Australian Greens leader Richard Di Natale announced on Monday he is quitting politics to give a new leader of his environmentally-focused minority party an opportunity to expose government failings during the nation's wildfire crisis.

Di Natale's surprise resignation means that both the Greens and the government's junior coalition party, the Nationals, will elect new leaders when Parliament resumes for the first time this year on Tuesday.

Di Natale, a 49-year-old senator, said there was no single reason why be had decided to resign on Monday as party leader. He listed among the factors behind his decision his desire to spend more time with his family and his concern about leaving his wildfire-prone home in Victoria state to sit in Parliament.

"We have as a nation just endured one of the most horrific events in the nation's history," Di Natale told reporters at Parliament House, referring to wildfires that have killed at least 33 people and destroyed more than 3,000 homes since September.

"This is now an opportunity for a new leader to step up at a time when the nation's focus is on this place and to really demonstrate that we are a party brimming with talent, where a new leader can stamp their authority over a government that has been catastrophic in their failures to respond to this horrendous crisis," Di Natale added.

Prime Minister Scott Morrison's conservative government has been accused of being too slow to respond to the wildfire crisis and of not doing enough to reduce Australia's greenhouse gas emissions.

Agriculture Minister Bridget McKenzie resigned from Cabinet on Sunday for breaching ministerial rules by failing to declare she was a member of a gun club that she gave a government grant of 36,000 Australian dollars ($24,100).

Her resignation means Nationals lawmakers will meet to elect a new deputy party leader around the same time that the Greens choose their own new leader.

But former Nationals leader Barnaby Joyce said on Monday he would nominate for his old job if both the positions of party leader and deputy leader are put to a vote.

Nationals leader Michael McCormack said he did not expect his position would be put to a vote, but was confident of defeating any challenge.

Whoever leads the Nationals becomes deputy prime minister and acts as prime minister when Morrison is overseas.

Both the Nationals leader and deputy leader are also guaranteed seats in Cabinet.

Joyce had not been a minister since he quit as Nationals leader in 2018 over controversy surrounding him having a child with a former staffer and allegations that he had sexually harassed another woman.

The first day of Parliament on Tuesday will be dominated by debates about the unprecedented wildfire that is devastating Australia's southeast.

Di Natale said he would quit the Senate once his party had selected a replacement senator.

What's to blame for scores of wildfires devastating Australia's southeast?

There's an increasingly bitter face-off between those who say arson and those who fault climate change.

Each side has powerful backers and their weapons of choice are often fabrications and part-truths that have spread in time with the fires in recent weeks.

Humans burning fossil fuels and humans with criminal intent who torch a combustible landscape both factor into this unprecedented crisis.

But just how to accurately apportion the blame has become a big political issue. The debate is made hotter by many — including some Australian lawmakers — who argue against deeper cuts to carbon gas emissions.

Firefighters blame lightning strikes for most of the major blazes in New South Wales and Victoria states, and many scientists say climate change is the main reason for fires that have claimed at least 33 lives since September, destroyed more than 3,000 homes and razed more than 1 0.6 million hectares (26.2 million acres ).

Still, the arson side often cites repeatedly on social media a debunked statistic that says more than 180 suspected arsonists have been arrested.

"Truly Disgusting that people would do this! God Bless Australia," President Donald Trump's son Donald Trump Jr. tweeted. "More than 180 alleged arsonists have been arrested since the start of the bushfire season," he added.

Although it's been discredited by AAP FactCheck, the fact-checking division of news agency Australian Associated Press, the statistic has been repeated thousands of times online.

A AP FactCheck, a partner in Facebook's Third Party Fact Checking program, looking at misinformation on Facebook and Instagram, links the statistic to a statement by police in New South Wales — the worst fire-affected state — that said "legal action" had been taken against 183 people since November for "bushfire-related offenses."

These included only 24 people charged over "deliberately-lit bushfires." Legal action — which includes cautions — had also been taken against another 100 people for conduct that could be described as being careless during a fire ban.  The statement did not detail the offenses alleged against the remaining 59 suspects.

Climate change is the main reason for the current extraordinarily destructive fire season, according to Janet Stanley, a director of Australia's National Center for Research in Bushfire and Arson.

"In the past, there's been little interest generally in why people light fires -- whether it's purposefully or accidentally or maliciously or recklessly -- because climate change hadn't kicked in and it really wasn't such a problem because fire could fairly easily be put out," said Stanley, who has studied arson-related wildfires for three decades.

"But because of climate change, this is not the case now. The conditions that make a fire very big and dangerous and spread quickly are now a great deal worse, so it's much harder to put out the fire once it occurs than it was in the past," she added.

Arson has long been part of Australia's wildfire seasons, but it's hard to estimate how big a problem it is because crime scenes are often remote and evidence is frequently destroyed.

The New South Wales Bureau of Crime Statistics and the Victorian Crime Statistics Agency won't release their arson data for the current wildfire season in the two worst-effected states until March.

Swinburne University of Technology arson expert Troy McEwan cautioned that three fires that killed 42 people in Victoria during a wildfire emergency in 2009 had initially been wrongly blamed on arson.

"Certainly a significant proportion of bushfires are deliberately lit in Australia," she told Australian Broadcasting Corp.

"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," she added.

Australian Deputy Prime Minister Michael McCormack believes arsonists are the major problem.

"It's important to note that most of these fires have been caused by little Lucifers running around with matches and fire-starters and creating havoc," McCormack told reporters, referring to child arsonists, while acknowledging that climate change was also a factor in the fire emergency.

McCormack's rural-based party, the Nationals, is staunchly against any action on climate change that would carry an economic cost, such as making polluters pay for the carbon gases that they emit.

Some lawmakers in Prime Minister Scott Morrison's conservative Liberal Party publicly dispute any link between climate change and the fires.

A common theme being spread by those looking to exaggerate Australia's contribution to global warming "was that the fires are basically spontaneously occurring because the carbon dioxide in the air is exploding," said Craig Kelly, a conservative lawmaker. "That's nonsense.'"

"There are groups in our society that have exploited these bushfires to push their own political barrow. The climate change alarmists want to hijack the debate and use these fires as an example," Kelly added.

A widely circulated online image purporting to be a NASA satellite photograph shows the wildfires, which are largely confined to southern Australia, extending across the country's tropical north coast. The creator of the image, Anthony Hearsey, explained on his website that it was a digital compilation of almost eight months of NASA fire data and that not all the fires were still burning, but those qualifications were lost online.

Singer Rihanna tweeted the dramatic image to her many followers with the comment: "devastating"

Tourism Australia, a government agency tasked with promoting the country overseas, has included its own fire map on its website to counter online images suggesting much more of the country is ablaze.

Queensland University of Technology researchers Tobias Keller and Timothy Graham suspect automated programs called bots have been used to bolster the apparent popularity of #ArsonEmergency compared to other popular hashtags on the wildfires. The research doesn't identify who is behind the campaign.

Keller, an expert on the spread of political messages on social media platforms, said the involvement of the U.S. president's eldest child was an important achievement for those who overstate the arson problem.

"When someone like Donald Trump Jr. or any celebrity endorses such a narrative, it can gain traction very quickly because everyone looks at what these celebrities post on and what their opinions is and that can be very dangerous." Keller said.

The Australian capital region declared a state of emergency on Friday because of an out-of-control forest fire burning erratically to its south.

It's the first fire emergency for the Australian Capital Territory area since 2003 when wildfires killed four people and destroyed almost 500 homes in a single day.

The threat is posed by a blaze on Canberra's southern fringe that has razed more than 21,500 hectares (53,000 acres) since it was sparked by heat from a military helicopter landing light on Monday, the Emergency Services Agency said.

"The state of emergency sets a clear expectation for our community that we need you to be vigilant," Emergency Services Minister Mick Gentleman told reporters. "This is the worst bushfire season in the ACT since 2003."

The fire is burning at emergency level -- the highest on a three-tier scale of danger -- and embers have created dangerous spot fires nearby, agency officials said.

Residents of southern Canberra suburbs and surrounding villages have been advised to prepare to either protect their homes or evacuate.

Roads were blocked to the village of Tharwa late Friday because the fire posed too much danger for residents to evacuate or return to their homes.

The fire is the most dangerous of dozens of blazes burning Australia's drought-stricken southeast.

Unprecedented fires across southern Australia have claimed at least 33 lives since September, destroyed more than 3,000 homes and razed more than 10.6 million hectares (26.2 million acres).

The fire danger is forecast to escalate across the southeast in the Australian Capital Territory and the states of New South Wales and Victoria as summer temperatures rise over the weekend.

The state of emergency gives Canberra's local government additional powers to block roads, direct people's movements, control their property and undertake firefighting work on private land.

A wildfire sparked by a military helicopter helping firefighting efforts was blazing out of control and threatening homes on the outskirts of Australia's capital on Wednesday  as fire danger escalated across the country's southeast.

The fire had spread over 9 ,500  hectares ( 23,500  acres) since it was started by a transport helicopter landing light that ignited grass in a national park south of Canberra on Monday afternoon, authorities said.

The fire was downgraded from emergency level to the second level on a three-tier danger scale overnight, but it remained out of control, the Emergency Services Agency said.

The village of Tharwa was under threat on Tuesday with drifting embers starting spot fires ahead of the fire front. Emergency services personnel knocked on doors in Canberra's southern suburbs on Tuesday night telling residents to prepare in case they had to evacuate.

Authorities have warned Canberra that the fire poses the greatest threat to the city of 420,00 people since 2003, when an inferno killed four people and destroyed almost 500 homes in a single day.

More than a dozen Tharwa residents chose to stay and defend their homes rather than evacuate, Tharwa Country Store owner Kevin J effer y said.

"We're pretty comfortable that we've got some good support here," Jeffery said, referring to Canberra firefighters deployed in the village.

Army Lt. Gen. Greg Bilton said military helicopters involved in supporting firefighters would no longer use their landing lights after sparking the blaze during a reconnaissance mission.

"It's important that we continue our operation in support of emergency services," Bilton said.

Canberra's airport was temporarily closed last week by a wildfire that threatened homes on its northern fringe. That fire has been extinguished, but the southern fire is expected to burn out of control for weeks.

Fire conditions are forecast to worsen across much of drought-stricken southeast Australia with temperatures forecast to rise in the coming days.

A unprecedented fire season has claimed at least 33 lives since September, destroyed more than 3,000 homes and razed more than 10.6 million hectares (26.2 million acres).

Former Premier League stars Didier Drogba, Dwight Yorke and Park Ji-Sung are among an initial group of international footballers confirmed for an exhibition match in Sydney in May to aid in the country's recovery from devastating wildfires.

The first release of players for the 'Football for Fires' match, which will be played at Sydney's Olympic Stadium on May 23, will also include Emile Heskey, Dario Simic, Geremi, Pedro Mendes, Major League Soccer striker Dwayne de Rosario and former Juventus stars David Trezeguet and Claudio Marchisio.

Several Australian 'Socceroos' will also participate, including former Manchester United and Chelsea goalkeeper Mark Bosnich, John Aloisi and recently retired captain Mark Milligan.

Football Federation Australia said in a statement Tuesday "all proceeds from the match will go toward the restoration and improvement of local football clubs and facilities in fire-affected areas nationwide."

The wildfires have claimed at least 33 lives in Australia since September, destroyed more than 3,000 homes and razed more than 10.6 million hectares (26 million acres). That's an area larger than the U.S state of Kentucky.