Climate change is already having an impact on extreme weather events in Australia – and scientists warn worse is still to come.

The Critical Decade: Extreme Weather, published by the Climate Commission, says urgent action must be taken.

But stabilising the climate “is like turning around a battleship”, it says. Even if greenhouse gas emissions are cut now, extreme weather will continue to grow in frequency and severity over the next few decades.

The report says all extreme weather events are now influenced by climate change and damage from heatwaves, heavy rainfall, drought, bushfires, coastal flooding and cyclones is likely to increase in coming years.

While the insurance industry might be expected to be among the leading supporters of the report – which has been condemned in some quarters as alarmist – its initial reaction has been one of polite interest.

That’s mainly because many specialists believe the report’s linking of extreme weather events and climate change is based on short-term experience. In other words, there has to be more data, and the only way to establish the link with full certainty is going to take time.

This is the catch-22 of the debate for insurers. They focus only a couple of years out in their planning for loss events, and tend to rely more on actual experience of such events to establish trends.

So while the commission is making a valid point, the data is insufficient at this point for insurers to act on it.

One of the report’s authors, academic Will Steffen, likens the situation to an athlete using performance-enhancing drugs.

“We now have a climate on steroids,” he told insuranceNEWS.com.au.

Although Australia has always had heatwaves and hot days (above 35ºC), climate change has increased their intensity, the report says.

In 102 years there have been only 21 days with an average maximum temperature across Australia of more than 39ºC. Eight of them were last summer.

“As climate change continues, it is virtually certain Australians will face extreme hot weather much more often and the impacts will become more severe,” the report says.

Heavy rainfall and flooding is also likely to worsen; higher temperatures in the oceans lead to more evaporation – and because the atmosphere is warmer, it can hold more water vapour.

The report says climate change probably contributed to the 2010/11 Queensland floods, which killed at least 33 people and cost an estimated $5 billion.

Droughts may also intensify, with potentially devastating effects on agriculture.

Dry regions will become drier and wet regions wetter, the commission says.

Conditions that favour devastating bushfires – such as those of Black Saturday in 2009, which killed 173 people, injured 414 and destroyed 2029 homes – could become more prevalent.

“The projected increases in hot days across the country, and in consecutive dry days and droughts in the southwest and southeast, will very likely lead to increased frequency of days with extreme fire danger in those regions.”

Rising sea levels are expected to bring more coastal flooding, the report says.

The global sea level has risen by 0.21m since 1880 and could grow another 1.1m by the end of the century, putting 157,000 to 247,600 buildings at risk in Australia.

Tropical cyclones, although not likely to increase in number, will cause more damage, the report claims.

Professor Steffen says the insurance industry must respond.

But the short-term focus of the industry makes that difficult. The Insurance Council of Australia (ICA) says while many climate change forecasts consider possible risks 50 to 100 years from now, insurers look just one or two years ahead.

No insurer covers gradual change in sea levels or other anticipated impacts of global warming, a spokesman told insuranceNEWS.com.au.

However, adaptation to extreme weather, including mitigation measures such as levees, dams and barrages, is essential and ICA is working with the Government to promote this.

The Climate Commission’s report is another valuable step towards building awareness of the scale of the global warming problem. Insurers are far from being sceptical, but they do appear to believe the link between extreme weather and climate change is, for now, tenuous.