Not only is it definite that sea levels are rising, but it is also clear that the level of the Chesapeake Bay is rising twice as fast as global rates, according to ESSIC professor Raghu Murtugudde.
The Associated Press published a story Monday that said U.S. Geological Survey scientists have found that the entire East Coast is particularly in danger of rising sea levels.
Murtugudde, director of the Chesapeake Bay Forecast System Project, said that part of the problem is that with every centimeter of sea level rise – the Chesapeake rises three to four millimeters every year – storms can reach several meters to hundreds of meters of additional storm surge area.
“Storms can push water much farther along with each centimeter of sea level rise – much more than you would think,” Murtugudde said. “So you’re not just losing land to sea level rise; you’re also getting additional damage from storms.”
“What happens when you get storms like hurricanes that only come every 100 years coming every 20 years instead? We need to plan for these kinds of things,” he added.
One East Coast city that is the subject of special concern regarding sea level rise is Norfolk, Va. At the southern tip of the Chesapeake, Norfolk is surrounded by water: Between the Chesapeake to the northeast, the Lafayette and Elizabeth Rivers to the west, Lake Whitehurst to the east, and Willoughby Bay to the north, Norfolk is surpassed only by New Orleans in terms of vulnerability to sea level rise.
Murtugudde said that Norfolk’s sinking land is also a prime concern. Urbanization leads to an increase in sediments flowing into water sources; this pushes the land down relative to the sea.
An entire section of the city’s website is devoted to flood awareness and mitigation. Maps on the site illustrate flood-prone areas and storm surge areas: One of them shows that the storm surge of a category 4 hurricane affects almost the entire city.
A National Wildlife Federation technical report titled “Sea Level Rise and Coastal Habitats in the Chesapeake Bay region,” states that 16-22 percent of dry lands in the Norfolk and Virginia Beach region will be lost by 2100, primarily due to widening of rivers in the region. Murtugudde added that global warming and warm, expanding waters have already increased both salinization and loss of freshwater marshes due to the intrusion of ocean water into the Bay.
The report adds that although only 3 percent of developed land would be at risk with 50 centimeters of sea level rise, 19 percent would be at risk with two meters of sea level rise.
Murtugudde said that although Norfolk is a particularly serious case, the entire East Coast is at risk.
“The whole East Coast is pretty vulnerable,” he said. “Anything sitting out there can become very vulnerable to storms. As temperatures keep warming, we will have more storms coming north. It is serious.”
In order to respond to concerns regarding sea level rise, Murtugudde said the goal should be “avoiding the unmanageable, managing the unavoidable.”
Specifically, he said the first step is to recognize the present conditions and make it known that people will be vulnerable. All construction must plan for at least the next 30 years and be built in ways that will allow adaptation to changes in sea level and storm severity.
He emphasized the importance of the issue of sea level rise, calling it a tremendous national security issue due to the threat against U.S. Navy assets such as the base at Norfolk and even against the nation’s capital due to its proximity to the Chesapeake.
The key to addressing the issue of sea level rise, Murtugudde said, is making projections and getting a good hold on how things will change. But we have to plan based on the possible outcomes of these projections too, he said.