Early-season NSW 'catastrophic' bushfires are a sign of more to come over summer

The NSW bushfires have been described by Premier Gladys Berejiklian as “some of the most devastating bushfires we have ever seen”, prompting her to declare a state of emergency, the first since 2013.

Already, the fires in NSW and Southern Queensland have burned more than 850,000 hectares and killed three people, with fears that number will rise, as “the worst is yet to come”, according to the NSW Rural Fire Service.

A catastrophic warning is now in place for Greater Sydney and Greater Hunter, with hot and windy conditions and temperatures forecast to soar into the mid-30s on Tuesday.

“Catastrophic is the highest level of bushfire danger. Homes are not designed to withstand a fire under these conditions,” the NSW Rural Fire Service said.

“The fire danger tomorrow [Tuesday] is now expected to be worse than originally forecast,” the RFS tweeted on Monday afternoon, when the Illawarra/Shoalhaven region was added to the risk.

The seemingly unquenchable fires down the eastern coast are feeling increasingly unprecedented, and reminiscent of some of Australia's worst, described by survivors as "apocalyptic beasts".

“The most important message for those immediately affected is to remain vigilant, keep on top of escalating trends as the situation unfolds, leave early if possible, and don't overestimate your powers to fight this,” said Paul Read, a senior lecturer in Monash University’s Faculty of Medicine.

“Apart from sheer size, another take-home message is that the fires burning since October started much earlier than usual and will get worse as summer gets closer. I also think it will expand northwards and southwards across the whole of the eastern seaboard.

“Sadly, I expect more deaths by dint of size and, despite their best efforts, the stretching of emergency service capabilities, quite apart from burns and immediate respiratory deaths," he said.

“Apart from destroying life, homes and habitat, it will be affecting human, plant and animal health, even outside of the fire paths.”

"It’s unprecedented in terms of seasonality, but so far it’s only half the size of Australia largest recorded fire [Black Saturday, 1939]."

An air quality index (AQI) above 300 is considered hazardous to everybody, not just the vulnerable, and usually prompts a community alert, as it can lead to life-threatening medical emergencies.

“In the past week or two, we've already seen AQIs beyond this range in the Hunter, Central Coast, Sydney and Illawarra regions."

He said that on Saturday, parts of Queensland reached levels up to 407, which is much higher than most of Indonesia during last month's Borneo fires.

Is climate change playing a role in the fires?

“The jury is always out when it comes to science, as it should be, but I'd lay bets that it's climate change affecting our seasons, Dr Read said. “And this is scary for everybody.

“We need to sensibly, gently (but rapidly) adjust our ways of doing economics and politics worldwide, at the same time strengthening our capacity to cope with natural and man-made disasters. Bushfires are, after all, a combination of both.”

“On a much longer time frame, the world is supposed to be entering a cold snap based on the Milankovitch cycle, but temperatures around the world have been setting records for hottest years, and even decades."

He said to understand the role of climate change in these fires, “we first need to see where each and every Australian climate driver is sitting at present.

“An anomaly outside of their combined effects – and there have already been several temperatures much higher than seasonally expected – could suggest climate change, especially if the evidence for other anomalies emerge from, for example, farmers' and firefighters' datasets alongside bureau meteorological trends.

“At present, we're coming out of a negative Southern Annular Mode that's caused drought from hotter west winds, so the fuel load is already crisp, and we've been getting deeper into the hot cycle of the El Nino southern oscillation since late 2018.

“On a much longer time frame, the world is supposed to be entering a cold snap based on the Milankovitch cycle, but temperatures around the world have been setting records for hottest years, and even decades.

“These fires are unprecedented in terms of seasonality, but so far are only half the size of Australia largest recorded fire [Black Saturday, 1939]. That said, the fires would be pumping out the same carbon emissions of all the world’s volcanoes combined annually.”

Dr Paul Read was a senior lecturer at Monash University at the time of writing this article.