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A Blue View: Maryland’s Response to Sea-Level Rise

If you’re familiar with climate change, then you probably know that the resulting rapid rise in sea levels is cause for concern.

Published March 22, 2016


Two major factors influence sea-level rise: melting land ice (like glaciers or Greenland’s ice sheet) and seawater’s tendency to expand as it warms, called thermal expansion. As sea levels rise, floods and storm surges threaten coastal communities.

According to a recent report published in the journal Nature, sea-level rise has the potential to affect more than 13 million people living in the United States.

The Chesapeake Bay region is one of the highest at risk, with sea levels rising faster than any other region along the east coast. That’s because in addition to climate change, the region is also slowly sinking. That’s right—sinking.

Geologists believe that the land in this region was raised by the weight of a prehistoric ice sheet—the regions bordering the massive ice sheet, such as Washington, D.C., protruded upward. Since the ancient ice melted, the land beneath the Chesapeake Bay has slowly been settling back down.

Average global sea levels are likely to rise between one and 2.5 feet by the end of the century, but experts estimate the Chesapeake Bay’s sea-level rise could be greater than three feet.

Some regions are taking action to help combat climate change and related sea-level rise, including Maryland. The state is taking a look at the areas impacted by climate change and identifying opportunities to take proactive steps. They’re focusing on human health, agriculture, terrestrial and aquatic ecosystems, water resources and infrastructure.

Interested in the expected rate of sea-level rise in your area? Check out this interactive map.

Episode Transcript

The Greenland ice sheet is melting. Global temperatures are increasing. Sea level is rising. We've known these facts for some time now, so where's the news here? It's the pace of these changes.

From 1900 to 2010, the Greenland ice sheet lost over 9 gigatons of ice. But in the last seven years of that period, the melt has been accelerating ever more swiftly, and it has outpaced every prediction made. From 2003 to 2010, the loss of ice sheet mass more than doubled rate of the entire 20th century. The result? Greenland meltwater is gushing into the sea and global sea level is rising way too fast for comfort.

How fast? According to the Intergovernmental Panel on Climate Change, sea levels could rise by more than 3 feet by the end of this century. The US Army Corps of Engineers, an agency not known for wild-eyed hypotheses, projects a rise of up to 5 feet, and NOAA, the National Oceanic and Atmospheric Administration, predicts a range of up to 6.5 feet.

Some scientists have estimated if the entire Greenland ice sheet melts away, it could raise sea levels by more than 20 feet...scary enough, but for the fact that many believe these projections may be too conservative.

Coastal countries around the world are scrambling to prepare for this possible worst-case scenario. And here in the US, Maryland is one of the states most vulnerable to sea level rise, along with Virginia, Delaware, Louisiana and Florida. With our 3,100 miles of low-lying tidal shoreline along the Chesapeake Bay and Atlantic Ocean, over 250,000 acres of rural and urban lands are at risk, for they are all less 5 feet above the high-tide line.

Sea level in the Baltimore-Washington metro area is rising faster than any other region along the East Coast.

A storm surge like Superstorm Sandy, were it to occur at high tide, could lead to heavy flooding in Baltimore, Annapolis, St. Michaels and the entire lower half of the Delmarva Peninsula. At this stage, experts believe the pace of sea level rise in the Chesapeake is about 4 millimeters per year…but as I’ve already noted, this is a feedback loop, where the pace of change grows year by year.

We are in a race with time, and the imperative is to ADAPT. We need new building codes that require homes and businesses to be built ever higher above the flood plain. Coastal resiliency is the new law of the land. We need to encourage state and local governments to craft laws and codes that limit development on vulnerable lands and encourage people living there to move up or move out.

The Environmental Protection Agency is not harboring any false hopes that this problem will go away…In its analysis of sea level rise, the EPA is telling us that we should not expect to be able to hold back the sea. Adaptation and mitigation are more realistic pathways.

Maryland’s history is replete with examples of towns lost to the relentless tides. Today, the Eastern Shore town of Crisfield, once called "the seafood capital of the world," is at great risk. Saltwater is encroaching, trees are dying, and people are moving away. One estimate predicts that, by the end of this century, more than half of Dorchester County will be underwater.

Sea-level rise will affect human health, agriculture, population growth and infrastructure. A conservative estimate is that globally, one hundred million people live within 3 feet of mean high tide, and another hundred million or so live within 6 feet of it. So we’re not alone here in the Chesapeake region…we have plenty of company. What’s important is that we do in the next decade will set the stage for the rest of the century… And one thing is certain: you can’t turn back the tide.

You can learn more about sea level rise and how Maryland plans to adapt—plus, view a model of sea level rise at your own address— by going to

A Blue View is produced for WYPR by the National Aquarium, whose mission is to inspire conservation of the world’s aquatic treasures. For the National Aquarium, I’m John Racanelli.

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