Australia's greenhouse gas emissions could return to 2005 levels by 2030 without new government action, contrary to the scenario modelled by the Finkel review, according to a new report by respected analyst Hugh Saddler.

Under Australia's Paris climate commitments, total emissions are to drop 26-28 per cent on 2005 by the end of the next decade, a pace the Chief Scientist Alan Finkel has modelled for the electricity sector in this review.

While the reductions since 2005 have achieved about half of the annual reductions needed to hit the 2030 goal of 430-442 million tonnes of carbon dioxide, they have come mostly from reduced land clearing in Queensland and NSW. Both states, though, are likely to see emissions rebound from 2013 lows as restrictions ease.

"In the absence of further policy action, Australia's total emissions will increase from the [2015 level] of 525.6 million tonnes of CO2-equivalent to between 571 and 616 million tonnes by 2030," Dr Saddler said in the first National Energy Emissions Audit report prepared for The Australia Institute.