The Japan Times - Climate Change Intensified Atlantic Hurricanes, Study Finds

Human-caused climate change has significantly intensified Atlantic hurricanes, with elevated sea surface temperatures driving higher wind speeds for the majority of storms over the past five years and every recorded storm in the current season. A new analysis by Climate Central, published in the journal Environmental Research: Climate, quantifies this trend, showing that global warming has pushed hurricane intensities beyond what would be expected in a pre-industrial climate.

The study examined 38 hurricanes in the Atlantic Basin between 2019 and 2023. It found that climate change increased the maximum wind speeds of approximately 80% of these storms by an average of 18 miles per hour. Of the 38 storms analyzed, 30 reached intensities roughly one category higher on the Saffir-Simpson Hurricane Wind Scale than they would have in a world without human influence.

The research identified three specific storms that strengthened into Category 5 hurricanes—the strongest classification on the scale—due to climate change: Lorenzo in 2019, Ian in 2022, and Lee in 2023. The potential for damage from these winds escalates sharply with intensity; according to the National Oceanic and Atmospheric Administration (NOAA), damages associated with each category jump increase by roughly four times. Even wind speed increases that do not cross a category threshold can dramatically raise potential destruction.

Climate Central also released a separate report focusing on the 2024 Atlantic hurricane season, titled "Climate change increased wind speeds for every 2024 Atlantic hurricane." This analysis expanded the framework to cover all eleven hurricanes recorded in the basin so far in 2024. The findings indicate that maximum wind speeds for each of these storms were increased by between 3 and 14 miles per hour due to warmer ocean waters.

The study highlights Hurricane Milton as a prominent example of this dynamic. Data from Climate Central’s Climate Shift Index: Ocean shows that Milton rapidly intensified by 120 miles per hour in less than 36 hours while traversing waters whose record-setting temperatures were made 400 to 800 times more likely by climate change. These sea surface temperatures, often more than 3 degrees Fahrenheit above normal, would be virtually impossible without the influence of carbon pollution.

The analysis relies on data from NOAA and the National Hurricane Center. Climate Central noted that it has updated its methodology for calculating the influence of climate change on hurricane wind speeds to account for a more comprehensive set of thermodynamic factors. This adjustment affects the numbers showing changes in wind speed for each storm in the 2024 season, reflecting the organization's most current scientific approach. All future analyses for hurricanes in 2025 will utilize these new methods.

The report underscores the role of the Climate Shift Index: Ocean, a tool that measures the influence of climate change on daily ocean temperatures to connect human-caused warming to consequences such as rapid hurricane intensification. The index helps visualize how elevated sea surface temperatures provide additional energy for storms, leading to stronger winds and greater destructive potential.

Climate Central scientists emphasize that while the study focuses on wind speed increases, the broader implications include higher storm surges and more widespread flooding due to the overall strengthening of these systems. The organization provides open access to its data and methodology through its Extreme Weather Toolkit, which offers reporting resources and multimedia graphics for journalists and researchers.

The findings align with broader scientific consensus that a warming climate is making hurricanes more dangerous. As ocean temperatures continue to rise, the fuel for these storms becomes more abundant, increasing the likelihood of rapid intensification events where storms strengthen quickly over warm water. This trend poses growing risks to coastal communities, particularly those in the Atlantic Basin, which have seen a series of high-impact hurricanes in recent years.

Climate Central encourages the use of its online map tools to explore data showing which parts of the world are experiencing high Ocean Climate Shift Index levels. These tools allow users to view daily ocean temperature anomalies and share custom maps that illustrate the connection between climate change and extreme weather events. The organization continues to monitor the 2024 season and will update its analysis as new storms develop and data becomes available.

M.Sugiyama--JT