Lies have spread faster than grassfire during Australia’s unprecedented national emergency.

They’ve ranged from the exaggerated to the outrageous.

One conspiracy bizarrely claims bushfires have been lit to clear a path for high-speed rail down Australia’s east coast. Others baselessly claim Islamic State is instructing its followers to wage war on the country with fire, that Chinese billionaires are using lasers to clear the path for new cities, or that eco-terrorists are trying to spur action on climate change by manufacturing a catastrophe.

Accompanying these laughable mistruths, though, are more dangerous distortions.

They are the ones being used to deflect from climate change’s role in creating longer, more severe fire seasons.

Two pieces of disinformation stand out from the rest: that an “arson emergency”, rather than climate change, is behind the bushfires, and that “greenies” are preventing firefighters from reducing fuel loads in the Australian bush.

Disinformation has spread across social media, finding its way into major news outlets, the mouths of government MPs, and across the globe to Donald Trump Jr and prominent right-wing conspiracy theorists like Alex Jones.

Esteemed climate change expert professor Will Steffen, a member of Australia’s Climate Council and the inaugural director of Australian National University’s Climate Change Institute, is concerned at how disinformation has spread with such ease.

“In my mind, I think it’s a serious issue and it is potentially very dangerous,” Steffen told the Guardian. “That’s because the bushfire situation is very dangerous … the evidence is overwhelming that climate change is playing a prominent role in worsening bushfire conditions across Australia.

“People who are for whatever reason trying to put out false or extremely misleading information are actually doing a huge disservice to the risk to human life in the future, the risk to property, the risk to the natural world, and indeed the risk to economy.”

Digital rights experts say the disinformation is yet more evidence that social media platforms are failing in their duty to act responsibly.

“We need to see social media platforms playing a greater role in responding to the disinformation being shared on their platforms about the bushfires,” Digital Rights Watch chair Tim Singleton Norton said.

“This needs to happen in tandem with effective government oversight, transparency, and accountability measures, as well as public education campaigns that give people the tools to identify misinformation.”

There are nuggets of truth in some of the disinformation.

Arson has always been a serious problem in Australia, particularly at times of heightened fire danger. Arsonists have been responsible for some of Australia’s worst bushfires, including a blaze during the horrific 2009 Black Saturday fires that killed 10 people, and arson is a common cause of ignition. New South Wales police say they have charged 24 people for lighting bushfires since November.

This time around, though, the role of arson has been grossly exaggerated. Suggestions of an arson epidemic began to ferment on social media at the height of the crisis around New Year’s Day. On Twitter, much of the disinformation centred around the #arsonemergency hashtag.

Queensland University of Technology senior lecturer Timothy Graham, an expert in social media analysis, took a sample of tweets from the hashtag and analysed them for characteristics typically associated with bots and trolls. His findings suggested a clear “disinformation campaign”.

“Australia suddenly appears to be getting swamped by mis/disinformation as a result of this environmental catastrophe, and we are suffering the consequences in terms of hyped up polarisation and an increased difficulty and inability for citizens to discern truth,” Graham told the Guardian.

Claims of an arson emergency were spurred along by some mainstream outlets. Channel 7, a major commercial television network, tweeted that police were “now working on the premise arson is to blame for much of the devastation caused this bushfire season”.

The tweet neither reflected what police had said or what Channel 7 had itself reported in its news story.

A story in the Murdoch-owned national broadsheet, The Australian, also falsely claimed that 183 arsonists had been arrested in the “current bushfire season”. That piece also went global. It was tweeted by Donald Trump Jr and followed up by InfoWars, a right-wing US website, which stated: “Authorities in Australia have arrested close to 200 people for deliberately starting the bushfires that have devastated the country, yet the media and celebrities continue to blame ‘climate change’ for the disaster.”

The number was a gross exaggeration. It was arrived at by counting a range of bushfire-related offences other than arson – including contraventions of fire bans, for example – and used annual figures, not those for the current fire season, which began in September. The Australian subsequently updated its story.

NSW’s Rural Fire Service has said the major cause of ignition during the crisis has been dry lightning. Victoria police say they do not believe arson had a role in any of the destructive fires this summer.

The RFS has also contradicted claims that environmentalists have been holding up hazard reduction work. That claim was running hot on social media, and was given credibility by figures like federal Nationals MP Barnaby Joyce, a prominent Australian politician, who said “green caveats” were stopping firefighters from reducing fuel loads.

This is at complete odds with statements by the RFS commissioner, Shane Fitzsimmons, who said the single biggest barrier to hazard reduction is the increasingly hot and dry weather and the “shrinking window of opportunity” within which managed burns could safely take place.

Fitzsimmons said hazard reduction is also of little utility in fires as intense as those experienced in NSW this season.

“Hazard reduction is absolutely an important factor when it comes to fire management and managing fire in the landscape but it is not the panacea,” Fitzsimmons said on Wednesday.

Comments like Fitzsimmons’ have done little to stop the idea taking hold. Prime minister Scott Morrison has nominated the lack of hazard reduction work as a key issue he wants to investigate after the current crisis.

At the same time, Morrison has demonstrated little appetite for strengthening climate action.