In recent years, the frequency and intensity of hurricanes have increased, and many scientists point to global warming as a significant factor. Climate Scientists predicted, back in May this year, that this year’s hurricane season would be 85% above normal. While hurricanes often feature in the news, the link to climate change and global warming usually isn’t made clear. So how exactly does global warming contribute to the increased ferocity of these storms?
Warmer Oceans act like fuel
Hurricanes draw their energy from warm ocean waters. As global temperatures rise, so do sea surface temperatures. This additional heat provides more energy for hurricanes, allowing them to become more powerful. Studies have shown that the likelihood of a tropical cyclone developing into a major hurricane (Category 3 or higher) has increased by about 8% per decade since 1979 due to human-caused warming. As the planet warms due to increased greenhouse gas emissions, these conditions are becoming more prevalent, leading to more intense hurricanes.
Rapid Intensification
One of the most concerning trends is the phenomenon of rapid intensification, where a storm’s wind speeds increase dramatically in a short period. Milton's winds had increased from 80 to 175mph (129 to 282 km/h) in just 24 hours. Warmer waters and higher atmospheric moisture levels contribute to this rapid strengthening. This leaves less time for communities to prepare and can lead to more devastating impacts.
While the overall number of hurricanes may not be increasing, the storms that do form are more likely to be intense. The proportion of very intense (Category 4 and 5) hurricanes is projected to increase globally with continued warming. This means that even if the frequency of hurricanes remains the same, the potential for catastrophic damage is higher.
Increased Rainfall and Flooding
Global warming also leads to higher atmospheric moisture content, which results in heavier rainfall during hurricanes. This can cause severe flooding, compounding the damage from high winds and storm surges. Rising sea levels, another consequence of global warming, exacerbate this issue by increasing the height and reach of storm surges. This was seen in Hurricane Helene where climate change increased rainfall by 10% and wind by 11%.
The connection between global warming and the increased intensity of hurricanes is clear. Warmer oceans, higher atmospheric moisture, and rising sea levels all contribute to making these storms more powerful and destructive. Understanding this link is crucial for improving our preparedness and response to hurricanes, and for taking action to mitigate the impacts of global warming. Every degree of warming we prevent can prevent worse impacts.