From Princeton University: Wells that extract natural gas from underground often leak large amounts of methane, a powerful greenhouse gas, into the air. A team of Princeton University researchers has found that, in one of the biggest gas-producing regions, most of these emissions come from a tiny subset of the wells, a finding with major implications for how to control the problem. Researchers led by Mark Zondlo , an associate professor of civil and environmental engineering , spent two years sampling emissions from the Marcellus Shale, a basin that stretches from West Virginia into New York State. In research published in the journal Environmental Science and Technology, the authors reported that 10% of wells account for more than three quarters of gas leaked into the atmosphere as a byproduct of extraction. That has the equivalent greenhouse gas effect of adding 500,000 cars, or about 2% of the U.S. auto market, to the road. This finding, however, may have a silver lining ...