Yale Environment 360: Thousands of abandoned coal mines dot the U.S. landscape, vestiges of old fossil fuel boomtowns and industrial hubs. But despite no longer producing coal, these sites are still contributing to climate change by leaking carbon dioxide into the atmosphere, according to a recent study by scientists at West Virginia University. The total amount of CO2 released annually by 140 abandoned sites in Pennsylvania is equal to that of a small coal-fired power plant, says the study, published in Environmental...