One study suggests that tropical cyclones are less frequent in the man-induced period of climate change. -Image of the public relations brochure
Australia could experience fewer tropical cyclones as climate change remains in place, a new study suggests.
Researchers say 13% fewer cyclones form each year than before human emissions began to warm tropical oceans.
The findings are based on the careful reconstruction of a long-term global record of the frequency of tropical cyclones dating back to the mid-19th century.
“For most tropical cyclone basins, including Australia, this decline has accelerated since the 1950s, when warming has become unprecedented,” says the study’s lead author. Savin Chand, of Federation University Australia.
Global warming is believed to have affected atmospheric circulation, making it more difficult for cyclones to form.
Chand says the work is a big step forward in understanding long-term trends, with previous studies based on short-term observational data from the age of satellites dating back only about 50 years.
“In the past several studies have emerged, using this short period of data that came to different conclusions, contradictory conclusions, about what is happening with the trends,” he said.
“This long-term dataset now offers us better ways to quantify how human-induced climate change has affected the number of cyclones.”
Chand noted that while fewer cyclones might be good news, frequency is just one aspect of the risk associated with tropical cyclones.
“The geographical distributions of cyclones are changing and tropical cyclones have become more intense in recent decades,” he said.
“In some parts of the world, they are also approaching coastal areas where populations and developments are growing.”
Along with the increase in cyclone-related rainfall and the slower decay of hurricanes that make landfall, Dr. Chand said these changes could be contributing to the “accumulated” damage from cyclones in the world’s tropical regions.
But these other factors were not part of the study and therefore no direct conclusions can be drawn about the general changes in risk.
The study involved a team of Australian and international scientists and has been published in the journal Nature Climate Change.