Warming doubles intense cyclone risk

Climate change will more than double the probability of intense tropical cyclones across much of the world within the next few decades and Australia is in the firing line, a new study suggests.

Tropical cyclone risk researcher Nadia Bloemendaal and a team of international scientists have come up with a novel method that combines historical cyclone data with global climate models to understand what the future might hold.

Their results suggest the probability of intense tropical cyclones - category three or higher on the international Saffir-Simpson wind scale - more than doubling in all regions except for the Bay of Bengal and the Gulf of Mexico.

The modelling also found a likely decrease in the frequency of weaker weather systems such as tropical storms.

Many of the most at risk locations are low-income countries. Those expected to see an increased risk by the middle of this century include many Pacific Island Nations, such as the Solomon Islands and Tonga.

Dr Bloemendaal is a researcher at the University of Amsterdam's Institute for Environmental Studies.

She says the datasets that underpin her work are publicly available, meaning governments, insurers and others can use them to analyse cyclone risks more accurately for every individual coastal city or region in the world.

When they were applied to Cairns, the chance of an intense tropical cyclone - category three or higher on Australia's scale - went from around once every 50 years in the past, to once every 30 years in the near future.

"And the chances of a category 5 near Cairns have gone from once every 2500 years in the past to once every 300 years within the next few decades. We're talking about an eight-fold increase."

Dr Bloemendaal hopes her work will be a wake up call for governments who need to be preparing now to limit risks to life, property and ecosystems.

Dr Ivan Haigh from the University of Southampton in the UK says it's a major concern that some regions that don't currently get tropical cyclones are considered likely to in the near future.

"The new tropical cyclone dataset we have produced will greatly aid the mapping of changing flood risk in tropical cyclone regions."

The research has been published in the journal Science Advances.