Hurricanes Helene and Milton, like dozens of others, energized by climate change, report says

Hurricanes in the Atlantic Ocean Basin are running on average a category stronger on the Saffir-Simpson Hurricane Wind Scale than they would be without climate change and its associated warming, according to a new study released Wednesday.

The research, published by Climate Central, studied hurricanes from 2019 through 2023 and found that their peak wind speeds were, on average, 18 mph higher compared to the expected strength without the influence of human-caused warming. And using those calculations, researchers have estimated that all 11 hurricanes of this past season were energized in some way by climate change.

Researchers found a significant driving force behind the boost in storm intensity is coming from persistent above-average to record warmth in the waters across the Atlantic Basin. Water temperatures well exceeded previous record heat measurements in 2023 and maintained those levels as high as 3 degrees above average throughout 2024.

WHAT RECORD-SETTING OCEAN TEMPS MEAN FOR SEA LIFE AND 2024 HURRICANE SEASON

Hurricanes draw their power from warm water. The warmer the waters, the more energy is available for hurricanes to produce devastating wind speeds that, in turn, generate higher storm surges and heavier rainfall.

The published study looked at 30 hurricanes from 2019 through 2023, and among its findings – aside from the overall average wind boost of 18 mph for 84% of the storms in those years – three hurricanes were able to reach Category 5 status due to climate change: Hurricane Lorenzo in 2019, Hurricane Ian in 2022 and Hurricane Lee in 2023.

In addition, hurricanes Sally (2020), Ian and Franklin (2023) would have been a category weaker had ocean temperatures been at historical averages, researchers said.

2024 hurricane season supercharged by climate change too

While the published paper’s findings stretched through the 2023 season, Climate Central has applied the paper’s calculations to the 2024 season and found similar daunting results.

Continued record-warm ocean temperatures boosted the intensity of all 11 Atlantic hurricanes by a range of 9-28 mph. Five of the 11 hurricanes this season found their way into a Gulf of Mexico that was 2 degrees warmer than had climate change not been a factor, researchers said.

Researchers singled out Hurricane Milton, which raced through Florida with 100-plus-mph winds and caused storm surge damage around Florida’s Gulf Coast.

“Hurricane Milton rapidly intensified by 120 miles per hour in less than 36 hours over waters whose temperatures were made 400-800 times more likely by climate change,” the report stated.

The report found that neither Milton, which reached Category 5 status in the Gulf of Mexico before dropping to a Category 3 at landfall, nor Hurricane Beryl, which reached Category 5 status at the start of July and became the earliest Category 5 storm on record, would have been unlikely to reach that top rung without climate change effects.

Researchers attributed climate change to allowing seven other hurricanes this season to reach a level higher on the Saffir-Simpson Scale, and pushed tropical storms Debby and Oscar into hurricane status.

For Hurricane Helene, which killed more than 240 people across the Southeast with torrential rains and damaging winds, extra-warm water temperatures added 16 mph to the storm’s eventual strength, while Hurricane Milton received a 24-mph increase in peak wind speed, according to the report.

“Every hurricane in 2024 was stronger than it would have been 100 years ago,” said Daniel Gilford, Ph.D., a climate scientist at Climate Central and lead author of the study and report. “Through record-breaking ocean warming, human carbon pollution is worsening hurricane catastrophes in our communities.”