More than 70 people have been charged over climate change protests that caused major traffic disruptions in Brisbane's CBD.

Key points: Hundreds of protesters blocked traffic and caused extensive delays in Brisbane's CBD

Hundreds of protesters blocked traffic and caused extensive delays in Brisbane's CBD Dozens of police were on hand and there were more than 70 people arrested

Dozens of police were on hand and there were more than 70 people arrested The protest follows several others staged over the past few months

A heavy contingent of police, including mounted officers, were on the scene from this morning as hundreds of protesters converged on William Street and other areas of the city, with some activists sitting on roadways.

Police arrested 15 men and 12 women aged between 19 and 65 just before 8:30am for offences including contravene direction, obstruct traffic, obstruct police, and breach of peace.

Officers have since arrested many more protesters for similar offences in the CBD.

Police said they expected the disruptions to continue until 9:00pm as smaller groups broke away from the main crowd of activists.

Several activists who were blocking traffic were forcibly dragged from the road by police.

"We declare it our duty to act on behalf of our children … we declare ourselves in rebellion against our government," one protester told the crowd.

Translink has extra staff on to deal with disruptions as protesters march through CBD roads. ( ABC News: Dan Smith )

The main protest area was cleared out about 2:00pm and hundreds of protesters marched down from 1 William Street to Reddacliff Place, outside the city library.

Superintendent Chris Stream said some protesters were arrested for offences including public nuisance, disobeying lawful direction and also disrupting police.

"It is some time in the Brisbane city area since we've seen this amount of arrests," he said.

'We will do everything we possibly can to clear intersections and to enable at least limited traffic flow."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 58 seconds 58 s Extinction Rebellion protester arrested after blocking lanes in Brisbane CBD

He said police had been "generally happy" with the behaviour of protesters.

"What we are pleased to see is that the larger amount of police interactions today have not involved violence," he said.

"The only information I have in relation to a person being tackled to the ground was where a police officer was attempting to affect an arrest at the intersection of George and Elizabeth Street.

"A member of the public intervened as one of the protesters fled that area and tackled the protester to the ground."

Climate protesters also staged sit-ins along the road as they marched to 1 William Street. ( ABC News )

'Government is not representing the people'

Extinction Rebellion spokesperson Tom Howell told the ABC it was a citizen's duty to rebel.

"We cannot be ignored," he said.

"People are uncomfortable with disrupting other people's lives, but it is the best option we have left to get people talking about the climate emergency, to get the Government responding to it and to kind of make the economy pay attention to it, because if people can't go to work then the economy can suffer.

"Every other form of dissidence has failed.

"We've had our petitions, we've had marches, the Government is not representing the people."

Police made dozens of arrests when Extinction Rebellion protesters blocked traffic in the Brisbane CBD. ( ABC News: Dan Smith )

'You should be ashamed of yourselves'

Brisbane Lord Mayor Adrian Schrinner was heckled and interrupted by the activists when he tried to hold a press conference in the city this morning.

"I think you should be ashamed of yourselves," the Lord Mayor told members of Extinction Rebellion.

The protesters repeatedly shouted "shame on you" over the top of him, before the press conference was moved inside.

"The Lord Mayor has run away from citizens who care about climate change," former Greens lord mayoral candidate Ben Pennings told the media.

Brisbane's Lord Mayor Adrian Schrinner was heckled while trying to make a statement outside City Hall. ( ABC News: Dan Smith )

Translink's Matt Longland said the transport service had additional staff rostered on to manage disruptions to bus services.

"By all accounts, it will be larger and more disruptive than what we've seen in the past couple of weeks.

"We'll have additional people in the network coordination centre and also additional people on the ground that we can deploy into any areas where we're facing any issues.

"We'll need to obviously work closely with the Queensland Police Service about how the protesters are being managed and how we can keep vehicles — particularly bus services moving through the city efficiently."

Protesters sat on Margaret Street and blocked traffic. ( ABC News: Dan Smith )

Today's protest follows other climate change protests that disrupted Brisbane city traffic over the last two months.

In July, members of Extinction Rebellion stopped and started traffic every 10 minutes during peak hour.

On another occasion, nine protesters were arrested after they glued themselves to the road.

In June, Extinction Rebellion blocked part of Brisbane's Victoria Bridge, before they locked themselves together inside a canoe at South Brisbane.