The price tag on protecting our beaches and coastal properties from rising seas could be tremendous.
Around the world, harbor-masters have long noted that sea-level is rising. Until recently, it was rising at about 1 mm each year. That’s a pretty small value, likely derived from continued melting of the polar ice sheets that began at the end of the last glacial period.
But more recent measurements from NASA satellites have shown since the 1990s, sea level rise has accelerated to more than 3 mm a year. That’s nearly 3 feet in the life-time of young Americans.
Why the increase? There are many signs that the Earth is warming up. And when ocean water warms, it expands. Greenland and Antarctica are home to the world’s largest ice sheets. As these land-based ice sheets melt, their water enters the ocean and contributes to sea-level rise.
A rise of three feet of sea level will flood many major U.S. cities, and most of southern Florida, requiring enormous expense to protect property, beaches, and coastal fisheries.
“We are capable of engineering sea walls for the immediate future, but the price we end up paying in the loss of the beach in front of the sea wall,” notes Orrin Pilkey, a coastal geologist at Duke University. “For a while we can hold back the rising sea, but not for very long, until it becomes economically impossible.”
Coastal fisheries will suffer when estuaries and coastal wetlands disappear with flooding. These habitats are vital to fish breeding. And we can be certain that coastal landowners will ask for disaster relief from storm-surges. Even the Navy is concerned about the impact of rising sea level. They are currently strategizing was to build new harbors.
Web Extra
Orin Pilkey explains how high sea level means stronger waves.
[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2012/01/SeaLevel-Pilkeyweb.mp3|titles=SeaLevel-Pilkeyweb]Photo credit: mikeyskatie/via Flickr