New study finds 50-year trend in hurricane escalation linked to climate change

New research by Rowan University climate scientist Dr. Andra Garner indicates that there have been great changes to Atlantic hurricanes in just the past 50 years, with storms developing and strengthening faster.

An assistant professor of environmental science in Rowan's School of Earth & Environment, Garner documented this week in the journal Nature Scientific Reports ("Observed Increases in North Atlantic Tropical Cyclone Peak Intensification Rates") that from 1971 through 2020, intensification rates from Atlantic hurricanes have changed as human-caused greenhouse gas emissions warmed the planet and its oceans.

Atlantic hurricanes developed faster, from a weak Category 1 hurricane to a major Category 3 or stronger, in a 24-period than they did between 1970 and 1990 and they are now more likely to strengthen faster along the east coast of the U.S. than they were during that period, Garner found. She also concluded that better communication methods are needed to warn at-risk communities as it's difficult to predict when, exactly, hurricanes will strengthen fastest.

Garner showed that from 2001 through 2020, considered for the study's purpose the "modern era," that hurricane intensification rates were up to 28.7 percent greater than they were from 1971 through 1990, a period she identified as the "historical era."

"In the modern era, it is about as likely for hurricanes to intensify by at least 57 mph in 24 hours, and more likely for hurricanes to intensify by at least 23 mph within 24 hours than it was for storms to intensify by these amounts in 36 hours in the historical era," she said. "The number of times that hurricanes strengthen from a Category 1 storm (or weaker) into a major hurricane (Category 3 or greater) within 36 hours has also more than doubled in the modern era relative to the historical era."

Garner said ever-warming ocean waters, such as the record-high temperatures reported this summer off the coast of Florida, are especially troubling, because tropical storms feed off energy in ocean water and the warmer the water, the greater the amount of energy such storms can draw.

For example, she said, September's Hurricane Lee, a massive Category 5 that was the third-fastest intensifying storm in recorded history, virtually exploded because of the unnaturally warm Atlantic waters.

"More than 90 percent of the warming we're seeing from human-caused greenhouse gases goes into our oceans," Garner said.

Based on data from the National Hurricane Center, Garner's research shows a pattern of rapid escalation that is quickly changing.

"The increase in the number of times hurricanes turned from Category 1 or weaker to a major storm, (Category 3 or greater), is particularly concerning, since major hurricanes often produce the most damage in our coastal communities," she said.

Ultimately, she said, proof of quicker intensifying hurricanes as the planet has warmed should serve as a warning that humans must heed.

"One of the messages from this work is that there is an urgency," Garner said. "If we don't make some pretty big changes and rapidly move away from fossil fuels, this is something we can expect to see worsen in the future."