Human-caused climate change made Atlantic hurricanes about 18 miles per hour (29 kilometers per hour) stronger in the last six years, a new scientific study found Wednesday.
For most of the storms -- 40 of them -- the extra oomph from warmer oceans made the storms jump an entire hurricane category, according to the study published in the journal, Environmental Research: Climate. A Category 5 storm causes more than 400 times the damage of a minimal Category 1 hurricane, more than 140 times the damage of a minimal Category 3 hurricane and more than five times the damage of a minimal Category 4 storm, according to the National Oceanic and Atmospheric Administration
For three storms, including this month's Rafael, the climate change factor goosed wind speed so much that the winds increased by two storm categories.
This isn't about more storms, but increasing power from the worst ones, authors said.
"We know that the intensity of these storms is causing a lot more catastrophic damage in general," lead study author Daniel Gifford, a climate scientist at Climate Central, which does research on global warming. "Damages do scale (up) with the intensity."
The effect was especially noticeable in stronger storms, including those that made it to the top of the Saffir-Simpson scale of storm intensity: Category Five, study authors said. The study looked at 2019 to 2023, but the authors then did a quick addition for the named storms this year, all of which had a bump up due to climate change.
"We had two Category Five storms here in 2024," Gifford said. "Our analysis shows that we would have had zero Category Five storms without human-caused climate change."
This year's three most devastating storms -- Beryl, Helene, and Milton -- increased by 18 mph (29 kph), 16 mph (26 kph) and 24 mph (39 mph) respectively because of climate change, the authors said. A different study by World Weather Attribution had deadly Helene's wind speed increase by about 13 mph, which is close, said Imperial College of London climate scientist Friederike Otto, who coordinates the WWA team and praised the Climate Central work.