"BOSTON -- Some of the millions of abandoned oil and natural gas wells in the United States are still spewing methane, marking a potentially large source of unrecorded greenhouse gas emissions, according to a study released on Monday.

Researchers at Princeton University measured emissions from dozens of abandoned wells in Pennsylvania in 2013 and 2014 and found they were emitting an average of 0.27 kg (0.6 lbs) of methane per day, according to the study published in the Proceedings of the National Academy of Sciences.

'These measurements show that methane emissions from abandoned oil and gas wells can be significant,' according to the study. 'The research required to quantify these emissions nationally should be undertaken so they can be accurately described and included in greenhouse gas emissions inventories.'"

Richard Valdmanis reports for Reuters December 8, 2014. [2]