Climate change rallies: Record-breaking crowds protest government inaction

Over 300,000 students and workers flocked to climate change rallies at 110 locations across the country today.

Public venues overflowed in major cities including at Brisbane's Queens Gardens, where police had to steer the overflowing crowds off the city streets as 30,000 crowded into the city centre.

In Sydney, queues formed as protestors waited in line to join the march, which totalled 80,000 people - filling the Domain.

But the largest crowd was seen as Melbourne's Treasury Gardens, where an estimated 100,000 marched.

Organisers estimate that the crowds were more than double that seen at the previous rally in March, exceeding their expectations of a 50 percent increase in numbers.

Strikers are calling on the government for no new coal, oil and gas projects, including the Adani mine, and to move towards 100 percent renewable energy generation and exports by 2030.

Tens of thousands of adults joined the students, including wharfies whose walk off is the first known instance of industrial action to support climate "strikes" that have been held periodically since earlier this year.

The strike comes three days before world leaders meet in New York for the United Nations Emergency Climate Summit.

Scott Morrison will not attend the UN summit despite being in New York at the same time meeting with Donald Trump.

Universities have confirmed they would not penalise students for attending the rallies, while the Uniting Church synod for NSW and the ACT have backed their students to attend the demonstrations.

But Catholic and Anglican church-run schools say their students should remain in class, as do NSW public schools.

Acting Prime Minister Michael McCormack labelled the protests "a disruption" and said they should be held on weekends not school or regular work days.

"I think these sorts of rallies should be held on a weekend where it doesn't actually disrupt business, it doesn't disrupt schools, it doesn't disrupt universities," Mr McCormack told reporters in Melbourne.

He said students would learn more at school than at a protest rally.

Mr McCormack said the government was taking action to cut emissions and boost the use of renewable energy.

The Swedish teen climate activist who inspired school students around the world to rally, Greta Thunberg, sent out a tweet early this morning wishing luck to those striking in our region today. 

NEW SOUTH WALES

The Domain in Sydney, which has a capacity for 80,000 people, has been filled by thousands of protesters brandishing signs and cheering on speakers, who are addressing the crowd.

Earlier, many had to queue up in order to take part in the march through the Sydney CBD.

Police have confirmed that at least 50,000 people attended the Sydney rally.

Road closures remain in effect for Macquarie Street and for College Street between Macquarie Street and Park Street, while earlier closures on Elizabeth Street have been lifted.

Daniel, 15, from Fort Street High School in Sydney, said young people "are demanding more than they're being offered" from their leaders.

"Seeing how many young people are coming out, I think the current politicians we've got might not stay in power for so long anymore, with a new voting base coming in," he told AAP.

Bridget, 12, from Chevalier College in the NSW Southern Highlands, had a message for the country's politicians: "Don't be a fossil fool".

"I'm concerned about this because I kind of want a future," she said.

"They didn't do anything when they were kids so they left it all up to us to fix."

In Albury, strikers have targeted the federal environment minister Sussan Ley, staging a "die in" outside her electorate office.

Ralliers were chanting: "Sussan, Sussan please stop snoozing, Climate change is winning and you are losing".

The NSW Opposition Leader Jodi McKay has released a statement in support of the "passionate and idealistic" young students, commending them for "sending a message" to politicians.

QUEENSLAND

In Brisbane, thousands of people have flocked to Queens Gardens with the crowd spilling over onto the streets.

Lucy McDougall, from Mountain Creek State High School on the Sunshine Coast, should have been sitting a exam on Friday.

"I should be sitting in a chemistry exam today, and it's a significant one. Of course I'm concerned about missing that," the 16-year-old told AAP.

"But this is more important.This is a crisis and it's our future at risk.

She had a pointed message for Prime Minister Scott Morrison.

"He's going to die sooner than we are. This is our future. Start making choices that benefit us."

Large rallies are also taking place outside of the major cities. In Cairns, 1500 people are estimated to have turned out in a town of 150,000 people, where anger against the Adani coalmine remains fierce.

VICTORIA

Treasury Gardens in Melbourne was awash with young people this afternoon, with students making speeches on a milk crate podium.

The crowd in the Victorian capital looked set to exceed that seen in Sydney, with crowd estimates coming in as high as 100,000 people.

Meanwhile, thousands joined the march down Yarra Street in Geelong, chanting "What do we want? Climate action! When do we want it? Now!"

A number of students made emotional pleas in speeches outside Geelong City Hall.