Australian coalmining has become a ''rogue industry'' and most of the coal slated for export must stay in the ground if the nation is to tackle climate change, according to prominent US environmentalist Bill McKibben.
Many coal projects, and coal infrastructure projects in Queensland, are expected to run for decades, and are only now gaining development approval.
But the federal government has pledged to reduce Australia's greenhouse output by 80 per cent by the middle of the century, putting it on a collision course with the resources expansion.
''If the world ever takes climate change seriously, that coal simply has to stay in the ground,'' Mr McKibben said. ''There's no physical way to burn it, or Canada's tar sands, or Venezuela's shale oil, and not go over the red line that almost all governments, including Australia's, have drawn at two degrees.''
Australian-mined coal burned overseas generates about 711 million tonnes of carbon dioxide a year, but when new mines are taken into account, that total will be up to 1431 million tonnes in 2020, and 1738 million tonnes in 2025.
Mr McKibben, the author of the first mainstream book about global warming, The End of Nature, will visit Australia in June to galvanise local campaigns for action against climate change. He is travelling to Australia with 350.org, the group he helped found in 2008.
''I think that, at this point, the fossil fuel industry is a rogue industry,'' he said. ''It wants to burn five times the carbon that the most conservative governments on Earth say is safe. They're not outlaw against the laws of the state … but they're outlaw against the laws of physics. If they carry out their business plans, the planet tanks.''
The independent Climate Change Authority is finalising an issues paper as part of its first review of Australia carbon targets and emissions trajectory. That review will examine carbon cuts to 2020 and the best pathways to achieve them. Draft recommendations are due in October, after the federal election.
"Emission reductions don't end in 2020," Climate Institute deputy chief executive Erwin Jackson said. "We're going to have to keep reducing them."
The authority said the review would recommend caps up to 2020 and also seek input on how much guidance it should provide the government on emissions reduction efforts beyond this decade.
The government and the Coalition both have targets to cut carbon emissions by at least 5 per cent on 2000 levels by 2020. The Coalition plans to set post-2020 emission targets in 2015 and has said it will scrap the Climate Change Authority if it wins office.
"We have always stated that the work of the Climate Change Authority should be done by the department, as was the case prior to the carbon tax bureaucracies that have been created,'' Coalition climate spokesman Greg Hunt said.