Warmer World, Windier Storms: Climate Change Has Juiced Hurricane Speeds

In some ways the impact of hurricane-force winds is binary: either your roof comes flying off, or it doesn’t. As such, though it is now well understood and widely disseminated that water is the deadliest aspect of tropical cyclones, the specific wind speed that hits populated parts of land really makes a difference. At 100 mph, maybe important things hold; at 105, or 110, or 118.57 mph, maybe they don’t.

That last very specific number comes from a new study from researchers at the non-profit Climate Central (disclosure: I freelanced for them some a decade ago), which examined what a warming world, and specifically warmer ocean temperatures, are doing to hurricanes. They combined actual observations, computer modeling, and theories underlying how hurricanes form and grow, and examined the five-year period from 2019 through 2023.

The result is straightforward: warmer waters over which hurricanes form have indeed juiced their wind speeds, and not by a small amount: the storms over that five-year period had maximum winds that were on average 8.3 meters per second faster than they would have been in a world with no climate change at all. That’s equivalent to 18.57 miles per hour.

That difference is truly meaningful. Our theoretical storm with 100 mph winds is a category 2 storm on the Saffir-Simpson scale; add its warming-induced average bump, and you suddenly have a category 3, now considered a “major” hurricane. Before warming: “Extremely dangerous winds will cause extensive damage,” according to NOAA. After warming: “Devastating damage will occur.” The dangerous-to-devastating pipeline is not one anyone is interested in exploring. Add another 18 mph to a storm that would have landed at category 3 otherwise and suddenly “devastating” has become “catastrophic.”

The researchers did note that there are variations between individual storms in terms of how much the warming affects their wind speeds, but it is a fairly consistent finding that it does, in fact, have an effect. Of the 38 storms studied, 32 of them, or 84 percent, had “significantly” increased wind speeds because of the warmer waters they passed over.

“Quantifying and communicating the extent to which tropical cyclone intensities are attributable will ultimately enable stakeholders and the general public to more readily connect the dots between human-caused climate change and intense storms when they arise,” the authors wrote. It may help with hurricane preparedness, already a field that has advanced miles over the past few decades, but let’s not hold our breath on it meaning much for actual climate policy changes.