Bushfire survivors are challenging the expansion of the Narrabri coal mine in NSW arguing it negates commitments towards net-zero emissions.
Grassroots group Bushfire Survivors for Climate Action is taking an appeal to the NSW Land and Environment Court.
Whitehaven's application to expand its Narrabri coal mine was approved by the Independent Planning Commission in April.
Originally slated to operate until 2031, Whitehaven was granted an extension to 2044 to extract a further 82 million tonnes of coal.
The commission said the project on the state's northwest slopes fulfilled an "appropriate balance between relevant environmental, economic and social considerations".
The underground mine has been operating since 2011 and accounted for two to three per cent of the state's saleable production of thermal coal in 2019/20.
Whitehaven maintains the 13-year extension granted in April would provide the state with $600 million in economic benefits and keep 500 local jobs alive for decades.
The mining firm said it would "reduce CO2 (carbon dioxide) emissions at the mine over time".
But Fiona Lee, a member of the climate action group who lost her home to a bushfire in 2019, said the commission's approval of the coal mine thwarts efforts to seriously reverse the withering effects of climate change
"The burning of coal, gas and oil worsens the impacts of climate change, and we are already seeing bushfires and other extreme weather increase in frequency and intensity because of climate change," Ms Lee said.
"Approving new mines is adding to the problem and making the solution and emissions reduction targets even harder to achieve."
The advocacy group, represented by the Environmental Defenders Office (EDO), will argue that it is legally unreasonable for the NSW government to approve the mine because of pollution concerns that go against the public interest.
EDO Director of Legal Strategy Elaine Johnson said the commission "has a duty to make legally reasonable, rational planning decisions in the public interest".
"There is a huge body of scientific evidence that we must leave coal and gas in the ground to maintain a liveable planet. Approving more coal mines flies in the face of all the evidence."
