Thursday, September 12, 2013

Study measures mountaintop removal's effect on the Central Appalachian landscape

"To meet current U.S. coal demand through surface mining, an area of the Central Appalachians the size of Washington, D.C., would need to be mined every 81 days," says a press release from Duke University(Google Earth image) Researchers at Duke, Kent State University and the Cary Institute for Ecosystem Studies conducted a study that calculates the true cost of a ton of mountaintop-removal coal, finding that "a one-year supply of coal would require converting about 310 square miles of the region’s mountains into surface mines. This would pollute about 2,300 kilometers of Appalachian streams, and cause the loss of enough carbon sequestration by disturbed trees and soils to offset all the greenhouse gases produced that year by 33,600 average U.S. single-family homes." The study was published in PLOS One, the journal of the Public Library of Science.

The study’s authors "used satellite images and historical county-by-county coal production data to measure the total amount of land area mined and coal removed in the Central Appalachian coalfield between 1985 and 2005," states the press release. "They found that cumulative coal production during the 20-year period totaled 1.93 billion tons, or about two years’ worth of current U.S. coal demand. To access the coal, nearly 2,000 square kilometers of land was mined – an area similar in size to the Great Smoky Mountains National Park."

Emily S. Bernhardt, associate professor of biogeochemistry at Duke, said, “Given 11,500 tons of coal was produced for every hectare of land disturbed, we estimate 0.25 centimeters of stream length was impaired and 193 grams of potential carbon sequestration was lost for every ton of coal extracted. Based on the average carbon sequestration potential of formerly forested mine sites that have been reclaimed into predominantly grassland ecosystems, we calculate it would take around 5,000 years for any given hectare of reclaimed mine land to capture the same amount of carbon that is released when the coal extracted from it is burned for energy."

Brian D. Lutz, assistant professor of biogeochemistry at Kent State, said, “Even on those rare former surface mines where forest regrowth is achieved, it would still take about 2,150 years for the carbon sequestration deficit to be erased." (Read more)

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