Wildfire smoke billows behind a mountain range on Tuesday, close to Canberra's southern outskirts. (Rod McGuirk/AP)

Australia’s bush fire crisis is creeping closer to the seat of government, as flames from out-of-control blazes have come within sight of Canberra. One of the fires, burning in Namadgi National Park to the south of Australia’s capital, was accidentally started by a military helicopter used for firefighting.

According to emergency services officials, a landing light on that helicopter sparked a grass fire that quickly grew out of control, doubling in size on Wednesday and threatening homes in the city’s far southern suburbs.

Scientists with Australia’s Bureau of Meteorology are warning that Canberra is in for an “extreme” heat wave from Thursday through Sunday, along with elevated fire danger. Canberra, a city of 400,000 people, lies in an area that is susceptible to bush fires, though the city had largely escaped the flames so far this season and had been mainly affected by poor air quality from bush fire smoke.

There is a state of alert in effect for the Australia Capital Territory (ACT), which encompasses Canberra, in anticipation of the growing fire risk during the next few days.

According to the Bureau of Meteorology, yet another heat wave is building in Western Australia and is moving eastward through this weekend. Thursday through Sunday, the Canberra region can expect extreme heat wave conditions, the highest on the country’s heat wave intensity scale. Temperatures greater than 104 degrees Fahrenheit (40 Celsius) will be commonplace across a wide area of southeastern Australia.

“We have seen this fire behave unpredictably, and we all must think of the worst-case scenario and what we would do to ensure that lives and property are protected, ACT Chief Minister Andrew Barr said at a news conference Wednesday.

The heat will be less dry this time around, thanks to a tropical low that has come ashore along the northern coast of Australia out of the Gulf of Carpentaria. This will ensure that high temperatures remain elevated at night, and strong winds could cause elevated fire-weather dangers in Canberra, Victoria, New South Wales, Tasmania and other areas through the weekend.

Eventually, showers and thunderstorms may erupt and sweep north along a cold front from South Australia into New South Wales by late in the weekend. This could initially cause erratic fire behavior before any beneficial rains fall.

The fires are presenting the greatest threat to Canberra since a 2003 bush fire disaster there that killed four people, injured more than 400 and destroyed about 500 homes, when fires that had been burning near the city roared into town. “There’s challenging times coming up, we’re not going to get this fire out today and not tomorrow. This is a campaign fire, and we’ll be working for some time,” ACT Emergency Services Agency incident controller Matthew Shonk told ABC Radio on Wednesday.

Temperatures in Canberra are forecast to be as high as 108 degrees Fahrenheit (42 Celsius) on Saturday, which, when combined with gusty winds and dry conditions from a long-running drought, will create ideal conditions for bush fires to expand and make rapid advances into populated areas.

Protesters, wearing firefighter uniforms and a mask depicting Prime Minister Scott Morrison, stand outside the National Press Club in Canberra on Wednesday. (Mark Graham/Bloomberg News)

The fires this season have burned vast tracts of forests rich in biodiversity throughout southeastern Australia, harming some unique species. They have effectively doubled the country’s annual greenhouse gas emissions, sent smoke around the world and threatened the political fortunes of pro-coal Prime Minister Scott Morrison, who has downplayed climate change’s role in exacerbating the bush fire season.

Studies unequivocally show that there has been an increase in heat waves and high-fire-risk days in southeastern Australia and that these trends are due in large part to human-caused global warming.

The country was never as hot and as dry at the same time as it was in 2019, which helped set the stage for the devastating fires. In December, Australia recorded its two hottest days on record. On Dec. 18, the nationally averaged maximum temperature was 107.4 degrees (41.9 Celsius), shattering the old record of 104.5 degrees (40.3 Celsius) set in 2013. Australia has warmed by just over 1.8 degrees (1 degree Celsius) since 1910, with most of the warming occurring since 1950. The Bureau of Meteorology has found an uptick in the frequency of extreme heat events and severity of drought conditions during this period, as well.