In November, Hurricane Eta made landfall in Central America. It caused destruction from Panama to Florida. Two weeks later, Hurricane Iota arrived. It was more powerful. It rained on places that were already flooded. Juan Orlando Hernández is president of Honduras. He called Iota a “bomb” that would leave the region in tatters.
According to the National Oceanic and Atmospheric Administration (NOAA), the 2020 Atlantic hurricane season was the most active on record. Iota was the 30th named storm to brew in the Atlantic since May. It was the 13th to become a full-blown hurricane.
Scientists say climate change is to blame. They don’t know if it’s causing more storms. But data seems to show that it’s making storms stronger.
James P. Kossin works for the NOAA. He says the increase in greenhouse-gas emissions is changing how storms behave. “These storms have a human fingerprint on them,” he told TIME for Kids.
A hurricane begins in the ocean. It draws its energy from ocean air. The planet’s oceans are warming. Warmer water provides a storm with more energy. That means higher winds. It also means heavier rain. (See “Hurricanes 101.”)
Increased energy is causing hurricanes to get stronger faster. In August, Laura changed from a tropical storm to a strong hurricane in about a day. It slammed into Texas and Louisiana. Winds reached 150 miles per hour (mph). Laura’s storm surge—a wall of ocean water mainly caused by wind—reached 17 feet in places.
Hurricanes are also sticking around longer. So they do more damage. Westerly winds constantly blow around the planet. But they are slowing because of rising temperatures. That causes slow-moving storms. Hurricane Harvey flooded parts of Texas in 2017. “That storm was devastating because it didn’t move,” Kossin says. “It just sat there.”
Storms don’t affect everyone equally, Dereka Carroll-Smith says. She’s a scientist at the National Institute of Standards and Technology. She analyzes data on communities that are most affected by hurricanes. This helps cities plan ahead.
Carroll-Smith says areas with a high number of elderly people who can’t easily leave may need one emergency plan. A different plan might be needed where many people live in mobile homes. Recently, evacuations were complicated by the pandemic. Shelters couldn’t hold the usual number of people because of social distancing.
“Intense storms are going to be devastating to everyone,” Carroll-Smith says, “unless we make preparations now.”
According to Kossin, reducing greenhouse gases is the first step. “We can stop making it worse. Then we can [start] adapting to the new climate we’re in.”
A hurricane is a mass of clouds and thunderstorms. It rotates around an “eye,” or center. Think of a hurricane as a giant engine. Warm, moist air is its fuel. There’s plenty of that in the Atlantic during hurricane season.
Winds must reach 74 mph before a tropical storm is called a hurricane. Then it is rated on a scale of 1 to 5. The rating depends on wind speed. A Category 5 storm churns at 157 mph or more. It can destroy homes. It can make an area unlivable for weeks or even months.