A leading Australian disease expert says prompt action on climate change is paramount to our survival on earth.

Epidemiologist Tony McMichael has conducted a historical study that suggests natural climate change over thousands of years has destabilised civilisations via food shortages, disease and unrest.

"We haven't really grasped the fact that a change in climate presents a quite fundamental threat to the foundations of population health," Professor McMichael, from the Australian National University, said.

"These things have happened before in response to fairly modest changes to climate.

"Let's be aware that we really must take early action if we are going to maintain this planet as a liveable habitat for humans."