Spinning south The warming climate could bring more catastrophic hurricanes to ill-prepared areas of Australia’s coast
W
hen Cyclone Seroja slammed into the West Australian holiday town of Kalbarri in April it carved a trail of destruction that is sadly familiar to many coastal communities in the nation’s north. Roofs were peeled away from houses, windows smashed and debris scattered far and wide, leaving devastated residents to count the cost to properties and livelihoods. But this storm was different from some that preceded it in a couple of ways: its formation under the rarely seen Fujiwhara Effect, in which it absorbed the weaker Cyclone Odette before shifting its trajectory south-eastwards; and its final destination. Category 3 cyclones are rare visitors to Western Australia’s Mid West coast. “It appears to be one of the more intense tropical cyclones to make landfall that far south on the Western Australian coast,” James Cook University Professor of Physical Geography Jonathan Nott told Insurance News in the days after the catastrophe. Risk modeller AIR Worldwide noted it is “extremely rare for tropical cyclones to travel this far south”, with Geraldton, 155km south of Kalbarri, taking a hit after avoiding such storms since 1956. Professor Nott, who specialises in reconstructing long-term natural records of extreme events, called it a
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possible wake-up call for Australia, and a sign of things to come. That’s because in a warming climate, cyclones could track further south more often. In September last year the National Centre for Atmospheric Research and insurer IAG released a research paper examining climate change impacts on “weather extremes that produce significant property, personal and economic damage and hardship” in Australia. Among its key findings was that the frequency of tropical cyclones has declined slightly in recent decades “and this slow trend is projected to continue globally and for the Australian region”. However, the good news ends there. “Over the past 30 years, the proportion of the most intense tropical cyclones has increased at the expense of weaker systems, and this change is expected to continue,” the report says. “Over the past two decades, the number of intense tropical cyclones making landfall on the Queensland east coast has increased substantially. The frequency of tropical cyclones making landfall throughout the western South Pacific region has also increased. “There is global evidence of a poleward shift in the latitudes where tropical cyclones reach their peak
