Thousands of people have marched through the streets across Australia as part of protests against Adani’s Queensland coal mine.

Rallies in Melbourne, Sydney, Brisbane and Cairns come a week after upwards of 15,000 school students demonstrated against government inaction on climate change.

It follows the announcement last month by Adani it would self-fund the controversial project after scaling back its size and scope.

The coal project is being downsized from a 60-million-tonnes a year, $16.5 billion mega-mine to a more manageable 10-to-15 million tonnes a year costing around $2 billion.

“No longer will we sit back and be lectured to by people who are outdated and out of touch,” Thomas Cullen told hundreds of protesters gathered in Brisbane on Saturday.

The 17-year-old was one of the thousands of students criticised by Prime Minister Scott Morrison for skipping school to stage national strikes calling for immediate action on climate change just over a week ago.

He travelled to Canberra this week for a sit in on the marble floors of parliament to confront Mr Morrison over the issue.

“We are preparing to show our leaders that we will not stand for their inaction,” he added.

“We will strike until our leaders shape up and act.”

All over Australia and the world, people are taking action and calling on the Australian government to put an end to the Adani mine once and for all. Follow all the events using #StopAdanihttps://t.co/dyQwwBEF0c

— 350 dot org (@350) December 8, 2018

April McCabe, 24, says there is a growing sense of urgency among university and high school students who want their governments to act on climate change.

The Queensland public health and global studies student says news that major works on Adani’s Carmichael mine in the state’s Galilee Basin are imminent has provoked more young people to push for change.

“It has been talked about but now people are taking action,” she said.

In Sydney, protesters carried an array of signs, such as those reading “Time for a COALonoscopy”, “There is no Planet B”, “I bet the dinosaurs thought they had time too” and “The climate is changing, why aren’t we?”.

Hey Hey! Ho Ho! Adani's mine has got to go! #fight4future #StopAdani pic.twitter.com/QYEXVWmUt6

— School Strike 4 Climate Australia (@StrikeClimate) December 8, 2018

Jean Hinchliffe, 14, said Australia’s leaders were displaying continued ignorance and had tried to disregard the student climate change protest she headed in Martin Place last Friday.

“This is something we’re not going to sit on the fence about and we’re going to keep fighting until the Labor party rule out Adani’s coal mine and all other new coal mines for good,” she said.

The vocal crowd then descended on the ALP’s headquarters, with “sit down” action planned outside deputy leader Tanya Plibersek’s office on Wednesday in the lead-up to the party’s national conference.

Adani Mining chief executive Lucas Dow last month said the Indian mining giant will self-fund the controversial project after it struggled to get external funds.

-AAP