Hurricanes Are Strengthening Much Faster Than They Did in the 1980s

It is thanks to researchers like Andra Garner that your creeping suspicion that things are getting worse can be statistically confirmed — and quantified. On Thursday, Scientific Reports published Garner’s new study, which found that Atlantic hurricanes are “more than twice as likely to strengthen from a weak Category 1 hurricane to a major Category 3 or stronger hurricane in a 24-hour period than they were between 1970 and 1990.” She also found that for hurricanes off the East Coast, that intensification is more likely than ever to happen quickly.

“Most of these findings have served to better quantify and describe a phenomenon that is very much expected in a warmer climate,” Garner, an assistant professor at Rowan University’s Department of Environmental Science, told me over email. “That means that there weren’t necessarily any surprises.”

But that doesn’t mean the findings aren’t invaluable for our understanding of how, precisely, hurricanes are getting more dangerous in our warming world. “I would say, the increased likelihood for hurricanes to transition from weak storms into major hurricanes in 36 hours or less was particularly striking to me, especially since statistical analyses indicated that it would have been impossible to observe this increase if the frequency with which intensification events cause storms to evolve from relatively weak storms into major hurricanes had not changed since the historical era,” Garner added.

For her analysis, Garner looked at wind speed changes over the lifespan of every Atlantic hurricane to form during three different eras: the “historic era,” between 1970 and 1990; the “intermediate era,” between 1986 and 2005; and the “modern era,” between 2001 and 2020. She found that the probability that a hurricane’s maximum intensification rate was 20 knots (about 23 miles per hour) or more during a 24-hour period jumped from 42.3% during the historic era to 56.7% in the modern era. It is also more likely that modern hurricanes will strengthen from weak storms into major hurricanes in the span of a day, up to 8.12% from just 3.23% during the historic era.

Scientists have long understood that climate change is fueling stronger hurricanes, primarily because warmer oceans basically act as Redbull for storms — by one commonly cited estimate, every 1 degree Celsius increase in ocean temperature adds a 50% increase in the storm’s “destructive potential.” But Garner sees the purpose of her research as less about the awesome power of these modern storms — four of the five most economically damaging Atlantic hurricanes have occurred since 2017, her paper notes — and more about what this rapid intensification will mean when it comes to future forecasting and emergency planning. “I think these findings should really serve as an urgent warning for us,” she stressed to me. Though she didn’t look at future projections for this analysis, she believes it’s “reasonable to expect that without major changes in our behavior, and a rapid transition away from fossil fuels, this is a trend that will continue to get more extreme.”

Garner, though, doesn’t want all this to be digested as just more bad news even if it might seem that way from the top line. “[I]t is really critical to remember that there is definitely still hope,” she told me. “Because human-caused warming has created conditions in which hurricanes can strengthen more quickly, we’re the cause of this problem — which means we can also be the solution.”