A smoking gun in the form of methane isotopes links the two.

Shale Gas: Game Changer or Potential Problem?

The abundant, cleaner-burning fossil fuel known as shale gas has been hailed as a bridge fuel that’ll allow the transition from coal to a renewable-fueled future. Not only that, drilling for shale gas has propped up economies in some of the country’s down-and-out regions.

But its pursuit has led some to cry foul, thanks to the process by which the stuff is extracted — horizontal drilling and hydraulic fracturing (which cracks the rock through high-pressure injections of a mix of water, sand, and chemicals). Homeowners living near hydrofracturing sites have complained of contaminated drinking-water wells. The plight of these folks was