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. Liberal MP Craig Kelly said climate change had not caused the bushfires ' but that unprecedented arson had. 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 said 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. So, is arson primarily to blame for the bushfire crisis? RMIT ABC Fact Check takes a look at the evidence.