Why Are Hurricanes Getting Stronger?

Written By Teacher: Liz Ransom

As a High School Spanish teacher and student newspaper advisor, Liz has taught for over 20 years and has served as World Languages Department Chair and K-6 summer camp activities leader. She has worked in Ohio, Maine, New Jersey, Maryland, and Chile.

 Hurricanes frequently make headlines and impact the lives of many students. Teaching about hurricanes can help students stay safe and introduce them to climate solutions. Elementary teachers can read their class the ebook Prepare with Pedro! Hurricane, available in both English and Spanish. Older students can develop social-emotional skills with the lesson Personal Narrative Writing: Severe Weather, or explore real-world mitigation strategies through the case studies in the resource Naturally Resilient Communities.

Written By: MIT Environmental Solutions Initiative

The MIT Climate Change Engagement Program, a part of MIT Climate HQ, provides the public with nonpartisan, easy-to-understand, and scientifically-grounded information on climate change and its solutions.

Hurricanes are intense tropical cyclones. These storms are becoming stronger as climate change warms the oceans. (The term ‘hurricane’ is actually a regional word for tropical cyclones of a certain intensity that form over the North Atlantic and eastern North Pacific Oceans. But here we will use the term to refer to all such tropical cyclones worldwide.)

A hurricane begins as a cluster of rain showers over warm tropical oceans. As air rises in these showers, more air rushes in along the sea surface to take its place. As more air gets pulled into the storm, it starts to spin around a low-pressure area at its center. This creates a feedback loop: as the wind blows harder, more warm seawater evaporates, drawing heat from the ocean. If the storm winds reach 74 miles per hour, the storm becomes a hurricane.

Stronger hurricanes

By warming the oceans, climate change is not creating more hurricanes, but it is making hurricanes stronger. That’s because warmer seawater supplies more heat to a hurricane, increasing its wind speed. Experts class hurricanes in 5 categories, with category 1 being the weakest and 5 the strongest. Since 1979, climate change has increased the risk that a storm will develop into a ‘major’ hurricane—at least category 3, with winds over 110 mph—by around 5% every ten years.

Climate change also means that hurricanes are causing more flooding. This is partly because hurricanes bring more rain than they used to: the warmer air of today’s climate holds more water vapor. It’s also because storm surges, the deadliest part of a hurricane, are getting worse. A storm surge is a rise of water created by wind from a hurricane. As climate change raises sea levels around the world, storm surges have a head start in flooding the coast. As a result, storm surges are becoming higher, penetrating further inland, and causing more damage.