The Carbon Footprint of Mountaintop Mining

Mountaintop removal is without a doubt the world's worst coal mining -- responsible for landscape destruction, habitat loss and water pollution throughout Appalachia.  As if all that weren't bad enough, new research suggests that the global warming pollution from conventional (dirty) coal-fired power plants are up to 17% higher when greenhouse gas emissions relating to mountaintop mining operations are factored in.

That's according to a new study -- Terrestrial Carbon Disturbance from Mountaintop Mining Increases Lifecycle Emission for Clean Coal -- by two civil engineering professors, James Fox of the University of Kentucky and J. Elliott Campbell of the University of California.  The crux of their analysis dealt with the life-cycle components of coal production, such as emissions during mining, refinement and coal transportation. 

Using data from the U.S. Department of Energy, Fox and Campbell found that from 1997 to 2006, coal accounted for 33% per year of the total energy produced in the United States.  Meanwhile, coal consumption accounted for 36% of the carbon pollution produced in the U.S. due to the burning of fossil fuels.  Thus, coal is both a primary energy source and contributor to global warming pollution. 

They noted that one aspect of coal production that has received less attention is "the redistribution and loss of terrestrial carbon during surface or mountaintop coal mining methods."  They focused their study on the region of Appalachia covering southern West Virginia, eastern Kentucky, southwestern Virginia, and portions of east Tennessee -- in other words, ground zero for mountaintop mining.  (They define this method generally as surface mining, including mountaintop removal, steep-slope mining, contour mining and area mining.)  Using published data on factors such as forest and soil carbon, they calculated the carbon emitted when companies cut down trees and sheer off mountaintops to access that coal. 

Through this strip mining method, some 500 mountaintops have been destroyed and nearly 2,000 miles of valley streams have been buried under tons of rubble.  In addition, more than one million acres of forest have been clearcut.  In fact, according to the research by Fox and Campbell, over the past two decades some 6.8% of forests have been removed in Appalachia to produce 23.3% of the coal in the United States.  

Bear in mind that the forests of southern Appalachia represent the most biologically diverse temperate deciduous forests in the world.  Mountaintop mining is destroying these forests at an alarming rate.  As I cite in my own research paper, the U.S. Environmental Protection Agency (EPA) estimates that at current rates of deforestation from mountaintop removal, the total forest loss by 2012 would be 1,408,372 acres (or 2,200 square miles).  The loss of forest cover this size means the loss of 3.14 million tons of carbon dioxide sequestration annually.  Fox and Campbell confirm in their study that "forest disturbance" from mountaintop mining has resulted in a drastic reduction in natural sequestration (or storage) of carbon.  One reason, they note, is that the trees cleared for the mining are typically burned on-site (instead of harvested), resulting in higher carbon emissions.

They also looked at regrowth on post-mined sites to determine net carbon emissions.  They estimate that "reclaimed areas in the Appalachian coal belt show regrowth of only 3% of nonsoil carbon after 15 years."  However, they note that so-called carbon recovery may be even lower because only 2% of land disturbed by coal mining in the United States has been reclaimed -- and existing reclamation in Appalachia "has focused on erosion prevention and bankfill stability and not reclamation with trees."  To make matters worse, the natural sequestration lost due to wiping out forests means a net increase in carbon emissions.  Finally, after mountaintop mining takes place, the vegetation and soil are replaced by compacted mining spoil, which inhibits plant growth and also contains "high amounts of coal fragments" that in turn emit more global warming pollution. 

All told, their research concluded that land disturbance associated with mountaintop minining in southern Appalachia increases global warming pollution by 2–12%; those figures increase to 7–17% if greenhouse gas emissions produced during coal extraction and transport are included.

So, among the many environmental problems caused by mountaintop mining, the loss of Appalachian forests decreases natural sequestration of carbon, thereby exacerbating climate change.