The latest federal government carbon emissions inventory shows Australia has increased its emissions and has come under fire for allegedly vastly underestimating the amount of land clearing that has occurred, and its associated emissions.

The Quarterly Update of the National Greenhouse Gas Inventory Report, which counts emissions in Australia up to September 2015,says greenhouse gas emissions from land clearing have fallen to record lows.

But Guardian Australia reported last month that a report commissioned by the Wilderness Society showed a land clearing surge in Queensland since 2012 has been so big that it would create emissions roughly equal to those saved by the federal government’s emissions reduction scheme, where they paid other farmers more than $670m to stop cutting down trees.

The amount the Queensland government said was cleared in that state alone was almost twice what the federal government said was cleared nationwide in 2014. Queensland reported that almost 300,000ha were cleared in the 2013-14 financial year, while the federal government says less than 170,000ha were cleared nationwide.

Looking at the emissions arising from land clearing, the federal government’s report says there have been only 10.8m tonnes of C02 emitted in 2014 and 2015, and just slightly more in 2013. But the Queensland figures say that state alone produced 38m tonnes of CO2 from land clearing in 2015, up from 25m tonnes in 2013.

In response to those alleged discrepancies reported by Guardian Australia, the Department of Environment added a new explanatory section to the quarterly report.

It raised seven differences in the ways Queensland and the federal government measure land clearing, and concluded that “it is not appropriate to compare the two data sets directly without adjusting the data for these differences”.

But the report does not explain how those differences could explain such a vastly contrasting result.

“It defies logic. This is a major discrepancy that can’t be brushed off with the same inadequate explanations used so far,” the Wilderness Society’s climate campaign manager, Glenn Walker, said.

“The government “is either using very creative arithmetic or expects us to believe that the rest of Australia has planted enough trees to suck up the equivalent of about 20 million tonnes of carbon dioxide from the atmosphere,” he said. “That’s more than the emissions from Australia’s dirtiest coal power station Hazelwood.”

Senator Larissa Waters, the Australian Greens climate change spokeswoman, said: “The Turnbull government is using dodgy numbers so it can allow its big fossil fuel donors to keep polluting while claiming to be meeting its woefully inadequate reduction targets set by Tony Abbott.”

Even with the contested drops in emissions from land clearing, the report shows that emissions have risen.

“In a sign of just how dodgy the accounting behind their climate targets is, the government is claiming to be meeting its 2020 target even though climate pollution is up,” Waters said.

The report does not include any projections to 2020 or beyond, and so is unable to back up the government’s claims that Australia’s emissions peaked in 2005. And the government’s own projections from 2015 found they would be much higher by 2035.

“We continue to see emissions steadily growing all the way to 2030, despite current policy,” said Hugh Grossman, the chief executive of the environmental consulting company RepuTex.

“That’s cause for concern, in that current policy – even the [Emissions Reduction Fund] – is not curbing our national emissions growth. If the argument is about how much emissions are growing, we’re a long way from seeing emissions reductions.”

A spokeswoman for Hunt said: “The emissions projections already fully take into account the Queensland government’s land clearing laws and practice.”

“The advice from the Department of the Environment is clear, categorical and absolute,” she said, alleging that the Wilderness Society “wilfully misinterpreted data”.

She said Australia’s accounting system was subject to external scrutiny by a panel of international experts appointed by the UN framework convention on climate change.

“Is the Wilderness Society now questioning the authority of the UNFCCC?” she asked.