Endangered koalas could lose more than 11,600 hectares of precious habitat if the environment minister approves a new generation of coal projects.
An analysis by climate and conservation groups details the cumulative impact of 23 new coal projects sitting on Tanya Plibersek's desk, and three others that soon will be.
If all are approved under federal environment laws, koalas will lose the equivalent of 41 Sydney CBDs worth of bushland.
That's a minimum, the groups say, with some coal companies yet to articulate how much habitat will be affected by their developments across Queensland and NSW.
The minister's office insists reforms are strengthening protections.
But the projected developments are predicted to pump about eight billion tonnes of pollution into the atmosphere over their life spans - more climate pollution than Australia has emitted over the past decade.
The Queensland Conservation Council is among the groups behind the analysis, which it states is based on coal producers' own figures.
Nature campaigner Natalie Frost says koalas are already under enormous threat from habitat loss and climate change, which is increasing the risk of disasters like the Black Summer bushfires.
One report estimated 60,000 koalas were affected by those fires - a major factor in the decision to up-list koalas in Queensland, NSW and the ACT from vulnerable to endangered.
"Minister Plibersek has pledged 'no new extinctions', but has failed to rule out allowing new coal mines to clear important koala habitat, despite the very real threat of koala extinction due to habitat destruction and climate change," Ms Frost says.
"She must reject these disastrous new koala-killing coal mines."
The analysis is also the work of the Lock the Gate Alliance and the NSW Nature Conservation Council, which say eastern Australia is already a global deforestation hotspot and can't take much more.
A spokesperson for the minister says the government's promised suite of environmental reforms will strengthen protections for nature, and ensure the cumulative impacts of development are taken into account.
The existing Environment Protection and Biodiversity Conservation Act, which is supposed to safeguard threatened species, is being rewritten after a scathing review found it was incapable of producing good outcomes.
The Labor government has come under heavy fire for delaying the rewrite of that act.
No time frame has been specified, and the minister has not committed to getting the job done before the next election.
