be close to 95 degrees Fahrenheit (35 Celsius) on Sunday, although inland regions closer to the fire’s front lines could soar into the 100s.
The Rural Fire Service in New South Wales is predicting “very high” fire danger over the weekend, with “deteriorating weather conditions” early next week as hot, dry weather takes hold.
“Extreme intensity” heat wave conditions are probable for northern parts of Western Australia, the southeast portion of New South Wales, and far eastern Victoria during the three-day period starting Saturday, the BOM forecasts. For example, Canberra, the nation’s capital, is forecast to reach 100 degrees Fahrenheit (38 Celsius) over the weekend.
The typical high temperature in Canberra during the month of December is 81.5 degrees (27.5 Celsius).
The heat is predicted to extend into the first week of the new year, which begins what is typically the country’s hottest month. However, it may be difficult for Australia to eclipse the records set in December, with numerous all-time heat records falling in individual locations, and the country setting records for its hottest day ever measured.
The country is in the grips of a serious drought, which is exacerbating the hot conditions as more of the sun’s energy goes into heating the air rather than also evaporating water from vegetation. The extremely dry conditions have allowed tree types that typically do not burn to go up in flames as bush fires have raged for months along the eastern coast of Australia.
One fire, known as the Gospers Mountain blaze, measures more than 1 million acres in size. The result of several fires combined, it is referred to as a “mega fire” and has been burning on the outskirts of Sydney, sending a plume of hazardous smoke into the country’s most iconic city week after week.
The heat and fires have become a political flash point in Australia, where the Liberal-National coalition government of Scott Morrison has come under fire for its strident support of coal production and refusal to reevaluate climate policies in the wake of the bush fires.
Australia is a leading coal exporter, and burning coal to generate electricity is a major source of greenhouse gases that cause global warming.
Telltale climate fingerprints
Human-caused global climate change is making heat waves such as this one more likely to occur, more severe and longer-lasting. This year, natural climate variability is combining with climate change to strongly favor dry and hot weather in Australia, particularly in southeastern regions.
An early analysis of the previous December heat event shows that climate change may have made the Australian national heat record at least 20 percent more likely to occur now than in a climate that had not been influenced by human emissions of greenhouse gases. Ongoing research into the event may conclude that it could not have occurred without human-caused global warming, as previous analyses of other extreme heat events have found.
According to a new BOM report on the 2019 bush fires, spring brought the highest fire-weather danger on record in Australia, as measured by the Forest Fire Danger Index, with “record high values observed in areas of all States and Territories.”
Long-term climate trends in Australia show clear warming and an increase in extreme heat events. Last summer, for example, was the country’s hottest on record, and the BOM found that climate change exacerbated extreme heat events as well as droughts during the year.
Australia has warmed by just over 1.8 degrees Fahrenheit (1 degree Celsius) since 1910, with most of the warming occurring since 1950. The BOM has found an uptick in the frequency of extreme heat events and severity of drought conditions during this period.
One of the most robust conclusions of climate science research is the link between general warming and increased occurrences and severity of extreme heat events.