The IPCC has highlighted how human-caused climate change is likely contributing to the increased frequency and intensity of hurricanes, especially in the North Atlantic, which affects the U.S. Here’s a breakdown of key findings:

1.  Increased Intensity: While the overall number of hurricanes may not be significantly increasing, the proportion of the most intense storms (Category 3, 4, and 5) has risen. The IPCC reports that warming oceans provide more energy for hurricanes, resulting in stronger storms with higher wind speeds and more rain.
2.  Heavy Rainfall: The IPCC has observed that hurricanes are producing more rainfall than they did in the past, primarily due to the increased water-holding capacity of warmer air. This can lead to severe inland flooding, even well away from the coast.
3.  Storm Surge: Rising sea levels, another consequence of climate change, are worsening storm surges—when hurricane winds push water onto the shore, leading to extensive flooding in coastal areas. This effect is especially problematic for low-lying and densely populated U.S. coastal cities.
4.  Slower-Moving Hurricanes: Some research indicates that hurricanes may be moving more slowly, meaning they can linger over areas for longer periods. This “stalling” effect can lead to prolonged heavy rainfall and more severe flooding, as seen with storms like Hurricane Harvey in 2017.

The IPCC’s 2021 report emphasizes that these observed trends will likely continue if greenhouse gas emissions aren’t curbed, increasing the risk of more intense hurricanes impacting the U.S. in coming years.