A group of 17 ex-defence and security leaders have penned an open letter attacking the Morrison government and calling for the dangers of climate change to be thrust to the top of the federal election agenda.

The letter from the Australian Security Leaders Climate Group comes as a new survey finds just a third of Australians believe the federal government has done enough to prepare and respond to natural disasters.

The group's statement also follows an extraordinary rebuke of the government from UN Secretary-General Antonio Guterres, who singled out Australia as a "holdout" in the push among wealthy nations to slash emissions this decade.

The Coalition brushed off the criticism as Energy and Emissions Reduction Minister Angus Taylor announced next week's federal budget would include an extra $50 million to support seven gas projects, as well as carbon capture and storage infrastructure.

Mr Taylor said the projects were needed to avoid the types of supply shortages experienced in Europe.

But critics say Australia doesn't have a gas supply problem and the announcement is a "cynical political move which lacked logic".

The government's policies for tackling global warming and preparing for climate change-fuelled natural disasters came under fresh scrutiny during the flood emergency in southeast Queensland and northern NSW earlier this month.

A group of ex-fire and emergency service leaders accused the government of "fumbling" the response and failing to heed the lessons from the Black Summer bushfires.

Now, the group of ex-defence leaders have launched their own pre-election intervention.

In the open letter, the group described climate change as the "greatest threat to the future and security of Australians".

But when it came to responding to the risk, former chief of the defence force Chris Barrie said Australia was "missing in action".

"The first duty of government is the safety and protection of the people, but Australia has failed when it comes to climate change threats," the open letter read.

"Australia currently has no credible climate policy, leaving our nation unprepared for increasingly harsh impacts.

"We call upon all those offering themselves as political leaders in this election year to make climate change a primary focus and commit to mobilising the resources necessary to address this clear and present danger."

The groups describes the goal of net zero emissions by 2050 as wholly inadequate and said carbon neutrality must be reached as close to 2030 as possible.

The letter urges the Coalition to join Labor in pledging to undertake a national climate risk assessment if it wins the federal election set for May.

John Blaxland, a former army officer and now Australian National University professor, said unlike the US and UK, the Australian government had not "assessed or understood" the risks posed by climate change.

"As a result, we are ill-prepared for the challenges we are already facing, we are not playing our part as a strategic defence ally and we are failing in our responsibilities as a global citizen," Professor Blaxland said.

Meanwhile, just 37 per cent of 1001 respondents to an survey from progressive thinktank The Australia Institute believed the federal government had done enough to prepare and respond to extreme weather events such as bushfires and floods.

More than 70 per cent wanted the Commonwealth to conduct a climate risk assessment.