The Governor-General has signed off on a royal commission into this summer's devastating bushfires, with a specific focus on preparedness for future bushfire seasons.

Key points: A leading environmental lawyer and a former Federal Court Judge will join the bushfires royal commission

A leading environmental lawyer and a former Federal Court Judge will join the bushfires royal commission The royal commission will consider how governments can better prepare and respond to bushfires

The royal commission will consider how governments can better prepare and respond to bushfires The Prime Minister wants a final report handed to the Government by the end of August

Two more commissioners, former Federal Court judge Annabelle Bennett and leading environmental lawyer Andrew Macintosh, will join former Australian Defence Force (ADF) chief Mark Binskin.

The trio are due to deliver their findings to the Federal Government by the end of August.

More than 30 people died across the country during the disaster, and thousands of homes were destroyed.

The ABC revealed earlier this month that hazard reduction would form a key part of the inquiry, after Prime Minister Scott Morrison demanded an investigation into whether controlled burns and land clearing operations had been hampered across the country.

Climate change, and specifically its effect of creating longer, hotter and drier fire seasons, will also be considered by the royal commission.

"This royal commission accepts, it acknowledges, it understands the impact of climate change, more broadly, on the climatic conditions that Australia is living in," Mr Morrison said.

"What this royal commission is looking at are the practical things that must be done to keep Australians safer and safe in longer, hotter, drier summers."

Hazard reduction planning will be a significant focus of the royal commission. ( ABC News: Matthew Doran )

Assessing governments' responses to bushfires

The terms of reference cover a range of matters across Commonwealth, state, territory and local governments.

They include preparedness and recovery, natural disasters, hazard reduction, wildlife conservation, development approvals, and the debate over when the Federal Government can step in to offer assistance.

That latter point was highlighted as a concern for the PM during an interview with the ABC in January, when Mr Morrison argued the Commonwealth's hands were tied when responding to the unfolding emergency because it had to wait for formal requests for help from the states.

The commissioners will also investigate whether the findings of previous royal commissions and inquiries have ever been acted on.

Traditional land management techniques used by Indigenous Australians will form part of the inquiry.

Hundreds of homes, businesses and outbuildings in Mogo, on the NSW South Coast, were flattened by the Clyde Mountain fire on New Year's Eve.

Mogo business owner Theresa Matthews told the ABC she was concerned the commissioners wouldn't have enough time to complete their work within six months.

Theresa Matthews is concerned that the royal commission will have to report back to Government within months. ( ABC News: Adriane Reardon )

Fellow business owner Brian Aitchison echoed those sentiments and said he was unsure if the royal commission could finalise its findings by August 31.

He opened his business on December 13 but had been closed since New Year's Eve because of the fires. He reopened his business on Thursday.

But Mr Morrison insisted the commissioners had a reasonable timeframe to complete their final report.

"It's the same length of time that is being done for the state inquiries," he told reporters.

"It's important that we get this done quick because we need to ensure that we have advice coming back to us, particularly as we go into next season."

The Prime Minister said the three commissioners were well placed to investigate the broad range of issues.

"I have asked a former judge, a former chief of the defence forces, and a scientist, a professor who has experience in dealing with climate change adaptation — so these are experts who can shed a lot of light on this."

Air Chief Marshal Binskin finished his term as chief of the Defence Force in 2018, while Dr Bennett retired from the Federal Court bench in 2016.

She is now the chancellor of Bond University in Queensland.

Andrew Macintosh is a professor of law at the Australian National University and a member of the university's Climate Change Institute.

He is also a member of the panel currently reviewing the Environmental Protection and Biosecurity Conservation Act, and whether it is putting too much "green tape" in the way of projects across the country.