Shale gas vs. coal: Policy implications from environmental impact comparisons of shale gas, conventional gas, and coal on air, water, and land in the United States

► We examine the impacts of (un)conventional gas and coal on air, water, and land. ► A shift from coal to shale gas would benefit public health. ► Shale gas extraction can affect water safety. ► We discuss technical solutions to fix the most crucial problems of shale gas extraction. ► We recommend hybrid regulations.