Climate Fact: Under the Sea
More heat in the Earth system leads to sea level rise through two main processes: thermal expansion and the melting of glacial (land) ice. Over the past 100 years, global sea levels have been rising at a rate of 0.7 inches per decade. Sea level rise impacts include increased coastal erosion, submergence of land surfaces and salt-water intrusion into coastal aquifers, which supply water to some of America’s most populated areas. In Maryland, sea levels around the Chesapeake Bay have been rising at a higher rate compared to global measurements; here, the rate of sea level rise during the 20th century was 1.38 inches per decade. This higher rate is due to local land subsidence – as the global sea level has been rising, the land mass has also been sinking, which increases the rate at which the sea encroaches onto the land. This rapid rise has led to impacts such as the submergence of land in Blackwater Wildlife Refuge. About 8,000 acres of Blackwater Wildlife Refuge that were above water in 1930 are now under the sea. This means that about 150 acres of land are lost to the ocean each year.
Seasons: Winter, Spring, Summer, Fall
Sources: United States. NOAA. National climate data center. “Global warming frequently asked questions: is sea level rising?” NOAA. Web. 7 Sept. 2009
