Posted on October 13, 2021
If another Hurricane Isabel hit the Chesapeake Bay area a few decades from now, it could affect at least a million more people and cause $6 billion more in damage than when it landed in 2003, new research suggests.
By the century’s end, even storms we consider weak today will have the impact of stronger storms, according to the recent study from the nonprofit Resources for the Future, which conducts economic research on environmental issues.
“People talk about what climate change is going to do to storm frequency and intensity,” said Margaret Walls, a senior fellow at the nonprofit and co-author of the study. “But what we’re showing is it doesn’t matter if they get worse. They’re going to have worse impacts because of sea level rise.”
There’s plenty of research looking at the effects of sea level rise, particularly in flood-prone southeastern Virginia. But Walls said her team wanted to home in on storm surge.
Sea level rise is going to change the landscape, Walls said. Some land will be open water, some will turn marshier. In general, wetlands will slowly migrate inland, she said.
That changes the way storm surge will affect people and properties.
For the study, published recently in the Natural Hazards Review journal, researchers combined sea level rise and wetland loss, along with detailed property data to assess potential damages.
The Chesapeake Bay region has been studied less than say, the Gulf Coast, when it comes to hurricanes, Walls said.
The group used data from two storms that hit the region: Hurricane Dennis in 1999 and Hurricane Isabel in 2003.
They considered Dennis a weaker storm, with maximum winds of just over 100 mph, while Isabel’s ferocity brought in 167 mph gusts.
The team then simulated the storm surge those hurricanes would cause under future scenarios. The range included the minimum amount sea levels are expected to rise, the maximum, and both in combination with wetland loss.
The researchers wrote that Chesapeake, Virginia Beach, Norfolk and Hampton are most at risk, along with Anne Arundel County in Maryland.
Under the highest level of sea level rise, they found that residential property damage from an Isabel-style storm could reach $9.3 billion, more than 13 times the same storm in current conditions.
But the amount of change was even greater for weaker storms, Walls said. A future Dennis could cause $5.8 billion in damage — about 84 times what would happen in current conditions.
In the Chesapeake Bay region, 6,777 properties would currently flood in a weaker storm, and 40,553 in a stronger, the study estimated. With sea level rise, those numbers increase to 218,319 and 300,282.
Take Virginia Beach. Under an Isabel-level storm combined with the maximum sea level rise, the city would see an additional $1.64 billion in property damage over current conditions.
Loss or changes to wetlands can further exacerbate property damage, the authors wrote.
Walls said she wasn’t necessarily surprised by the research, but it’s a way to quantify what’s coming.
Leaders need to think about the way we use land, she said. That means adapting to environmental changes, some of which are inevitable, but the worst of which can be slowed by reducing the greenhouse gases we burn.
There are ways to conserve wetlands or improve infrastructure to protect property, she said. And some may need to move out of nature’s way.