This article discusses the impacts of hurricanes “Helene” and “Milton” in the southeastern USA, highlighting the devastating effects of “Helene,” which resulted in over 230 fatalities and significant damage. Experts from the World Weather Attribution have linked climate change to increased hurricane intensity and rainfall, with noted statistical analyses showing heavier precipitation and stronger winds. The article also addresses the rising costs of hurricane damage due to population growth and infrastructure development in vulnerable areas, particularly Florida.
This year, the southeastern United States has experienced two devastating hurricanes. The first was “Helene,” swiftly followed by “Milton.”
The impacts of “Helene” were particularly severe: Many small rivers in North Carolina, South Carolina, Tennessee, and Georgia overflowed due to heavy rainfall, leading to the destruction of roads, bridges, and homes. Tragically, over 230 lives were lost, marking “Helene” as the deadliest tropical cyclone in the U.S. since “Katrina” in 2005.
After such extreme weather events, there is often public speculation about the role of climate change. Recently, scientists have been quick to respond with provisional analyses. Their findings this time are particularly compelling: climate change has intensified both hurricanes, notably manifested in increased wind speeds and rainfall.
Understanding Climate Change’s Role
A notable group of experts, known as “World Weather Attribution” (WWA), specializes in analyzing the causes of extreme weather events. Various teams swiftly publish their findings, relying on trustworthy methodologies despite the lack of formal peer review.
The WWA scientists have closely examined “Helene.” Their research indicates that climate change has led to approximately a 10 percent increase in rainfall. Winds along Florida’s coast were about 21 kilometers per hour stronger due to global warming. Furthermore, the high sea temperatures in the Gulf of Mexico have become 200 to 500 times more likely than in the past, thus propelling the hurricane’s strength.
To assess climate change’s impact on rainfall from tropical cyclones, researchers used computer models, simulating numerous weather events both before and after global warming, with current temperatures roughly 1.3 degrees Celsius higher. They particularly focused on areas that experienced the most fatalities: parts of the southern Appalachians and northern Florida.
The scientists utilized the “Imperial College Storm Model,” a sophisticated computational tool from Imperial College London, offering enhanced simulation capabilities for hurricanes compared to traditional weather forecasting models.
Rainfall Increases with Rising Temperatures
Researchers agree that the WWA’s results seem plausible. According to Theodore Shepherd from the University of Reading, the expectation is that rainfall will rise by approximately 7 percent for each degree of warming. Given the Earth’s rise of 1.3 degrees Celsius since pre-industrial times, this equates to about 9 percent more precipitation per severe weather event.
Moreover, not only could hurricanes themselves grow stronger, thus releasing more energy, but this could also magnify climate change’s impact on rainfall.
Michael Wehner from Lawrence Berkeley National Laboratory agrees, suggesting the effects of climate change may be even more profound than what WWA reported. Increased energy translates into stronger updrafts, enhancing a hurricane’s ability to convert moisture into rainfall.
Thomas Knutson from NOAA acknowledges the agreement amongst experts but points out an area needing further research: the formal verification of increased precipitation rates in tropical cyclones remains unaddressed.
Though the WWA has yet to publish an in-depth analysis for “Milton,” preliminary assessments suggest that Florida experienced 20 to 30 percent more rain in a single day due to this hurricane, which reached category 3 strength upon landfall—about a category 2 without global warming. The robustness of these statements awaits further examination.
Low Hurricane Experience in Mountainous Regions
The WWA’s analysis indicates that “Helene” caused the most devastation in mountainous areas far from the coast. Limited cellphone and internet connectivity, coupled with a lack of hurricane experience, hampered evacuation efforts.
In contrast, “Milton,” which primarily affected Florida and spared other states, resulted in fewer fatalities, with only 23 lives lost. This can be attributed to Florida’s familiarity with hurricanes and better preparedness compared to its neighboring states severely impacted by “Helene.”
According to Moody’s, the two hurricanes in the U.S. collectively caused insured losses between 35 and 55 billion dollars, with higher estimates also being mentioned.
Disinformation on Social Media
As recovery efforts continue, unfounded conspiracy theories regarding these hurricanes have begun circulating on social media platforms. Some claim the hurricanes’ severity was caused by technical manipulation or that there has been a dramatic increase in powerful hurricanes.
However, these claims lack any substantive evidence. Hurricanes are too vast for any form of technological interference, and while there’s been a slight uptick in intense hurricanes, it doesn’t approach the dramatic levels suggested. Such theories have gained traction, likely influenced by the ongoing presidential election campaign in the U.S.
On the other hand, solid evidence points to the factors that have genuinely enhanced the intensity