Wednesday, January 27, 2010
Can We Stop the Rise of Sea Levels?
Sea levels have been rising for the past few decades, most due to global warming which is caused by the production of greenhouse gases, as we all already know. On average, the oceans are about 6.3 inches higher now than they were in 1930. The main cause is the expansion and therefore warming of sea water, from the melting caps and glaciers.
A new study has shown that reservoirs play an important role in the sea levels rising. Rather than adding to the problem, they are reversing it by storing more water on land. Reservoirs have prevented a total of about 1.2 inches of seal level rise since 1930. Without dams, the ocean would be 30 percent higher than it is today, according to a researcher from the National Central University of Taiwan.
Researchers tallied up the water stored behind the nearly 30,000 dams built worldwide. It was estimated that human-made reservoirs can store on average about 2,600 cubic miles of water. That’s nearly as much as Lake Superior holds. The water underneath the reservoirs also soaks into the ground, adding to the amount of water locked up on land.
http://news.nationalgeographic.com/news/2008/03/080313-dams-water.html
Greenland and Antarctica together comprise nearly 99 percent of the earth’s landlocked ice. These two polar landmasses contain enough frozen water to raise sea levels some 80 meters. Even if only 10 percent of this ice melted, it would flood the world’s coasts at those comparable to those seen in pos-Katrina New Orleans. A scenario that glaciologist and climate scientists are piecing together is that rather than slowly but steadily melting, the ice sheets could break apart into massive chunks.
http://www.dailygalaxy.com/my_weblog/2008/01/global-warming.html
Friday, January 8, 2010
Rising Waters along the East Coast
Sea-level rise along the Atlantic Coast of the United States was 2 millimeters faster in the 20th century than at any time in the past 4,000 years. Land in this area is being lost because of the huge weight of the melting ice sheets during the last glacial period. The coast-lines of New Jersey, Delaware and Maryland are sinking twice as fast as areas north and south of these locations. The subsiding of the coast-line increases sea level rise and eventually will lead to shoreline erosion and a loss of wetlands. This causes a huge threat to coastal populations.
"Researchers have come to a universal agreement that sea level will rise as a result of global warming but by how much, when and where it will have the most effect is unclear" said Ben Horton, assistant professor in the Department of Earth and Environmental Science at Penn.
National Resources Council of Maine (NRCM) have shown that coastal businesses, homes, wildlife habitat, transportation systems, and some of our states most treasured places are highly vulnerable to sea-level rise. The 20 communities "most at risk" range from York and Kennebunkport to Jonesport and Beals. These places could suffer in the loss of up to 30% of a towns land and cause millions dollars worth of damage to property and infrastructure. If global warming continues unabated, then portions of Maine’s coastline will be forever changed.
"Researchers have come to a universal agreement that sea level will rise as a result of global warming but by how much, when and where it will have the most effect is unclear" said Ben Horton, assistant professor in the Department of Earth and Environmental Science at Penn.
National Resources Council of Maine (NRCM) have shown that coastal businesses, homes, wildlife habitat, transportation systems, and some of our states most treasured places are highly vulnerable to sea-level rise. The 20 communities "most at risk" range from York and Kennebunkport to Jonesport and Beals. These places could suffer in the loss of up to 30% of a towns land and cause millions dollars worth of damage to property and infrastructure. If global warming continues unabated, then portions of Maine’s coastline will be forever changed.
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