One university scientist even wrote a paper alleging that greenhouse emissions from shale gas production are worse than the burning of coal.

FORBES: Why Anti-Fracking Groups Are Shifting Their Story From Water To Air Quality

Earlier this month, scientists at Duke University published a paper in the Proceedings of the National Academies that provided evidence of a link between shale-gas wells and methane contamination in nearby drinking water supplied.

FORBES: Pennsylvania Pins Record Fine on Shale-Gas Producer