Date Time Methane Emissions from Coal Mines Are Higher Than Previously Thought COLLEGE PARK, Md.-The amount of methane released into the atmosphere as a result of coal mining is likely much higher than previously calculated, according to research presented at the annual meeting of the American Geophysical Union recently. The study estimates that methane emissions from coal mines are approximately 50 percent higher than previously estimated. The research was done by a team at the U.S. Department of Energy’s Pacific Northwest National Laboratory, the U.S. Environmental Protection Agency and others. The higher estimate is due mainly to two factors: methane that continues to be emitted from thousands of abandoned mines and the higher methane content in coal seams that are ever deeper, according to chief author Nazar Kholod of PNNL.