"Australia intends to take an 'emissions budget' approach to tracking progress towards 2030, meaning that emissions in every year from 2021 to 2030 are included in accounting against the target," a spokesperson said.

Details of Australia's commitment are laid out in its Intended Nationally Determined Contribution.

Sensitive timing

The distinction is not a small one. It means, for instance, that Australia couldn't maintain current level emissions until 2029 and then make a sudden, sharp reduction in the final year of the agreement.

The issue comes as Environment and Energy Minister Josh Frydenberg held a call with state and territory counterparts on Friday to discuss what could be the final design of the government's National Energy Guarantee (NEG).

“As the government has made clear before, legislation on the [NEG] will be taken to the Coalition Party Room should the COAG Energy Council agree to the Guarantee’s implementation at the August meeting," Mr Frydenberg said, without directly addressing Mr Kelly's issues with emissions goals.

The NEG aims to improve grid reliability as more renewables are added, while pushing prices lower and meeting Australia's Paris emissions goal.

'Completely different'

Mr Kelly told Fairfax Media that the total emissions budget - which largely precludes his plan of ramping up reductions closer to 2030 - was "completely different from what the [Coalition] party room had been led to understand".

"If that's what the Environment Department is saying, that is for sure contradictory to [my understanding] and [that of] many others in the party room" of the implications of the Paris goals, he said.

"It does make a very, very big difference," Mr Kelly said, saying that the issue "will have to be clarified".

Mr Kelly said he had also approached the parliamentary library service to have the department's statement checked for accuracy.

Loading

Mark Butler, Labor's climate spokesman, said the Turnbull government had "given up on reducing emissions and meeting our Paris commitments".

"Malcolm Turnbull and Josh Frydenberg continue to ignore their own department's data and instead kowtow to the hard right of the Coalition party room," Mr Butler said, adding that emissions would "continue to skyrocket" under the government.

"Delaying action in electricity, as proposed by Craig Kelly, means that in future years, much larger emission reductions are needed to recover ground relative to the government's linear reduction model," Alan Pears, an energy expert with RMIT University, said.

Others, though, pointed out that an emissions budget has been clear for years:

Other concerns

Loading

Mr Kelly said he also had concerns that the government's plan to cap emissions reductions in the electricity sector to 26 per cent from 2005 levels by 2030 would have big implications for other sectors of the economy that would be less capable of cutting emissions.

He noted transport emissions are projected to rise under a business-as-usual case from 80 million tonnes of CO2-e in 2005 to 110 million tonnes in 2030. A 26-28 per cent reduction would imply emissions from that sector dropped to about 60 million tonnes or less by 2030.

Taking "every single car off the road in 2030" would only deliver about 44 million tonnes of cuts, he said.

A similar problem exists in agriculture, "where about 90 per cent of emissions are animal farts", and would be difficult to reduce merely by changing the type of fodder cattle ate, he said.