A cyclone the size of Debbie could have catastrophic consequences on the Gold Coast, new modelling has shown, as climate change pushes cyclones further south and puts tens of billions of dollars worth of infrastructure at risk.

Actuaries, who predict and model scenarios for banks and insurers, have warned properties could become "uninsurable" as premiums rise to meet environmental challenges. Debbie devastated northern Queensland and swept floods into NSW which caused $1 billion in damage, forced 30,000 people to evacuate and took two lives.

Under modelling compiled by Deloitte's principal actuary Sharanjit Paddam and James Cook University, a shift in the cyclone-prone region of just three degrees would cause winds in excess of 260km/h to hit the Gold Coast and stretch as far as Brisbane, where many homes and towers do not meet cyclonic safety standards.

The "sting in the tail" of ex-Cyclone Debbie battered the Gold Coast this week with winds half as strong as those that hit Bowen and Proserpine, along with torrential downpours.