This summer’s fires had devastating impacts on landscapes and local economies.

For the first time in eight months, all the NSW fires are out. The Namadgi fires are out, as are the fires in north east Victoria and East Gippsland. During the fires, there was an attempt by some groups to blame the fires on arson as a way of avoiding the conversation about climate change. There is the ongoing debate about the role of fuel reduction burning as a way to reduce the intensity of fire, plus the broader conversation about how we manage our forests and wild places, and whether salvage logging of burnt areas should be allowed.

Now, a ground-breaking report has shown that climate change was a ‘massive factor’ in the extreme fire conditions that devastated Australia this summer.

The report was prepared by World Weather Attribution (WWA), which ‘is an international effort to analyse and communicate the possible influence of climate change on extreme weather events, such as storms, extreme rainfall, heatwaves, cold spells, and droughts’.

10 Daily reports that:

According to some official fire danger ratings, Australia’s risk of having a fire season as bad as this years has increased by nine times, compared to 1900.

“Climate change contributed to the fires and extreme heat we lived through in southeastern Australia,” Canberra climate scientist Dr Sophie Lewis said.

“(It) is now part of Australia’s landscape. Extreme heat is clearly influenced by human-caused climate change, which can influence fire conditions.”

The study noted 2019 was Australia’s warmest and driest year since observations began in the early 1900s.

Combined with the long-term Indian Ocean Dipole weather effect, this “led to weather conditions conducive to bushfires across the continent and so the annual bushfires were more widespread and intense and started earlier in the season than usual”, the authors wrote.

The study found heatwave conditions of the severity of that experienced during Australia’s 2019/20 summer would have been several degrees cooler, and far less likely, in the year 1900.

According to reporting by Bob Berwyn in InsideClimateNews,

Human-caused warming increased the chances by at least 30 percent for the extreme fire weather that dried out soil, grass, brush and trees, the research found. The heat buildup caused by greenhouse gases probably played an even bigger role than the researchers were able to demonstrate, said University of Oxford climate scientist Friederike Otto, one of the authors of the new study, released Wednesday. 

“We found that it was at least 30 percent, but it’s likely much higher because the models underestimate extreme heat trends, one of the very important parts of the equation,” Otto said. 

the scientists analyzed weekly, monthly and seasonal fire-weather measurements across the areas that burned most intensely, between the Great Dividing Range and the sea in New South Wales and Victoria. 

The findings include a sharp increase in the risk of fire weather since 1979. More long-term, the overall probability for dangerous fire conditions has increased more than four times since 1900. The chances of high fire danger in any one month have increased ninefold, the study found, and if the average global temperature increase reaches 2 degrees Celsius (3.6 degrees Fahrenheit), fire weather like this past summer would be at least four times more likely, compared to 1900. The researchers also found that:

  • Global warming has increased the warmth of heat waves by 1 to 2 degrees Celsius (1.8 to 3.6 degrees Fahrenheit) since 1900.
  • A heatwave of this intensity is at least 10 times more likely now than it would have been around 1900.
  • The observed trend of extreme weather is outpacing the trends predicted by climate models. 
  • There is no attributable trend in Australia toward extremes of dry weather like the ones observed in 2019.
  • The extreme fire weather conditions of 2019-2020 were intensified by record-setting shifts in regional weather patterns.

There is evidence that human-caused climate change is also increasing the fire risk in ways that the attribution study didn’t capture, said Nerilie Abram, a climate extremes researcher with Australian National University and the Australian Centre of Excellence for Climate Extremes.

Research suggests that global warming is intensifying the Indian Ocean Dipole, an oscillation in sea surface temperatures similar to the Pacific’s El Niño, which increases fire risk in south eastern Australia. Human-caused warming is also shifting winter rainstorm tracks away from southwest and southeast Australia, said Abram, who was not involved in the new study”.

What now?

It is clear that unchecked climate change will continue to make our fire seasons longer and more intense.

In ecological terms, it is vital that we limit the impact of fires on the high elevation snow gum woodlands, excluding fire wherever possible.

Some obvious responses to reduce future impacts include:

  • Continue to invest in air support to fight fires in remote areas, with continued resource sharing between the states and overseas jurisdictions, to access additional planes and helicopters when needed
  • Continue to increase the number of paid seasonal firefighters, including additional allocation of funds and training to expand the number of remote area firefighters
  • The federal government should establish a national remote area firefighting force which can be deployed as needed across Tasmania and mainland states when World Heritage and National Parks are at risk. This was recommended by a Senate inquiry after the devastating fires in Tasmania of 2016.
  • A fourth option to consider is to develop a new volunteer firefighting force specifically tasked with adding capacity to state government firefighting agencies when fires threaten national parks, wilderness and World Heritage Areas.