Pair of studies released this week offer different takes on methane leaks from oil and gas wells

Researchers at Princeton University say that 19 abandoned wells in Pennsylvania are emitting high levels of methane, Richard Valdmanis reports for Reuters. The study, which was conducted in 2013-14 and published this week in the Proceedings of the National Academy of Sciences, says that wells were emitting an average of 0.27 kg (0.6 lbs) of methane per day.

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

Researchers "estimate that abandoned wells in Pennsylvania could account for 4-7 percent of all human-sourced methane emissions in the state," Doyle Rice reports for USA Today. "The researchers say the wells in Pennsylvania could be representative of all the wells across the country."

A University of Texas study published this week in the journal Environmental Science & Technology—and supported by several natural gas companies and the Environmental Defense Fund—"found that leaks at a small group of wells—about 20 percent—cause most of the known methane emissions," Rice writes.

The wells extract natural gas through hydraulic fracturing, known as fracking, Rice writes. David Allen, a chemical engineering professor at the University of Texas and the study's lead author, told Rice, "To put this in perspective, over the past several decades, 10 percent of the cars on the road have been responsible for the majority of automotive exhaust pollution." (Read more)