AUSTRALIA faces more frequent and more catastrophic natural disasters as the climate changes, but government agencies are hard-pressed to respond, a new study warns.

The disasters could occur simultaneously and in regions that have never before experienced such events, the Australian Strategic Policy Institute (ASPI) says.

In a paper released on Monday, the institute’s director of research Anthony Bergin and director of the Australian Homeland Security Research Centre Athol Yates said climate change was happening now and vulnerability to natural disasters was increasing.

“Climate change has the potential to increase the likelihood of catastrophic disasters in Australia,” they said.

The “devastating” economic, social and environmental consequences could exceed the capability of state disaster management arrangements.

As a result of climate change, disasters were likely to become larger, more complex, occur simultaneously and in regions that had either not experienced the natural hazard previously or at the same intensity or frequency.

Climate change needed to be acknowledged by security planners as a significant homeland security threat, Dr Bergin and Mr Yates said.

Emergency management was primarily a matter for states and territories, but they believed there was a strong case for the commonwealth to take a stronger leadership role, as it had done with terrorism.

There should be significant investment now on the basis that a dollar spent in mitigation saves $2-$10 in avoided or reduced disaster response and recovery costs, they said.

“We should invest today for a safer tomorrow by making sure we have a resilient infrastructure to cope and deal with the consequences,” they said, adding such action would ultimately make Australians safer from all hazards.

Prime Minister Kevin Rudd, in a national security statement delivered last December, warned that climate change represented a fundamental and long-term national security challenge.

He identified unregulated population movement, declining food production, reductions in arable land and violent weather events as emerging threats.