Increased land clearing, particularly in Queensland, could wipe out gains made by the Federal Government's emission reduction scheme, new figures show.

A report commissioned by The Wilderness Society said, at existing tree-clearing rates, the emissions reduction fund could be exhausted by 2018 — two years before the 2020, 5 per cent emissions reduction target is achieved.

The report looked at the rates of clearing in various states and projected the potential impact on the Federal Government's emissions reduction scheme, taking into account discrepancies between federal and state figures.

Land service company CO2 Australia, one of the providers being paid to roll out the Australian Government's 20 Million Trees program, compiled the report.

The Wilderness Society said the Federal Government had so far spent about $670 million on 51 million tonnes of carbon abatement for tree clearing.

"Queensland alone will have negated that spending in just 18 months of clearing," national campaigns director Lyndon Schneiders said.

"At the current carbon price, tree-clearing emissions could cost up to $720 million annually. That could negate the remaining $1.35 billion left in the emissions reduction fund budget in two years.

"Clearly if we're in a situation where on one hand the Federal Government is buying tree-clearing permits to stop emissions, and on the other hand the state governments are issuing more and more permits, and creating more clearing, there's a problem."

Federal Government denies target will be missed

A spokesman for federal Environment Minister Greg Hunt argued the Government's emissions projections, which take into account the Queensland Government's land-clearing practice, showed Australia was on track to beat its 2020 target by 28 million tonnes.

In a statement, he said the accounting system was endorsed by the United Nations and was considered world's best practice.

He said the Queensland data was not designed to measure emissions from land clearing at an aggregate basis.

However, Mr Schnieders said broadscale land clearing generated significant greenhouse gas emissions

"The figures don't lie," he said. "The figures from Queensland are telling us there's been a massive upscale in those clearing figures in the last couple of years.

"But the Federal Government isn't counting that and their figures are flawed as a result."

In 2013-14 about 296,000 hectares of Queensland bushland was destroyed.

The Queensland Government is in the process of overhauling changes to tree-clearing laws introduced by the former Newman government.