Chesapeake Bay is a beautiful and vitally important body of water located in both Maryland and Virginia. According to an organization called CSSPAR, Chesapeake Bay could rise an additional 0.6 to 1.2 meters (two to four feet) by the end of this century. The name CSSPAR (pronounced "see-spar") stands for Chesapeake Sea Level Rise and Storm Surge: Public Awareness and Response.
Sea levels around the world are rising due to a steady increase in average temperatures. This rise in temperatures is known as global warming. It is primarily caused by the burning of fossil fuels like coal and gasoline. As average temperatures rise, polar ice from both Greenland and Antarctica is melting into the world's oceans. Historically, oceans have risen at an average rate of 12.7 to 20.3 centimeters (five to eight inches) every 100 years. They are now rising far more quickly.
Chesapeake Bay's water level is rising at an even faster rate than average, however, because the land underneath the bay is sinking. During the last ice age, glaciers pushed the land surrounding Chesapeake Bay upward. After the glaciers melted, the land slowly retreated to its original position. As the land sinks, the water in the Chesapeake Bay rises. This process is responsible for about half of the Chesapeake region's sea-level rise.
Already near Sea Level
Much of the land in the Chesapeake region already lies very near sea level. For that reason, even a small rise would have a major effect.
Researcher Sean O'Connor created maps for CSSPAR that illustrate the predicted effects of sea-level rise on the Chesapeake Bay. If sea-level rise continues at its current rate, the bay would invade the land for miles in some places. It would destroy around 167,000 acres of marshland by the year 2100. Around 1.9 million homes would be destroyed.
The Chesapeake Bay is a precious American resource. It is "the nation's estuary," O'Connor said. An estuary is an area in which freshwater rivers meet the ocean. The mix of fresh and salty ocean water creates a delicate, marshy habitat called wetlands.
Hundreds of rivers empty into the Chesapeake estuary along the shorelines of six states. Around 18 million people live in the Chesapeake region. The U.S. capital, Washington, D.C., is located near the Chesapeake.
Sea-level rise in the Chesapeake Bay will destroy the wetland habitats of many birds, fish, shellfish and plants. Human populations and structures are also at risk. In many low-lying areas, farms and homes will have to be relocated as the bay floods the land. Major cities like Baltimore will be at risk.
Acute Effects of Storms on the Region
A higher water level in the bay means stronger storm surges and higher floodwaters. A storm surge is a sudden rise in sea level caused by a major storm.
Powerful tropical storms and hurricanes formed in the Atlantic Ocean can smash into the U.S. East Coast. The low-lying Chesapeake region is at risk when one of these storms hits. Cities, towns and highways are all in danger of being flooded if the ocean surges inland.
Global warming is not just causing a rise in sea levels. It is also creating more extreme weather conditions. As global warming intensifies, storms will become more powerful and more frequent.
More intense storm surges are already hitting the Chesapeake. Scientists from CSSPAR compared a 1933 storm to a 2003 storm, Hurricane Isabel. The storms hit the same coastal area with roughly equal force. However, the storm surge from Isabel was higher than the one in 1933.
Hurricane Isabel's surge was measured at 1.8 to 2.4 meters (six to eight feet) above the normal water levels of the Chesapeake Bay. The deadly storm ripped apart buildings and wetlands. It caused millions of dollars in damage, downed thousands of trees and cut off electricity to two million people.
What would happen if a storm like Hurricane Isabel hit the Chesapeake 70 years from now? By that point, the sea will be about 0.6 meters (two feet) higher than it is now.
Flooding would be worse than anything ever seen before, CSSPAR scientists say. For instance, Isabel caused an eight-foot-high flood in Old Town Alexandria, Virginia. Add another 0.6 meters (two feet) to the bay, and the flood would be three meters (10 feet) high. Homes, hotels, roads and islands would be flooded and muddy. Much of the nation's capital would be covered in deep, muddy water.
Technology will Help Spread Information
In the future, storms will likely be much more powerful. However, O'Connor says, improved technology may reduce human deaths when such storms hit. For example, weather satellites and GPS will help people understand how strong a surge will be and how long it will last. Such technology will allow people to get out of a storm's path in time, O'Connor believes.