Skip to main content
U.S. flag

An official website of the United States government

Tropical Cyclones Are Intensifying More Quickly

Island nations bear brunt of powerful storms, scientists say

Photo of coastline near Gulfport, Mississippi, devastated by Hurricane Katrina.
Courtesy of NOAA Corps

Tropical cyclones are growing more powerful more quickly, according to a study of intensification rates by NCEI and its research partners. 

And those powerful storms are causing heavy damage in impoverished nations that can least afford to bear the costs, causing public health problems that illustrate “environmental injustice,” according to an article in a major medical journal. 

Two articles, both coauthored by NCEI’s Jim Kossin, suggest that coastal areas should prepare for rapidly intensifying storms, and that public officials should take action to protect vulnerable populations from the brunt of storms. 

Tropical cyclones—usually referred to as hurricanes in the Western Hemisphere—cause immense human suffering and economic loss. According to the NCEI U.S. Billion-Dollar Weather and Climate Disasters database, since 1980 the U.S. has sustained 258 disasters where overall damages have exceeded $1 billion (in Consumer Price Index-adjusted terms). From 1980 through 2019, there were 44 billion-dollar tropical cyclones that together killed more than 6,500 people and caused $945.9 billion in damages in the U.S. Hurricanes are the most costly of all weather and climate disasters.

Hurricane Intensification Rates

Tropical cyclones that intensify rapidly—sometimes jumping from Category 1 to Category 5 in a few days—are the most difficult to forecast, according to a paper in Nature Communications. This can lead to forecasting errors and potentially disastrous consequences when coastal areas are not given adequate time to evacuate. 

Given the dangers posed by rapidly intensifying hurricanes, researchers have begun to ask whether such storms are becoming more frequent because of climate change. The answer is yes, according to the 2019 paper.

Researchers used two observational datasets to calculate 24-hour wind speed changes in tropical cyclones from 1982–2009. Both datasets showed significant increases in tropical cyclone intensification rates in the Atlantic basin during that time, according to lead author Kieran Bhatia of NOAA Geophysical Fluid Dynamics Laboratory and his coauthors, including NCEI’s Kossin. 

In experiments using models, the authors found that these increasing intensification rates are more significant than would be expected from natural variability and are likely linked to anthropogenic (human-caused) climate change. Other studies have shown that the biggest jumps in intensification rates have happened in areas with the greatest increases in sea surface temperatures, suggesting that the more powerful storms are feeding off warmer waters. More reliable data will be needed to detect whether the same trend toward rapid intensification is operating at the global scale, the authors state.

Given this trend of more storms growing more powerful more quickly, the authors conclude that coastal areas may want to move ahead quickly with preparing for future storms. 

Hurricanes and Environmental Injustice

Those preparations should take public health into account, according to the second article, a recent Perspective piece in the New England Journal of Medicine (NEJM) that advocates several steps to reduce widening health gaps.

Hurricanes have profound effects on health, as people in the path of the storm face power outages, water contamination, food shortages, and mental health risks including anxiety, depression, and post-traumatic stress disorder. These problems can be especially acute for small island states in the Caribbean, where hurricanes are common but infrastructure is often substandard. The impacts of Hurricane Maria on Puerto Rico in 2017, and of Hurricane Dorian on the Bahamas in September 2019, illustrate the region’s vulnerability. 

The NEJM article describes these problems as one symptom of  “a double environmental injustice”—socioeconomically disadvantaged regions suffer disproportionately from human-caused climate change, yet they have contributed virtually nothing to global carbon emissions, which is considered the underlying driver. In other words, residents of these areas are victims of a problem they didn’t create. 

This injustice calls for action, according to the article, written by James Shultz of the University of Miami Miller School of Medicine and coauthors, including NCEI’s Kossin. They advocate safer housing, stronger electrical grids, storm-ready hospital facilities, and better warning systems. To bring about these changes, the authors urge stronger collaboration among climate scientists, public health researchers, and medical clinicians.

“Sea levels will not recede, average global temperatures will not decline, and hurricane hazards will not moderate,” the authors write. “We need to prepare now for future Dorian-like scenarios in a manner that redresses environmental injustice.”