Australia on Wednesday banned non-essential indoor gatherings of more than 100 people including weddings and restaurants as part a range of measures that could be maintained implemented for more than six months to slow the spread of the new coronavirus.

"This is a once in 100-year type event," Prime Minister Scott Morrison told reporters. "We are looking at a situation of at least six months for how we deal with this. It could be much longer than that. It could be shorter. That is unlikely, given the way we are seeing events unfold."

The indoor limit follows an earlier ban on outdoor gatherings exceeding 500.

Weddings and religious services are regarded as non-essential while health and emergency service facilities are exempt.

Disability and aged care centers are open but restricting visitors. Schools will also remain open, although some medical experts argue for their closure.

Australians have been advised not to travel overseas. Work restrictions on 20,000 foreign student nurses in Australia would be lifted so that they can bolster health resources battling the pandemic.

Australia by Wednesday had 454 confirmed infections among a population of 25 million, but the infection rate is gathering pace.

The virus causes only mild or moderate symptoms, such as fever and cough, for most people but can be severe in some cases, especially older adults and people with existing health problems. People with mild illness recover in about two weeks, while those with more severe illness may need six weeks to recover.

Chief Medical Officer Brendan Murphy said most of the cases were Australians returning from overseas and community transmission in Australia remained "low-level at the moment."

The government announced giving its ailing airlines a 715 million Australian dollar ($430 million) lifeline to help the sector through the pandemic.

A range of government charges will be refunded and waived to help airlines under pressure as domestic and global travel plummet.

The move is expected to create an initial benefit of AU$159 million, with the government refunding charges paid since Feb. 1.

The Airlines for Australia and New Zealand group applauded the government package for a "critical pillar" of the Australian economy and the tourism industry.

The package comes a day after Australia's largest airline, Qantas, announced it would slash its international passenger seats by 90% and domestic capacity by 60% through May at least.

Its major rival, Virgin Australia, announced on Wednesday it would ground all its international flights and half its domestic capacity from the end of March until June 14.

Regional airline Regional Express has urged the government to underwrite the addition debt it will need to survive the downturn.

Plastic waste from the ocean is washing up and increasing pollution on Australian beaches, researchers have found.

In a study published on Wednesday, a team from the Commonwealth Scientific and Industrial Research Organization (CSIRO) and Utrecht University in the Netherlands revealed that plastic waste in the ocean is making its way back to the Australian shore where it is trapped by coastal vegetation.

Denise Hardesty, a Principal Research Scientist from the CSIRO, said that the amount of debris on beaches explains why estimates of waste entering the ocean are 100 times larger than the amount of plastic observed floating on the surface.

"We collected data on the amount and location of plastic pollution every 100 kilometres around the entire coast of Australia between 2011 and 2016," she said in a media release.

"The highest concentrations of marine debris were found along the coastal backshores, where the vegetation begins."

At the beginning of March, Australian Prime Minister (PM) Scott Morrison committed to significantly boosting Australia's recycling capacity, saying that the Pacific has been bearing the brunt of the ocean pollution crisis.

Analysis of the data collected by CSIRO was conducted by a team from Utrecht University.

"The debris recorded along the coasts was found to be a mix of littering and deposition from the ocean," Arianna Olivelli, who led the analysis, said.

"The results suggest that plastic is moving from urban areas into the ocean, and then being transported back onshore, and pushed onto land, where it remains.

"Onshore wind and waves, together with more densely populated areas, influence the amount and distribution of marine debris. The further back we went from the water's edge, the more debris we found."

Australia on Thursday put forward a $17.6 billion (US $11.4 billion) stimulus package meant to stave off a recession due to the impact of the virus outbreak on its economy.

The package includes cash payments for small businesses and welfare recipients to counter the impact of the disease, which has infected more than 126,000 people worldwide.

Australia has recorded 127 cases of the virus and three deaths. The World Health Organization declared Wednesday that the global coronavirus crisis is now a pandemic causing, jolting markets worldwide and raising the sense of urgency surrounding efforts to contain it.

The Australian government will spend 11 billion Australian dollars($7.1 billion) before June 30, the end of the financial year, with the remainder to be spent before July 2021.

Prime Minister Scott Morrison said the package would provide an immediate stimulus to Australia's economy. Up to 6.5 million people — nearly a quarter of the country's population — on government benefits, including pensioners, the unemployed and family tax benefits, will receive one-off payments of 750 Australian dollars each ($485).

"The biggest beneficiaries of that will be pensioners," Morrison said. "They comprise around half of those who will receive those payments."

Morrison said small and medium businesses will receive cash payments of between 2,000 Australian dollars ($1,294) and 25,000 Australian dollars ($16,184) to help pay wages or hire extra staff.

"This plan is about keeping Australians in jobs," he said. "This plan is about keeping a business in business and this plan is about ensuring the Australian economy bounces back stronger on the other side of this and, with that, the budget bounces back with it."

The stimulus package also includes a 1 billion Australian dollar ($650 million) fund to help its embattled tourism sector, which has been sluggish since the wildfires disaster reared late last year.

They were the first stimulus measures in Australia since the global financial crisis more than a decade ago. Morrison's conservative government has been trying to ward off the growing risk of the country's first recession in nearly three decades.

Earlier this month, Australia's central bank cut its benchmark interest rate by a quarter of a percentage point to a record low of 0.5% in response to the outbreak.

The stimulus measures were announced following a 2.4 billion Australian dollar ($1.6 billion) health package, which includes up to 100 coronavirus fever clinics to be set up in areas of need across Australia.

The most senior Catholic to be convicted of child sex abuse took his appeal to Australia's highest court Wednesday in potentially his last bid to clear his name.

Cardinal George Pell was sentenced a year ago to six years in prison for molesting two 13-year-old choirboys in Melbourne's St. Patrick's Cathedral while he was the city's archbishop in the late 1990s.

His lawyers argued in the High Court that an apparently truthful victim was not enough to dispel reasonable doubt about guilt. The seven judges will hear the prosecution case on Thursday on why the convictions should stand.

Pell was convicted by the unanimous verdict of a Victoria state County Court jury in December 2018 after a jury in an earlier trial was deadlocked. A Victoria Court of Appeal rejected his appeal against his convictions in a 2-1 majority decision in August last year.

Pope Francis' 78-year-old former finance minister argued before the High Court that the guilty verdicts were unreasonable and could not be supported by the whole of the evidence from more than 20 prosecution witnesses who include priests, altar servers and former choirboys.

Pell's lawyer Bret Walker told the judges that there had been a "reversal of onus" in which Pell was expected to prove the offending didn't happen instead of prosecutors proving the crimes were committed beyond reasonable doubt.

"That is a wrong question which sends the inquiry onto a terribly damaging wrong route," Walker said.

"Impossible was not something we had to prove, but if we showed it, then obviously there's a reasonable doubt," he added.

Walker said the evidence of a former choirboy, now aged in his 30s with a young family, was the only evidence that Pell had committed the crimes.

Walker said the allegations that Pell had molested the two boys in a priests' sacristy moments after a Mass could not be proved if the jury had accepted the evidence of sacristan Maxwell Potter and Monsignor Charles Portelli.

Potter had testified that the sacristy was kept locked during Masses and Portelli had given evidence that he was always with Pell while he was dressed in his archbishop's robes.

Walker said Pell did not have a five or six minute opportunity required to molest the boys in the sacristy before altar servers and clerics walked in.

"Unlike so many appalling historic sexual misconduct cases, the alleged offending had taken place in a milieu quite different from the usual secluded, secretive or completely private setting," Walker said.

Prosecutors have told the judges in written submissions that it is not their role to determine whether it was open to the jury to find the offending behavior proven beyond reasonable doubt.

Outside court, Pell supporters clashed with a man from a victims advocacy group. Michael Advocate from Victim Justice held signs saying, "Burn in hell Pell."

A group of Pell supporters tried to block Advocate from speaking to reporters, yelling for Pell to be forgiven.

The group of about 50 supporters, many holding Australian flags, sang hymns outside of the court as lawyers prepared for the case inside.

The court will effectively hear Pell's appeal in its entirety before they technically decide whether they will even hear his appeal.

They could decide he does not have permission to appeal, he has permission to appeal but the appeal is denied, or he has permission to appeal and the appeal is upheld.

The judges could also send Pell's appeal back to the Victoria Court of Appeals to be reheard by another three judges.

It is not known when the judges will deliver their rulings.

Pell is serving his sentence at the maximum-security Barwon Prison near Geelong, southwest of Melbourne. He hasn't traveled to Canberra for his appeal hearing.

One of Pell's victims died of a heroin overdoses in 2014 without telling anyone of the abuse.

The survivor went to police after attending his friend's funeral. Neither victim can be identified because the identities of sexual assault victims must be kept secret under state law.

Lisa Flynn, a lawyer for the dead choirboy's father who blames the abuse for his son drug attraction, said her client is "understandably quite anxious and unsettled" by the appeal.

"However he also remains very hopeful and also confident that the High Court will agree with the Court of Appeal majority and that the convictions against George Pell will be upheld," she added.

Climate change raised the chances of Australia's extreme fire season by at least 30%, according to a study released Wednesday by climate scientists at the World Weather Attribution group.

Scientists from Australia, Europe and North America calculated just how much human-caused global warming elevated the likelihood of Australia's record-setting fire season by comparing high-resolution computer models of the continent facing varying levels of climate change.

The scientists took into account differences in climate conditions in about 1900 compared to current conditions — tabulating both measured and observed changes in temperature, drought and fire intensity.

Last year was both the hottest and driest year on record in Australia since measurements began a century ago.

"There is evidence that Australian fire seasons have lengthened and become more intense — and extreme temperatures have played a role in this," said Sophie Lewis, a climate scientist at the University of New South Wales in Canberra, Australia, and a co-author of the study.

"Climate change is now part of Australia's landscape – extreme heat is clearly influenced by human-caused climate change, which can influence fire conditions," she said.

Australia's 2019-2020 wildfire season burned a record 19 million hectares (47 million acres), displacing thousands of people and killing at least 34. The fires also razed rare habitats and killed more than a billion animals, say researchers.

A decade ago, while scientists often discussed how climate change increased the likelihood of extreme weather patterns, researchers were still reluctant to explicitly connect any specific weather event with climate change.

Today, more precise computer models allow scientists to pinpoint the degree to which an altered climate influences the chances of individual extreme wildfires, floods, droughts and heatwaves.

Technology Review magazine – published by the Massachusetts Institute of Technology – recently named climate change attribution models as one of the "Breakthrough Technologies" of 2020.

"It's one thing to paint a broad statistical picture of how climate change is loading the dice for extreme weather events. But it's quite another to really dig into the climate data and specific numbers around an individual disaster, like the Australian wildfires," said Kim Cobb, a climate scientist at the Georgia Institute of Technology in Atlanta, who was not involved in the study.

"Reducing emissions remains the most important way to limit our climate risks," she said.