A vast number of coastal cities in the U.S. would be submerged if sea levels rise 10 feet, according to a map by the National Oceanic and Atmospheric Administration (NOAA).
A 10-foot sea level rise would be "catastrophic" for America, Randall Parkinson, a coastal geologist and professor at Florida International University, told Newsweek.
Why It Matters
Rising sea levels pose multiple risks, not only the flooding of coastal towns but also damage to sites that store certain hazards, as well as possible contamination of drinking water sources.
A recent survey found there are 5,500 sites that store, emit or handle sewage, trash, oil, gas and other hazards that could face coastal flooding by 2100.
The researchers also found that more than half the sites are projected to face flood risk much sooner—as soon as 2050—and low-income, communities of color and other marginalized groups are the most at risk.
On the West Coast, the NOAA map shows that Washington would be affected, with cities like Seattle, Aberdeen and Port Townsend partly submerged, as well as strips of Oregon's coastline becoming severely flooded.
Many coastal cities in California would also be underwater too, like Crescent City, and the outskirts of cities like San Francisco, Oakland, Long Beach and San Diego.
On the East coast, large parts of the coastline of Maine would be submerged, and cities in Massachusetts would also be affected like Boston, Gloucester, Salem and Quincy.
Large proportions of Rhode Island would be affected, with the rise in sea levels flooding cities like Warwick and Newport. New York City would also be partially flooded, with Manhattan, Brooklyn, Queens and Staten Island all underwater in some areas.
Atlantic City, in New Jersey, would be submerged in water, as would Ocean City and a number of others.
The projection on the map that indicates submersion risk also spills right through Maryland, reaching as far as Baltimore, while also creeping into Virginia, partially covering cities like Newport News and Virginia Beach in water.
A significant proportion of North Carolina would also become submerged, impacting cities like New Bern, Greenville and Jacksonville, while in South Carolina cities like Charleston, would be covered in sea water.
Georgia would also be affected, with cities like Georgetown, Darien, Brunswick and many others flooded, and Florida's famous coastline would be dramatically changed.
Cities in the state like Jacksonville, Melbourne, Port St Lucie, Fort Lauderdale, Hollywood, Naples, Venice, Sarasota, Tampa and St. Petersburg, as well as many of its beaches, such as Miami Beach, Barefoot Beach, Fort Myers Beach would all be at risk of submersion.
Moving further south around America's coastline, while New Orleans in Louisiana would be safe, much of the area surrounding it would be completely submerged.
In Texas, Texas City, Port Lavaca, Rockport, Corpus Christi, and Portland would all be flooded with sea water.
The Impacts of a 10-Foot Sea Level Rise
A 10-foot sea level rise would therefore have dramatic impacts on the country's coastline, and many of America's coastal cities would be completely destroyed.
"Not only would everything above ground be submerged, but everything that is under ground as well and sooner—that includes stormwater and sewer conveyance systems that may rely on gravity flow to reach their destination, for example a treatment facility," Parkinson told Newsweek.
He added that sea level rise also affects groundwater—one of the country's major sources of drinking water—because as sea level rises, "so too does the groundwater table."
This means that areas located "more distant from the coastline may experience nuisance or permanent freshwater flooding well before they are affected by sea level rise," he said.
Salt water intrusion could also occur, Parkinson said, a "process that salinizes groundwater well inland of the advancing shoreline."
"This can impact shallow drinking water or irrigation wells, and catalyze corrosion of the structural elements of buildings, roads or culverts," he said.
What's the Likelihood of a 10-Foot Sea Level Rise?
Parkinson told Newsweek that he thought a 7-foot sea level rise is "very likely" by 2100, and that a 10-foot sea level rise above present levels "will surely follow, but about 20 years later."
There are a number of factors contributing to the rising sea level. One is the thermal expansion of sea water, Parkinson said, a result of global warming, and another factor is that melting land glaciers are adding new water to the ocean and increasing its volume.
"Towards the end of this century, the input from glacial meltwater is expected to accelerate," he said.
Rising atmospheric temperatures, caused by increasing carbon dioxide levels, are playing a notable role in the rising of sea levels, and so the "most important thing that can be done is to reduce carbon dioxide emissions," Parkinson said.
Although, he added that "the persistence of this gas in the atmosphere is measured in centuries, so we won’t be going back to the way things were even if emissions were ended today."
A reduction in emissions are therefore intended to limit the "deleterious effects of a warming climate on future generations," he said, which includes sea level rise, but also all the other climate-related impacts.
Parkinson said coastal planners will now need to "shift away from the protect and defend strategies currently employed to ‘combat’ sea level rise and event-driven coastal flooding."
Instead, they need to focus on "managed migration strategy that includes the abandonment of high risk or frequently flooded areas that could be replaced by natural areas that buffer or protect the more landward built environment from the effects of sea level rise and storm surge," he said.
Newsweek