Human-caused climate change has increased Hurricane Helen’s damaging rainfall by about 10% and intensified its winds by about 11%, scientists said in a new rapid study released as powerful Hurricane Milton threatens the Florida coast in less than two weeks.
The warming climate increased Helen’s wind speeds by about 13 mph (20.92 kph) and made the high sea temperatures that fueled the storm 200 to 500 times more likely, according to World Weather Attribution calculations Wednesday from Europe. Ocean temperatures in the Gulf of Mexico were about 3.6 degrees Fahrenheit (2 degrees Celsius) above average, WWA said.
“Hurricane Helen and the storms that were occurring in the area anyway were exacerbated by the fact that the air is warmer and can hold more moisture, which means total precipitation — which, even without climate change, would have been incredibly high,” he said. “Given the circumstances, it was even higher,” Ben Clark, a co-author of the study and a climate researcher at Imperial College London, said in an interview.
The authors said it was likely that Milton would be similarly eradicated.
Scientists have warned that continued burning of fossil fuels will lead to more hurricanes like Helen, with “unimaginable” flooding inland, not just on the coasts. Many of those who died in Helen were victims of massive inland flooding, not strong winds.
Helen made landfall in Florida with a record storm surge of 15 feet (4.57 m) and catastrophic sustained winds of up to 140 mph (225.31 km/h), hitting Georgia, the Carolinas, Tennessee and Virginia. It devastated remote towns throughout Appalachia, leaving millions without power, cell service and supplies and killing more than 230 people. In the following days, search crews continued searching for bodies. Helen was the deadliest hurricane to hit the mainland United States since Hurricane Katrina in 2005.
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Helen dumped more than 40 trillion gallons of rain – an unprecedented amount of water – on the region, according to meteorologists’ estimates. The rainfall would have been much less intense if humans had not warmed the climate, according to WWA, an international scientific collaborative that conducts rapid climate attribution studies.
“When you start talking about the quantities involved, and when you add even just a small percentage on top of that, it makes it that much more devastating,” Clark said.
According to scientists’ calculations, severe hurricanes such as Hurricane Helen were previously expected to occur every 130 years on average, but today they are about 2.5 times more likely to occur in the region.
The WWA was launched in 2015 to assess the extent to which extreme weather events can be traced back to climate change. FAO’s rapid studies are not peer-reviewed but use peer review methods. The team of scientists tested the impact of climate change on Helen by analyzing weather data and climate models including the Imperial College Storm Model, the Ocean Climate Transition Index, and the standard WWA approach, which compares an actual event to what was expected in 2018. A world that did not warm by about 1.3 degrees Celsius since pre-industrial times.
A separate analysis of Helen last week by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory found that climate change caused a 50% increase in precipitation in some parts of Georgia and the Carolinas, and that the observed precipitation “was up to 20 times more likely in these areas.” Because of global warming.” This study was also not peer-reviewed but used a method published in a study on Hurricane Harvey.
Kim Cobb, director of the Brown Institute for Environment and Society, was not involved in either study. She said there is uncertainty about the extent to which climate change will affect storms like Helen, but we know that it increases the strength and destruction of these storms.
She said Helen and Milton should serve as a “wake-up call” for emergency preparedness, resilience planning and increased use of fossil fuels.
“Going forward, the additional warming that we know will happen over the next 10 to 20 years will worsen hurricane statistics, and we will break new records,” she said.
The analysis does suggest that climate change made possible higher sea temperatures that also caused the Milton to rapidly intensify. Clark said the two massive storms in quick succession illustrate the potential future of climate change if humans don’t stop it.
“As we head into the future and our results show that as well, we still have control over where it goes in terms of what risks we face in the future, what costs we pay in the future,” he said. “It just depends on how we change our energy systems and how many fossil fuels we burn.”
& Edition 2024 The Canadian Press
