The study published in the journal Science Advances defined intense storms as the equivalent of a Category 3 hurricane or stronger. It noted that the likelihood of these storms will be higher in the coming decades, and more people will be affected by intense storms in some of the world’s most vulnerable regions.
The researchers also found that wind speeds in these storms could increase by up to 20%, as well as a huge increase in the frequency of category 4 and 5 storms — by more than 200% in some regions.
“Our results also reaffirm that regions that are currently at (very) low risk could really be affected by tropical cyclones in the wake of climate change,” says Nadia Bloemendaal, a climate scientist at the University of Amsterdam and lead author of the study, told CNN in an email. “We found it shocking to see how disproportionately many developing countries are at risk from future climate change.”
Researchers used a statistical forecasting system called STORM to generate 10,000 years of past and future climate conditions. They then used high-resolution wind speed maps to examine future changes at a local scale, “which is so important from a risk assessment perspective,” Bloemendaal noted.
The Hong Kong region and parts of the South Pacific have the highest likelihood of an increase in high-intensity storms, the scientists found.
Tokyo — the world’s largest metropolitan area with a population of around 38 million — currently has a 4.6% annual chance of being hit by a violent storm. In the future, scientists found that the number increases with a 13.9% probability.
Another notable jump was for Hawaii. Currently, Honolulu has a 4% chance of being hit by a major hurricane every year. In the coming years, that figure will be 8.6% — more than double, the study suggests.
The researchers said their findings were likely due to rising sea surface temperatures around the world. Sea temperatures have warmed dramatically in recent decades as a result of burning fossil fuels. The warmer water “will create more fuel for the storms to intensify,” Bloemendaal said.
The only regions where the scientists didn’t see a doubling of intense tropical cyclones in the future were the Gulf of Mexico and the Bay of Bengal. The frequency of intense storms remained “essentially unchanged” in the study, Bloemendaal noted, as atmospheric conditions there would become less favorable for tropical storms in the future.
“Global climate models project increased atmospheric stability over this region under future climate conditions,” Bloemendaal wrote. “Due to this improved atmospheric stability, the overall frequency of tropical cyclones in the Gulf of Mexico is expected to decrease as conditions have become less favorable for tropical cyclone development.”
However, she also found that when tropical storms form in these regions, the warmer water provides additional fuel for the cyclone to intensify to a Category 3 or higher.
So while these scientists expect fewer storms overall in the Gulf of Mexico or Bay of Bengal, they will be extremely powerful and costly.
rising costs
Hurricanes and typhoons are responsible for more financial losses than any other natural disaster. In the past decade alone, the study found that the United States has suffered $480 billion in losses from tropical storms and hurricanes.
Bloemendaal said this is one of the reasons why it is more important than ever to be able to predict where the strongest storms will occur in the future.
“Our findings can help identify the locations where the risk of tropical cyclones is greatest,” Bloemendaal said in a statement. “Local governments can then take action to reduce risk in their area, so damage and deaths can be reduced.”
Around the world, 80 to 100 tropical cyclones form each year. But reliable records for these storms — once only observable from ships or when they land — only date back to the 1960s, when scientists had weather satellites. This has made it difficult to predict long-term changes amid the climate crisis.
With this new research, scientists say the world will have a clearer picture of what the future holds for nature’s most destructive phenomenon worldwide.