Fracking, Shale Gas And Health Effects

Rarely does a new form of energy - shale gas - have such a dizzying range of potential impacts, good and bad. It could significantly increase America's level of energy independence and help transition us to a lower-carbon future, but one of its major components, methane, is a highly potent greenhouse gas.

As the journal Nature has reported, research teams continue to find that methane leaks resulting from the natural gas extraction process pose significant environmental problems. That the United States has large deposits of shale gas is a blessing for consumers, but exploiting them could have significant environmental and health impacts, including air and water pollution as well as long-term risks such as cancer and respiratory illnesses. Even earthquakes have been reported.

Part of the risk from shale gas comes from how it's extracted: Hydraulic fracturing - better known as fracking - involves drilling down vertically through hundreds of feet of rock and then horizontally through the shale bed. Millions of gallons of rock, sand and chemicals are then pumped down under high pressure to "frack" the shale bed, releasing the natural gas trapped within it. But in drilling down to the deposits, wells often pass through aquifers that provide water to communities, plants and wildlife on the surface. Leakage of shale gas into water supplies isn't supposed to happen, but reports may indicate otherwise.

And while the surface impacts of natural-gas extraction are nothing compared to, say, mountaintop removal coal mining, they can be considerable, and deposits' location frequently magnifies the problem - for example, the Barnet Shale, one of the richest in the U.S., underlies the entire Dallas-Fort Worth metropolitan area. Residents often have little say over how gas wells are run, even those on their own property, and truck traffic can be considerable as water is trucked in and waste trucked out. And as droughts intensify, concerns rise over the massive quantities of water required to extract for hydraulic fracturing.

In February 2013, the EPA reported that petroleum and natural gas systems, including fracking, constituted the second largest sector in terms of greenhouse gas emissions. (See EPA's interactive map to locate these facilities.)

Journalists and researchers have dug deep into the issue. To name just a few: Andrew Revkin, author of the New York Times' "Dot Earth" blog, has had much to say about the potential health impacts of shale gas; Tom Wilber, author of Under the Surface, has been tracking the issue; at ProPublica, Abrahm Lustgarten and others have published many investigative pieces on fracking and curated a collection of other journalistic work; Bryan Walsh of Time has covered the issue closely.

Nature magazine has also produced a helpful point-counterpoint to illustrate the legitimate concerns of those on both sides of the issue. Meanwhile, the EPA continues to study the impacts on drinking water resources.