“The February 28 flood was like nothing we have ever lived through before. Lismore is a flood city and flooding is part of our DNA,” she said. “When we prepared for that flood,we prepared for 12 metres. We would have bounced back from that quite well. But what we got was 14.4. And the scale and the devastation of that event was like nothing we have ever experienced.”

“I have spoken to people who have lived here for their whole lives,local builders,born and raised here and they say this was different,” Bird said. “This is different. We have to respond differently. We have to think differently,and we have to make different plans off the back of this.”

Climate Valuation considers properties to be effectively uninsurable - a point where insurance becomes unavailable or too expensive - when the annual cost of extreme weather related damage reaches 1 per cent of the replacement cost of the property. It presumes replacement cost to be $314,000,which it says is a conservative average.

It built a “climate risk engine” which combined data from local meteorological stations with information about the specific location,such as flood mapping and depths,elevation above sea level,tides and waves,soil type,and forest cover;and data on the assumed building at that address,such as age,construction materials and design.

Along with the 520,000 properties to become effectively uninsurable by 2030,a further one in 10 will reach the “medium risk” classification by 2030,with annual average damage costs equalling 0.2 per cent or more of the property replacement cost.

The Climate Council is calling on Australia to reduce its carbon emissions by 75 per cent by 2030,about three times the current level of commitment.

A spokeswoman for the Insurance Council of Australia said at present no area of Australia was uninsurable,although there were some locations with clear affordability and availability concerns.

“Insurance prices risk,and that means that for those in flood-prone or cyclone-prone locations cover can be costly,” she said.

In late February,the insurance council called on the next federal government to increase its investment in resilience measures to protect homes from flood and cyclones to $200 million a year,which it says should be matched by the states and territories in line with a 2014 Productivity Commission recommendation.

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