As bushfires continue to cut a devastating swath across millions of hectares, debate has turned to focus on the extent to which arson is to blame.

Social media has been rife with claims that the majority of the fires have been deliberately lit.

A number of prominent politicians and public figures have also suggested that arson, not climate change, is the main cause.

In a recent interview, controversial Liberal MP Craig Kelly said climate change had not caused the bushfires — but that unprecedented arson had.

"We know you need some form of ignition," he told ABC Radio's RN Breakfast.

Key points: There is no evidence that arson has reached "unprecedented" levels

There is no evidence that arson has reached "unprecedented" levels Lightning strikes appear to be responsible for most fires in the current crisis

Lightning strikes appear to be responsible for most fires in the current crisis In general, fires caused by arson are typically smaller and closer to roads

In general, fires caused by arson are typically smaller and closer to roads Experts say arson cannot explain the scale of the current crisis, pointing to drought and heat exacerbated by climate change

"Now the majority of these fires, we've had unprecedented numbers of people being arrested and charged with arson offences. The arson is not caused by climate change."

In a January 4 interview on ABC News Channel, Tasmania Liberal senator Eric Abetz also referred to "unprecedented" levels of arson in relation to the bushfire crisis.

And Nationals MP George Christensen said in a Facebook post that the cause of the fires was "certainly" man-made, but "it's just not man-made climate change. It's man-made arson that, to me, almost borders on terrorism".

Meanwhile, West Australian mining billionaire Andrew Forrest, having announced a $70 million donation for bushfire recovery and resilience measures, said while he did not want to politicise the crisis, he believed arsonists played the "biggest part" in starting bushfires.

Mr Forrest subsequently issued a statement clarifying his position, saying he unequivocally accepted the warming of the planet as a primary cause of the catastrophe.

"I do not want people to think that criminal behaviour, while reprehensible, is the main reason for the devastation this bushfire season," he said.

"Arson may be responsible for starting fires in some cases, but it is not the reason the fires have reached the proportions they have through this season and it is not the reason they have continued for so long."

Is arson primarily to blame for the bushfire crisis? RMIT ABC Fact Check takes a look at the evidence.



What is arson?

As noted by the Black Saturday Royal Commission, in a legal sense "arson" is an indictable offence that involves deliberate fire-setting resulting in criminal damage to property, including a structure, a house, a vehicle or vegetation.

Arson also involves the "requisite intention" to cause damage or have no regard for the damage that might result from a fire.

Many bushfires, for example, are the result of negligent or illegal behaviour by people ignoring total fire bans or throwing away lit cigarettes and matches.

However, this type or behaviour generally does not meet the legal or technical definition of arson.

The Black Saturday bushfires killed hundreds of people across Victoria. ( AAP: Andrew Brownbill )

A difficult crime to detect and analyse

Assessing the extent to which bushfires are caused by arson is tricky.

Various jurisdictions and government agencies have different approaches to defining and recording fires that are deliberately lit.

As the Black Saturday Royal Commission report put it: "Some jurisdictions adopt a broad definition, deeming all suspicious fires to be arson; others might limit the term to those fires for which there is a prima facie, or even a proven, case of arson."

According to experts contacted by RMIT ABC Fact Check, this inconsistency has changed little in the years since that report was handed down.

Identifying the cause of a bushfire can be difficult, given fires often start in remote or secluded places.

Bushfires often start in remote or secluded areas. ( Supplied: Jane Watson, The Oxygen Farm )

Melbourne University Associate Professor Janet Stanley, a leading expert from the National Centre for Research in Bushfire and Arson, said about 40 per cent of fires had no assigned cause, and less than 1 per cent of arsonists were caught and convicted.

"I don't think we can know at this point how this current round of fires started," Professor Stanley told Fact Check.

"Unless people were there and picking a person up on the spot lighting the fire, arson is very hard to detect because it tends to be committed away from people in a quiet spot in the bush.

"Often the fire itself destroys any evidence, so it's a very hard crime to detect, and getting evidence to prosecute and get a conviction is difficult."

Australian research into the causes of bushfires and the extent to which arson is to blame is relatively scant.

A February 2008 report by the Australian Institute of Criminology estimated that, of bushfires with known causes, 13.3 per cent were maliciously lit.

A further 36.2 per cent were deemed "suspicious". About a third, 35 per cent, were found to be "accidental" — started, for example, by children or smokers.

"Difficulties exist in determining how the numbers of deliberate (incendiary and suspicious) fires have changed over time, due to changes in database collection methods, difficulties in integrating databases, the considerable uncertainty in the causes of many fires and complexities in delineating the specific cause of particular temporal variations," the report noted.

Troy McEwan, an associate professor in clinical and forensic psychology at Swinburne University, said in an interview on ABC's RN Breakfast that arson was responsible for a significant proportion of fires in Australia, although it was not helpful to attribute the majority to arson.

Associate Professor McEwan offered the example of the February 2009 Black Saturday fires, which killed 173 people.

Initially, four of the fires were thought to have been caused by arson, leading to 52 of the 173 deaths.

"Subsequently, only one of the fires on that day was actually attributed to arson and that caused 10 deaths," Associate Professor McEwan said.

"And that's obviously horrific and bad enough but we can't jump to conclusions too quickly.

"I think we need to be open to the idea that it could be caused by arson but, equally, it's not helpful to say these fires are always caused by arson or the majority of them are because the reality is, it seems, that most very large fires are not caused by arson."

Has bushfire arson risen to an 'unprecedented' level?

In Victoria, the Crime Statistics Agency publishes information on offences in relation to bushfires.

The offence is divided into three subcategories: intentionally cause a bushfire; recklessly cause a bushfire; and recklessly spread a fire to vegetation.

The latest data is for the year to September 2019, with no official figures covering the current bushfire crisis yet available.

Over the 12 months to the end of September 2019, Victoria Police recorded 21 offences involving a person intentionally causing a bushfire.

Far from representing an "unprecedented" level of bushfire arson, that was the lowest level for at least a decade, and well below the 10-year average of 49.5 offences.

Victoria Police has also contradicted suggestions that the current bushfire crisis has been overwhelmingly caused by arsonists.

A Victoria Police spokeswoman said: "There is currently no intelligence to indicate that the fires in East Gippsland and the north-east have been caused by arson or any other suspicious behaviour."

The Country Fire Authority (CFA) has also reportedly said the recent fires were not caused by arson.

The CFA incident controller in Bairnsdale, Brett Mitchell, pointed to lightning as the cause of most of the fires.

Likewise, in NSW, emergency services personnel have blamed lightning strikes for most of the fires.

"I can confidently say the majority of the larger fires that we have been dealing with have been a result of fires coming out of remote areas as a result of dry lightning storms," NSW Rural Fire Services Inspector Ben Shepherd was quoted as saying.

The New South Wales Bureau of Crime Statistics and Research provided Fact Check with unpublished data on the number of people suspected of bushfire arson facing police action.

These figures show over the year to September 2019, 56 people faced police actions in relation to alleged offences regarding the lighting of a fire, lower than the decade average of 68.7 people.

According to a January 6 statement released by NSW Police, since November 2019, legal action ranging from cautions through to criminal charges had been taken against 183 people in relation to bushfires.

However, it is wrong to suggest, as some people have done, that this figure relates solely to bushfire arson.

The vast bulk of this action related to other offences such as failing to comply with fire bans and the discarding of lit cigarettes and matches.

Of the 183 people who face legal action in NSW, only 24 (representing 13 per cent of the total) were charged with deliberately lighting bushfires.

A further 53 people (29 per cent of the total) faced charges or a caution for failing to comply with a total fire ban; 47 (26 per cent) faced charges or were cautioned for throwing away a lit cigarette or match on land.

Fact Check was unable to access separate data for "bushfire arson" (as opposed to "arson" more broadly) in Queensland.

In a statement, Queensland Police said a taskforce had been established in September 2019 to investigate fires.

It suggested about 11 per cent of bushfires reported in Queensland between September 10, 2019 and January 8, 2020 had been found to have been deliberately lit.

"As at January 8, 2020 there have been 1,068 reported bushfires in Queensland since September 10, 2019," the statement said.

"Of these, 114 fires have been deliberately or maliciously lit through human involvement and have been subject to police enforcement action."

It said 109 people (including 36 adults and 73 children) had been dealt with by police across Queensland for offences relating to recklessly and/or deliberately setting fires.



Deliberately lit bushfires are likely to be smaller

Although not always the case, evidence suggests that so-called "natural fires" — generally started by lightning strikes — are likely to be much larger and more remote than fires started by arsonists.

University of Tasmania Professor of Environmental Change Biology David Bowman, a leading bushfire expert, told Fact Check that many of the big fires in the current crisis were known to have been caused by lightning strikes, having originated in remote areas after lightning storms.

"We know there are lightning storms that have caused these fires," Professor Bowman said.

"One of the signatures of arson is that arson [occurs] in proximity to people. Many of these fires have been burning in remote and inaccessible areas, so there is a significant lightning component."

Swinburne University's Professor McEwan told Fact Check that smaller fires on urban fringes were more commonly linked to arson.

Fires on the urban fringes are more commonly associated with arson, rather than those lit in regional areas, according to experts. ( AAP: State Government of Victoria )

"What we do know is that larger vegetation fires that occur further from urbanised areas are less commonly attributable to deliberate fire-setting than are smaller vegetation fires that occur on the urban-rural fringe," she said.

This was backed by an Australian Institute of Criminology study, which analysed about 280,000 fire incidents attended by 18 different Australian fire services.

It concluded that natural fires tended to be much larger than deliberately lit fires, which typically occur nearer to populated areas and roads, meaning they tend to be contained more rapidly.

"[D]eliberate fires typically comprise a decreasing proportion of all fire causes as fire size increases, whereas natural fires comprise higher proportions of larger fires," the report noted.

"Deliberate fires resulting from illegal burn-offs are on average larger than deliberate fires resulting from vehicle arson or other incendiary activities."

The bottom line: Australia is getting hotter and drier

There is no doubt that arson is responsible for a significant number of fires in Australia.

However, the data does not yet exist to accurately dissect the current bushfire crisis. According to experts consulted by Fact Check, that could take some time.

What evidence there is, however, suggests it is highly unlikely arson has been responsible for most of the current bushfires.

Nor is there any evidence to indicate bushfire arson has increased to "unprecedented" levels, as some in the Morrison Government have suggested.

In Victoria, the number of intentionally caused bushfire arson offences peaked in 2016, but had fallen to a level well below the 10-year average according to the most recently available figures.

Data provided to Fact Check by the New South Wales Bureau of Crime Statistics and Research shows the number of people facing police action for deliberately lit bushfires was below the 10-year average in 2019, having peaked in 2014.

Regardless of how bushfires are started, hotter, drier conditions are exacerbating them, according to bushfire experts.

Professor Bowman, of the University of Tasmania, said even if all of the unexplained fires were attributed to arson, it would not explain the current bushfire crisis.

"It can't," he said. "To try to criminalise the crisis as being caused by arson is not rational, and it also underplays the fact that the reason this fire crisis is so dramatic is because it is a climate and drought-driven event of heatwaves and extreme wind. There is a very strong background of climate and weather."

Principal researcher: Josh Gordon, economics and finance editor





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