The School Strike 4 Climate Australia action included major rallies in capital cities as well as smaller protests by other groups targeting federal MPs.

Organisers said about 3000 people took part in Brisbane about 1500 in Adelaide, 1000 in Perth, 650 in Darwin and more than 500 in Hobart.

They said taking into account smaller regional events, about 10,000 were involved across the country.

With two weeks to go before the United Nations Climate Change Conference in Scotland, 15-year-old Adelaide student Anjali Beames said the federal government had shown "time and again that they do not care about the future of young Australians".

"This government is failing young people and future generations," she said.

"Today we are taking our protest directly to decision-makers to show them again that the climate crisis is a crisis, and that there are repercussions to not listening."

The Tamworth Parents and Friends for Climate Action group read stories about saving the planet outside the regional NSW electorate office of Deputy Prime Minister Barnaby Joyce.

"Our region is ideally placed to reap huge benefits in a renewable economy. Our solar and wind resources are amongst the best in the country," parent Tessa Rainbird said.

"Yet Barnaby Joyce often paints a picture that regional communities aren't concerned about climate change, or are reluctant to transition away from a fossil fuel economy.

"We are here to tell him that is simply not the case. We understand the science, we are very worried, and we want to move with the rest of the world on this issue."

In Tasmania, members of a new parents for climate action group joined students and other concerned residents on the Burnie foreshore.

Local mother Hannah said the federal government could not suggest it was taking climate change seriously while it continued to approve new coal mines.

"Australia is fast becoming an international pariah and an embarrassment on the global stage, and our kids are missing out on the jobs of the future," she said.

At the Glasgow UN conference (COP26), countries are being asked to come forward with ambitious 2030 emissions reduction targets that align with reaching net zero by 2050.

They are being urged to accelerate the phase-out of coal, curtail deforestation, speed up the switch to electric vehicles and encourage investment in renewable energy.

The Australian government has so far committed to reducing emissions by between 26 and 28 per cent by 2030.

But it is also working on a plan on how to reach net zero by 2050.

Australian Associated Press