The government released an unclassified 116-page version of the defence strategic review on Monday, which warned climate change was a national security threat and might "significantly increase" risk of conflict in the region.
The review found the increasing number of major climate events risked overwhelming the government's capacity to respond effectively, and detracted from "Defence's primary objective of defending Australia".
"Climate events already place concurrency pressures on the ADF and this has negatively affected force preparedness, readiness and combat effectiveness," the report said.
The defence force has increasingly been called on by governments to supply personnel and capabilities as part of the disaster recovery response, as Australia has been hit with repeated extreme flooding and bushfires.
"Defence is not structured or appropriately equipped to act as a domestic disaster recovery agency concurrently with its core function, in any sustainable way," the review found.
Prime Minister Anthony Albanese said the nation needed to consider how it deals with natural disasters in the long term.
"The review indicates that there's a need to consider the broader issues," he told reporters.
Asked if the government would create a federal natural disaster agency to ensure the defence force was only used as a last resort, Mr Albanese indicated there would be a further announcement to come.
"We've got a pretty big announcement for today, I think that this will do for today frankly," said the prime minister, who will meet with premiers in Brisbane on Friday.
The review found the Commonwealth, in partnership with state and local governments, must have plans and resources in place to manage all but the most extreme domestic disaster operations.
"Defence must be the force of last resort for domestic aid to the civil community," the report said.
"This is critical given the urgent geostrategic risks that the nation faces and the need for the ADF to be in a position to respond to regional contingencies."
It warned climate change could lead to mass migration in the region, increased demand for peacekeeping and enforcement, and war.
In a statement, the Australian Security Leaders Climate Group said climate change needed to be included in review of the country's security posture.
Former defence force chief Admiral Chris Barrie, who is part of the group, said the region will face more threats, with the security landscape to be "far different from that which exists today".
"New initiatives for stronger regional cooperation in the face of this greatest threat to the human future are urgently needed," he said.
19°C