The paper, released by two Australian National University experts, says the nation's emissions will decline by as much as three to four per cent between 2020 and 2022.

This is due to the influx of renewable energy projects poised to become part of the electricity system.

The researchers said Australia can easily meet its 2030 carbon emissions target by replacing coal-fired power stations with renewable energy sources.

Under the Paris agreement Australia and other signatories pledged to reduce emissions by 26 to 28 per cent on 2005 levels by 2030.

But the paper also warned that beyond 2022, emissions "may rise again" unless there's support to allow the "continued rapid deployment" of solar and wind.

"This analysis is ignorant and misleading - investment in renewable energy has already slowed," Clean Energy Council CEO Kane Thornton tweeted.

The dip in investment this year has led industry to renew its calls for a long-term national energy policy, and another renewable energy target.

Responding to the paper, Energy Minister Angus Taylor pointed to recent figures from the Clean Energy Regulator showing there's $25 billion of new wind and solar due for 2018 to 2020.

"Unprecedented growth in generation from wind and solar reinforces the need for more investment in storage and transmission," he said.

The minister's focus is on keeping coal-fired power stations in the market for as long as possible, or replacing them with like-for-like capacity.

Mr Taylor has also spearheaded an underwriting new generation investments plan, which includes 12 shortlisted projects - mainly gas and hydro.

The minister's office did not respond to AAP on how these two factors would impact the emissions projections of the paper.

Meanwhile, the Climate Change Authority revealed its constraints to a late night time-slot of Senate estimates hearing earlier this week.

The authority's budget will remain at about $1.5 million a year for the next four years, keeping the staffing level at nine people.

"With the level of funding and the smaller number of staff that we have, there's a limit to what we can do," head Wendy Craik said, referring to the authority's smaller output over recent years.

The Climate Change Authority hasn't been asked to do any work on emissions reduction targets after 2030.

It also hasn't been asked to provide the government with advice on a 2050 strategy, which Prime Minister Scott Morrison signed up to at the Pacific Islands Forum in Tuvalu.

Australian Associated Press