Decline in tropical cyclones linked to climate change, study finds

Waves crash against Montevideo's Rambla in Uruguay during the passage of a subtropical cyclone on May 17, 2022. PHOTO: AFP

SYDNEY (XINHUA) - A team of Australian and international researchers have charted the frequency of tropical cyclones since 1850, and found that an accelerating decline is a likely consequence of climate change.

The research, published in the Nature Climate Change journal on Tuesday (June 28), found that tropical cyclones had declined by approximately 13 per cent during the 20th century, a trend that has been accelerating since the 1950s.

Lead author on the paper and meteorologist from Federation University, Dr Savin Chand, told Xinhua on Tuesday it is the first time modern and historical data has been combined to chart global cyclone trends.

"We have reconstructed tropical cyclone numbers back to the 1850s using the 'Twentieth Century Reanalysis' dataset, and together with high-resolution climate model experiments, we have quantified for the first time how cyclone numbers have changed over the past century," Dr Chand said.

The findings were unexpected as changes in sea surface temperatures would normally intensify storms, but Dr Chand said associated changes in atmospheric circulations could also prevent storms from forming.

"As the climate has warmed over the 20th century, underlying atmospheric conditions ... have created an environment that is less conducive for tropical cyclone formation globally," he said.

The problem arises in the intensity and location of tropical cyclones. The team found that tropical cyclones had been getting closer to coastal areas in parts of the world, and were growing more intense in recent decades.

Dr Chand said while this study focused on the frequency of cyclones over time, the team hopes to look at how other characteristics of cyclones have been evolving over the past century.

"Going forward, it is anticipated that continued improvement in climate model products and in observational datasets can help identify attributable anthropogenic climate change signals on other metrics such as tropical cyclone intensity and landfalling activities," he said.

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