Electricity emissions have jumped since the repeal of the carbon tax, the Climate Council says.

The council cites new data by consultants Pitt & Sherry, showing carbon dioxide emissions from the electricity grid went up 6.4m tonnes in the last financial year since the tax was axed.

The increase of 4.3% has undone part of an 11% fall in emissions during the two years the tax was in place.

The federal government will soon outline Australia’s post-2020 targets, before the Paris conference in December.

“The news that emissions have gone up in Australia will do little to counter the impression that Australia is acting as a ‘free rider’ on the back of other countries’ efforts,” the Climate Council chief executive, Amanda McKenzie, said in a statement on Sunday.

The environment minister, Greg Hunt, has said the country’s future carbon targets will be credible.