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."
https://www.abc.net.au/news/2020-01...-for-the-bushfire-crisis/11865724?pfmredir=sm
