National parks, especially in the Southeast, are bearing the brunt of intensifying weather events.

Beryl. Milton. Rafael. Kirk. Helene. The first thing these names have in common is that they were among the most destructive hurricanes of the 2024 season. The second thing is that every single one of them had higher wind speeds than they would have had without the existence of climate change, according to a recently published scientific study.

Authored by the nonprofit Climate Central organization in the peer-reviewed journal Environmental Research: Climate, climate change increased maximum wind speeds for every Atlantic hurricane in 2024, continuing an alarming trend. The study also showed that, for nearly all (84 percent) Atlantic hurricanes over the past five years, maximum wind speeds intensified by an average of more than 18 miles per hour, according to the researchers. 

“Every hurricane in 2024 was stronger than it would have been 100 years ago,” Dr. Daniel Gilford, a climate scientist at Climate Central and lead author of the study, said in a statement on the report’s release. Using a methodology known as attribution science, Gilford and his peers further concluded that two of these hurricanes—Beryl and Milton—were pushed into Category 5 territory, which would have been unlikely without climate-change-related ocean warming. 

For national parks, especially those in the Southeast, this could mean that their ability to withstand the impacts of extreme weather events—storm surge, downed trees, destruction of cultural resources, dune erosion, and more—will be increasingly compromised. And their ability to rebound could be tested more than ever before.

Rapid Intensification

Located on a finger of land near Bradenton and Longboat Key, Florida, De Soto National Memorial is a small but significant national park unit that commemorates the 1539 landing of European explorer Hernando de Soto. It is one of dozens of lesser-known national park units in the Southeast, receiving about 140,000 visitors a year. But this past fall the park was slammed by the one-two punch of hurricanes Helene and Milton. As of mid-January, the park remained completely closed, as park staff work to assess, clean up, and repair damage to facilities and park trails.

“Helene was a hundred miles offshore from us, but it pushed so much water,” says Daniel Stephens, the park’s lead ranger. “We took in about six to seven feet of water through the park. Every building in the park, except for our headquarters building, was flooded and took in water.”

Hurricane Helene's storm surge flooded most of De Soto National Memorial's buildings, which endured more damage from Hurricane Milton. / NPS

Even months after the fact, national parks are still recovering from the widespread damage caused by the 2024 hurricane season. In late September, Hurricane Helene caused such a broad swath of destruction that portions of Great Smoky Mountains National Park, the Blue Ridge Parkway, and the Appalachian National Scenic Trail were closed for many weeks, and some areas remain closed as of this writing, three months later. Several national parks in South Carolina, including Cowpens National Battlefield and Kings Mountain National Historical Park, are also still partially closed due to Helene impacts.

Making landfall on the Gulf Coast of Florida just two weeks after Helene, Hurricane Milton caused significant damage across the state, including downed trees, torn-up boardwalks, erosion, and overwashed roads at Cape Canaveral National Seashore.  

This month, the World Meteorological Organization announced that 2024 was the hottest year in the planet's recorded history, a trend likely to continue fueling natural disasters such as storms and wildfires. Since 1895, human-caused climate change has heated the national parks at double the rate of the country as a whole, according to research led by Dr. Patrick Gonzalez, formerly the chief climate scientist for the Park Service and now a professor at University of California-Berkeley. Gonzalez was the lead author on a 2018 study that was the first spatial analysis of historical and projected temperature and precipitation across the entire park system. 

"Human-caused climate change has intensified extreme storms, increasing rainfall one-third on the heaviest storm days, since 1958," says Gonzalez. "If we don’t cut the carbon pollution from cars, power plants, and other human sources that causes climate change, continued heating could increase the frequency of very strong hurricanes globally 20 percent by 2100 AD, increasing risks of damage to Canaveral, Jean Lafitte National Historical Park and Preserve, Louisiana, and other southeastern U.S. national parks.” (Requests for comment from the NPS climate office were referred to the agency's main communications department, which has not responded.)

It's not just the fact that storms are getting more intense, climate scientists say, but they are exhibiting a phenomenon known as rapid intensification. This is often defined as an increase in a tropical cyclone’s maximum sustained winds of at least 30 knots (35 mph) over a 24-hour period (often lasting even longer). Scientists say this is directly tied to warming ocean temperatures, which means more evaporated water in the air, which is the energy that fuels storms. All of 2024’s Atlantic hurricanes increased in intensity by 9 to 28 mph, and seven experienced rapid intensification. 

“Climate change is making extreme weather more frequent and more intense,” says Lauren Casey, a meteorologist with Climate Central. “We are heating up the atmosphere, and greenhouse gases trap that heat underneath. We’re adding more energy to our system. For every one-degree temperature increase, the atmosphere can hold 4 percent more water vapor. When we get those triggers and we get rainfall, it’s coming down heavier, and it’s coming down faster.” 

Rapid intensification of storms is also more difficult to forecast, which means that people, wildlife, and ecosystems are more likely to be taken by surprise, leading to more damage, higher recovery costs, and longer recovery periods. According to Climate Central, since 1980, 70 percent of the 63 tropical cyclones that caused at least $1 billion in damage in the United States underwent rapid intensification.

“Rapid intensification with tropical systems is becoming so common,” Casey says. “We are seeing and are going to see more high-end hurricanes, category 4s and 5s.”

Shifting Threats

Aside from expected impacts of major storms, such as flooding, erosion, and downed trees, another phenomenon that climate scientists are watching is the steady geographic shift of “Tornado Alley,” traditionally considered to be centered on the Great Plains. As the climate changes, so is the general location of tornado outbreaks, including those connected with hurricanes, which are increasingly developing across the more populated Midwest and South.

According to a 2024 study published in The Journal of Applied Meteorology and Climatology, between 1951 and 2020 tornadoes in the western United States have decreased 25 percent  while tornadoes in the eastern U.S. increased 12 percent. Although tornadoes are not uncommon with hurricanes, recent hurricanes have spawned record numbers of twisters.

Two 2024 storms, Beryl and Milton, cracked the top 15 list of most confirmed tornadoes associated with hurricanes, with 68 and 46, respectively. One Milton-related tornado touched down at Cocoa Beach, to the south of Cape Canaveral. And the outer bands from Helene spawned a tornado in the Blue Ridge Parkway town of Blowing Rock, North Carolina, two days ahead of the storm itself.

“Typically, we don't have tornadoes in the mountains,” Charles Hardin, director of the Blowing Rock Chamber of Commerce, said in October shortly after the storm hit. “It didn't hurt any buildings, but it took down a lot of trees and twisted power lines.”

For national parks along the Atlantic coast, in places like Everglades National Park and Fort Pulaski National Monument, increasingly powerful storms also bring more saltwater intrusion into freshwater areas, which disrupts native vegetation growth, releases pollutants from agricultural soils, degrades drinking water quality, and damages cultural and archaeological resources.

“When saltwater comes farther in, it completely damages the ecosystem,” Casey says. “We’re disrupting this delicate balance of this ecosystem in these national parks.”

Preparing for More

Across the system, the National Park Service has been working to assess park vulnerability to various threats and to build resiliency against extreme weather events. At Fort Pulaski near Savannah, Georgia, for example, NPS and the U.S. Army Corps of Engineers recently collaborated on a drainage project to mitigate the extensive flooding and saltwater intrusion the monument has suffered in recent years. The park is supported by a ditch and dyke system that dates to the 1800s. Focusing on Ditch #5, the project includes the installation of a drainage pipe flap that will help prevent saltwater incursion by staying closed when saltwater is flowing in, but will allow water to flow out as needed.

NPS and the U.S. Army Corps of Engineers collaborated on a drainage project at Fort Pulaski National Monument to help protect it from storms / USACE

And at Great Smoky Mountains National Park, researchers are continuing to monitor rainfall levels at various elevations and locations to help determine how water moves through the park and help predict landslides and flooding. Dr. Doug Miller, a professor of atmospheric sciences at University of North Carolina-Asheville who has held a research permit in the park for 20 years, has been monitoring a network of 12 rain gauges within the park, part of a 32-gauge network in the Pigeon River basin. "What we find is useful to lots of other disciplines is that water is one of those inputs that determines the health of that ecosystem," Miller says. "For management and safey, it's all about landslides and flash flooding." 

Another phenomenon Miller is studying is atmospheric rivers, channels of water vapor that move from the tropics or subtropics and can cause heavy rainfall over land. As with other storms, warmer ocean temperatures mean potentially more loaded atmospheric rivers and possibly more landslides and flooding. Miller says that he and other scientists will continue to examine data collected from Hurricane Helene and conduct further research this year. 

Despite such efforts, protecting national parks against worsening storms often feels like a race against time, especially as storms become more difficult to forecast because of warming oceans and rapid intensification.

Climate Central, for its part, is planning to release a new study focused on national parks in the spring, and scientists will continue to develop attribution tools so they can better assess the extent to which climate change is making things worse, Lauren Casey says.

“The threats [to the national parks] are myriad and depend on location,” she adds. “Sea level rise is going to continue to threaten our coast, hot sea surface temperatures contribute to coral bleaching, and then we have rainfall and flooding [like we had] in Appalachia. The thing with climate change is there are cascading impacts.”