In Queensland, which faces perhaps the greatest challenges for rehabilitation as the heart of Australian coalmining, the state government has more than quadrupled the bonds it has held since the height of the mining boom.

It now holds more than $7bn in financial assurance from mining, gas and oil companies, compared with $1.45bn in 2008.

The Queensland environment minister, Steven Miles, says when he took office in 2015, he was “shocked ... with just the sheer number of times” the department came to him to advise a miner had gone into liquidation, leaving behind as little as a 10th of what was needed for site rehabilitation.

“With Texas Silver, it was $2m when we needed $10m. With Linc Energy it was $3m when we need at least $30m. And they’re just the high-profile ones that have been in the media,” Miles tells Guardian Australia.

“This has literally happened over and over again. Until I was environment minister I believed – and I think the community believed – that this was all in hand and that there was always a bond in place that provided sufficient funds.

“All we’ve done is tighten that up to make good on what I think most people always believed was the case.”

Don't think this would have happened if Campbell Newman's LNP government had been re-elected. Queenslanders can feel relieved that they are now pulling back some of the enormous remediation costs that would otherwise have been almost entirely left to Queensland taxpayers.

But it's still not nearly enough:

But some experts, including University of Queensland researcher Peter Erskine, say what the state holds still falls billions short of what is needed.

Supporting Erskine’s view is a Queensland auditor general’s report from 2013. Even though the state had lifted its holdings to almost $5bn in 2013, the report warned that Queensland was still exposed where “sites remain with insufficient financial assurance”.