Australians forced to seek refuge indoors as dangerous smog chokes Sydney

It has become a depressingly familiar sight for residents and tourists: Sydney’s famous Harbour Bridge and Opera House blanketed in smog.

Air quality in Australia’s largest city has been among the worst in the world in recent weeks due to smoke from bushfires, which are raging on its outskirts and across the states of New South Wales (NSW) and Queensland.

On 10 December, air pollution reached 12 times “hazardous” levels in some areas of Sydney.

The southern Australian bushfire season, which typically reaches its height in January and February, started earlier and more ferociously than usual – and the extreme conditions are expected to persist for months.

So far, the fires have claimed at least four lives, forced entire communities to evacuate, destroyed hundreds of homes and almost 3 million hectares of forest and farmland, as well as devastating threatened koala populations and habitats.

Fine particulate matter in bushfire smoke is small enough to enter the lungs and bloodstream, and can increase the risk of asthma attacks, heart attacks and strokes.

In areas affected by hazardous air quality, NSW authorities have advised vulnerable people to stay indoors, with windows and doors shut, and urged everyone to avoid exercising outdoors.

Hospitals have reported a spike in admissions for respiratory problems, schools have kept students indoors and cancelled sporting events and retailers are selling out of face masks.

On smoky days, images of the haze hanging over Sydney, in murky shades of grey, yellow and orange, proliferate on social media – unsettling for a city accustomed to blue skies and ocean breezes.

Smoke particles have even crossed the Pacific and reached South America, according to NASA.

Persistent drought, exacerbated by climate change, has left large parts of NSW and Queensland tinder-dry. Combined with high temperatures and strong winds, this has created the current “catastrophic” fire danger conditions.

The NSW Bureau of Meteorology said the largest fires are “just too big” for water-bombing aircraft or firefighting crews to put out. This includes a “mega-fire” consisting of five blazes that merged north of Sydney.

Former NSW fire chief Greg Mullins said Australians were facing a new age of bushfire danger “supercharged” by climate change.

The unprecedented nature and severity of the bushfire season has intensified pressure on Australia’s federal government for its perceived lack of action on climate change, rising carbon emissions and fossil fuel exports.

Global warming has increased the likelihood and intensity of wildfires around the world, from the Arctic Circle to Indonesia.

Earlier this year, swathes of the Brazilian Amazon were ablaze, with smoke travelling hundreds of kilometres to cities such as São Paulo and Belo Horizonte.

In the United States, large wildfires tear through more than twice the area they did in 1970, and the average wildfire season is 78 days longer.

Ken Pimlott, the former chief of the California Department of Forestry and Fire Protection, said climate change has caused a dangerous “new normal” in wildfire behaviour in the United States and Australia.

With the prospect of a long and exhausting fire season ahead, and potentially worse to come in the future, Australians may have to brace themselves for that new normal.