Gina Rinehart’s Alpha mine challenge

The GVK Hancock Alpha coal project in the the Galilee basin in central Queensland. Photograph: Andrew Quilty/PR Image

Activists are arguing their case in the Queensland supreme court in a bid to overturn the government’s approval of the Galilee basin coal mine

Conservationists challenging Gina Rinehart’s mining ambitions in Queenslandhope to force the state government to consider carbon emissions from exported coal when assessing projects.

The Coast and Country group was in the supreme court in Brisbane on Wednesday attempting to overturn the Queensland environment department’s approval of the Alpha mine, which it argues did not properly take into account the impact of emissions.

The group is also challenging a decision by the land court last year that the mine could be approved subject to conditions about its use of groundwater. It argues that the court also did not consider climate change impacts of the “transport and use of the exported coal” and that the proposal should be rejected outright.

The Alpha mine, a joint venture between Rinehart’s Hancock Coal and Indian conglomerate GVK, would produce an estimated 60m tonnes a year of CO2 – as much as 11% of Australia’s total emissions, according to the conservationists.

The project is one of nine proposed mines in central Queensland’s Galilee basin, along with Adani’s Carmichael mine, the subject of a separate federal court challenge and legal action by Coast and Country in the land court.

Coast and Country spokesman Derec Davies said the impact of the mine, which would ship its coal through Great Barrier Reef waters via Adani’s controversial proposed Abbot Point port, would be “monumental”.

Jo Bragg, the chief executive of the Queensland environmental defenders office, which is acting for Coast and Country, said outside court a ruling that carbon emissions from exported coal were a necessary factor in environmental approvals would be a watershed for mining assessments.

Bragg said the state environment department did not consider carbon emissions for exported coal when issuing environmental authorities, or approvals, for mines.

“They certainly should be taking into account greenhouse gas emissions from these big mining projects when the coal is exported and burnt overseas,” she said.

“We say that’s the law under the Queensland Environmental Protection Act but we’re seeking to have that point clarified by the supreme court.

“We say that the law is clear, that damaging greenhouse gas emissions form Aussie coal burnt overseas is relevant to decisions in Queensland.”

Bragg said the former environment minister, Andrew Powell, “rushed ahead and approved the project” after Coast and Country had launched its supreme court challenge to the “legally flawed” land court ruling.

That approval was therefore invalid, she said, adding the company was yet to obtain a mining lease for Alpha.

GVK Hancock Coal said in a statement that anti-mining protest groups with “ideological objections to our country’s second largest export industry” were using the courts to “delay thousands of jobs for Queensland”.

“What we are witnessing is court decisions being taken to court for additional court decisions,” it said. “This challenge does not involve landholders and our projects will not impact the Great Artesian Basin.”

The company said it was a bid to hold up a project that would create 7,000 jobs in construction and another 4,000 direct operational jobs for more than 30 years.

GVK Hancock said the land court ruled that all objections about climate change impacts and greenhouse gas emissions from the project were addressed by the company’s environmental assessments.

It said it had presented two of the three landholders involved in the land court challenge with “reasonable make-good agreements” which held the company legally liable “in the unlikely event of unduly impacting their groundwater resources”.

The landholders argued the extraction of 176bn litres of water over the life of the mine would lower the water table by five metres and threaten their livelihoods.

One of those landholders, Jericho grazier Bruce Currie, said he was “no anti-coal mining activist” but supported the current legal challenge to the mine. He said GVK Hancock had presented several draft agreements but “no satisfactory agreement had been signed”.

The third landholder in the land court case had repeatedly refused to meet the company, GVK Hancock said.