Exclusive: Conservation group argues Greg Hunt did not take into account the impact on the reef of greenhouse gases emitted when burning coal from Queensland’s Carmichael mine

The federal court is being asked to overturn the environment minister, Greg Hunt’s approval of Indian company Adani’s $16.5bn Queensland coalmine because he did not take into account the impact on the Great Barrier Reef of the greenhouse gases emitted when the coal is burned.

Environment ministers usually consider only the emissions from greenhouse gases that are produced during the mining process, not the emissions produced when the coal is burned, and Adani was not required to consider emissions from the burning of the coal mined in its environmental impact statement.

But a test case lodged by the NSW Environmental Defenders Office (EDO) on behalf of the Mackay Conservation Group argues that the emissions from burning the estimated 60m tonnes a year of coal to be exported from Adani’s Carmichael mine are big enough to have an impact on global warming and therefore on the Great Barrier Reef.

“We will argue that the minister failed to consider the greenhouse gas emissions arising from the burning of coal mined from the project and the impact of those emissions on nationally protected matters, such as the Great Barrier Reef,” EDO NSW said.

Hunt was specifically required to take the impacts of the Carmichael mine on the reef into account when making his decision about the Carmichael mine last July.

The case is the third lodged by environmental and community groups against the Carmichael mine, as they ramp up a campaign to try to stop the development of the giant Galilee basin’s coal reserves.

The Queensland premier, Campbell Newman, has made the development of the Galilee basin a key state election issue, promising an unspecified sum to take a minority stake in the rail line necessary to bring Adani’s coal to port and to develop an onshore disposal site for dredge spoil from Adani’s coal port.

Newman and Adani say the mine will create 10,000 jobs and pour $22bn in royalties into the state’s coffers. An Adani spokesman said these figures came from a recent study from “a top-tier international accounting and advisory firm” which was not publicly available. He said they were conservative estimates.

The Labor opposition supports coal mining, but not the taxpayer subsidies being offered by the Coalition government.

The Carmichael mine’s environmental impact statement says it will produce over 200m tonnes of CO2 over the 60-year life of the mine from gases that escape during the mining process and from emissions created from mining and transporting the coal. But burning the 60m tonnes of coal exported from the mine each year would create 130m tonnes of carbon dioxide every year, equivalent to about one quarter of Australia’s total emissions.

It could be several months before there is a decision in the case. If the court found in favour of the Mackay Conservation Group the minister would be required to reconsider his approval of the project.

Coast and Country Association of Queensland, represented by EDO Qld, has taken separate legal action against the mine in the Queensland land court.

Greg Hunt, the federal environment minister, has hit out at activist group GetUp over a legal challenge targeting his handling of a plan to dump seabed sediment on to a sensitive wetlands area near the Great Barrier Reef.

The Alliance to Save Hinchinbrook, a Queensland conservation group, has launched court proceedings in Brisbane using funds donated from a GetUp campaign.

Hunt has yet to make a decision about the new plan to dispose of the sediment produced from the dredging for the new coal ports.

Hunt’s spokesman has been contacted for comment.