A drop in emissions during the second year of the carbon tax was due to below trend economic growth, according to Federal Finance Minister Mathias Cormann.

A report released by the Environment Department on Tuesday showed Australia's estimated greenhouse gas emissions fell by 1.4 per cent in 2013-14, compared to the previous financial year.

The carbon tax came into effect from 1 July 2012 under the previous Labor government until 1 July 2014, when it was repealed by the current Abbott Government.

Speaking in Perth on Saturday, Mr Cormann said Australia's emissions had reduced due to below trend economic growth.

"Emissions were falling before the carbon tax came into effect and we were meeting our Kyoto targets well before the carbon tax came into effect," he said.

"Over the past two years the economy has grown below trend, and below trend growth means that emissions will be lower than they otherwise would have been."

Opposition spokesman for climate change Mark Butler said the report proved Labor's policies were working.

"The National Greenhouse Gas Inventory - dropped by the Government in the lead up to Christmas in an effort to bury the report - showed that the emissions count for the overall year of Labor's climate policies reduced by 1.4 per cent," he said.

"That compares to a decline in emissions of 0.8 per cent for the previous 12 months, which shows that Labor policies to reduce emissions were working - to say otherwise is laughable.

"Tony Abbott has dismantled all this positive action to address climate change, choosing instead to use taxpayers money to pay big polluters to pollute."

The new data from Australia's National Greenhouse Gas Inventory showed a decline in electricity emissions in 2013-14, which, the report stated, reflected lower electricity demand and changes in the generation mix.

The report said emissions from transport, industrial processes and agriculture declined during the year, but they were partially offset by increases in the fugitive emissions and stationary energy sectors.

The data also showed emissions increased by 0.4 per cent in the June quarter of 2014, or 0.2% seasonally adjusted.

Mr Cormann said he was confident in the Federal Government's climate change plan.

"The truth is that our Direct Action policy, which was legislated by the Parliament, will ensure we achieve our emissions reductions targets for the future," he said.