More frequent and stronger cyclones as a result of climate change are expected to increase damage costs

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[SANTIAGO] Tropical cyclone damage costs will increase four-fold to US$109 billion a year across the world by 2100, according to a study published in Nature Climate Change last week (1 February).

Predicted increases in population and economic activity by 2100 will increase cyclone damage costs to US$56 billion a year — more than double the current figure of US$26 billion.

And more frequent and stronger cyclones as a result of climate change are expected to add a further US$53 billion a year to the bill, the study reveals, quadrupling the total annual cost.

The researchers adapted an existing technique that uses climate models to predict the frequency, intensity and location of tropical cyclones in each of the world's ocean basins. They tracked the anticipated path of 17,000 storms and calculated the damage when the storms struck land.

China and the United States will suffer the highest annual damage, the study predicts — US$25 billion and US$15 billion, respectively — as they will have the largest economies.

Damage costs will also increase rapidly in East Asia, and Central America and the Caribbean, where economic growth is expected to be high.

"Hurricane damage in the Central America and Caribbean region — currently about US$2 billion a year — will rise to US$14.7 billion a year by 2100, US$4.7 billion from increased assets and US$10 billion from climate change-related cyclone damage," lead author Robert Mendelsohn, a researcher at the Yale School of Forestry and Environmental Studies, United States, told SciDev.Net.

Several islands in the Caribbean 'hurricane alley' will be particularly badly affected, he said, because coasts are vulnerable to cyclones and hurricanes there affect the whole nation.

Economic damage from tropical cyclones is predicted to be less than US$1 billion a year in Europe and South America because they have fewer storms, and in Africa because "there is relatively little in harm's way", the paper says.

William Nordhaus, who studies the impact of tropical cyclones at the Yale centre but was not involved in the study, told SciDev.Net that "the paper's innovation was to simulate future tropical cyclones and make damage estimates for other countries. More work along the same lines and the development of alternative cyclone simulation models would be useful."

But Judith Curry, an atmospheric scientist at the US-based Georgia Institute of Technology, said she did not see the point in making projections 90 years in the future. "The uncertainties are huge: 10–30 years would be more plausible — and more useful."

Link to full paper in Nature Climate Change