Eve Moss Ractliffe, a 14 year-old student and climate activist, wears a protective face mask with the words "Climate Action Now," while participating in a "School Strike 4 Climate" rally in Sydney, Australia, May 21, 2021.
Eve Moss Ractliffe, a 14 year-old student and climate activist, wears a protective face mask with the words "Climate Action Now," while participating in a "School Strike 4 Climate" rally in Sydney, Australia, May 21, 2021. Reuters / LOREN ELLIOTT

Australia's Greens party on Wednesday threw its support behind the government's climate change legislation, clearing the way for a bill enshrining a pledge to cut carbon emissions by 43% by 2030, but said it would oppose new fossil fuel projects.

Australian politicians have been battling over climate policy for more than a decade, ever since the Greens opposed a carbon policy proposed by a Labor government in 2009.

The defeat of that policy started a string of U-turns on climate policy that led to the dumping of four prime ministers by their parties and was a major factor in the defeat of a conservative government in the last election in May.

"Labor said passing this bill will end the climate wars. The Greens will do our bit," Greens leader Adam Bandt said in a televised speech to the National Press Club in Canberra.

"But Labor is set to undo parliament's work by opening new coal and gas projects unless we stop them," he said.

The Greens party won a record number of seats in the May election, reflecting growing concern about climate change amid worsening bushfires and floods, and the government needs their support to get legislation through parliament.

The climate change bill will set into law Australia's pledge under the Paris accord to cut greenhouse gas emissions by 43% from 2005 levels by 2030.

The legislation is set to pass in the lower house, where it was introduced last week, as Labor has a majority there.

In the Senate, Labor needs the support of the 12 Greens senators and one other for the bill to pass, as Labor does not have a majority in the upper house and the opposition has vowed to veto the bill.

"It's now very clear that our legislation will pass the parliament," Climate Change and Energy Minister Chris Bowen told media after Bandt spoke.

The Greens have long called for a far more ambitious emissions reduction target for 2030, but Labor refused to raise the 43% target as it looked to shore up votes in May in coal-mining and gas-producing electorates.

However, the Greens negotiated changes in the bill including ensuring that the emissions target could not be cut.

"You can only end the climate wars by keeping coal and gas in the ground," Bandt said.