Hurricanes and cyclones affected nearly 800M people in 2019, doubling 2002's figure

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The number of people affected by tropical cyclones nearly doubled from 2002 to 2019, when the powerful storms reached nearly 800 million people, according to a new study published in the scientific journal Nature.

Using new wind modelling techniques, researchers from Stanford University, Johns Hopkins University and public policy think tank RAND Corporation found that every region of the world typically affected by tropical cyclones – including hurricanes and typhoons – saw an increase in the number of people exposed to the intense storms during this period.

"Although our study period is not sufficiently long to understand long-term trends, we observe a steady increase in both population and person-days exposure for all storm intensities in the past two decades,” said Renzhi Jing, lead author and a postdoctoral scholar at Stanford University, in a media release.

Moreover, the authors said they expect cyclones to become more intense and possibly more frequent as the climate continues to warm. While they estimate population growth accounts for about one-third of the increase in exposure, they say changes in cyclone behaviour account for the remainder of the increase.

"The increased exposure to cyclones is attributed more to changes in tropical cyclone weather patterns than to population growth,” said Zachary Wagner, senior author of the study and an economist at the RAND Corporation, in the media release.

"Given projections of increased storm intensity going forward, it’s reasonable to expect a continuing increase in the number of people exposed to the most intense storms, which poses many challenges for the future."

Jing, Wagner and their co-authors estimate that between six and 12 per cent of the global population is exposed to tropical cyclones each year, with the highest concentration living in Asia.

And while the growing intensity of cyclones is being felt around the world, their exposure has a disproportionate impact on low- and middle-income countries, especially in regions where resilience is limited.

The study estimates that coastal eastern Asia accounted for 43 per cent of all the tropical cyclone exposure measured from 2002 to 2019, South East Asia for 24 per cent, eastern India and the Bay of Bengal for 14 per cent, the Korean peninsula and Japan for six per cent, North and Central America for five per cent and the Caribbean for three per cent.

In addition to finding that the Global South — which is broadly defined as nations with a relatively low level of economic and industrial development compared to more industrialized nations to the north — bears the brunt of tropical cyclone exposure, the study found that within a given country, people exposed to cyclones are more likely to be "socioeconomically deprived" than those who aren't exposed, especially in the case of high-intensity storms.

When tropical cyclones pass over populated areas, the combination of high winds, low pressure systems, heavy rainfalls and storm surges can lead to large-scale destruction and increased risk of death and disease.

For that reason, the authors say documenting the patterns and vulnerabilities of exposed populations is important to help develop mitigation strategies "and assess the global burden and future risks of tropical cyclones."

In fact, one of the issues on the agenda during this year's United Nations Climate Change Conference was how the Global South suffers disproportionately from the impacts of the climate crisis, despite contributing less to climate change than more industrialized nations.

"Our countries, our communities are suffering so much," Ugandan climate activist Evelyn Achan told The Associated Press at a protest during the summit calling for more money for climate change adaptation.

"We don’t have the money to adapt to the climate crisis and yet we do not cause the climate crisis, we are least responsible for the climate crisis. So, we’re demanding for leaders to put in place adaptation finance."