The phrase "coal mine" refers to an underground place where coal, a type of black mineral, is extracted or dug out from the ground to be used as fuel for things like electricity or heating. Full definition
However, the decrease in CO2 emissions will be greatly offset by the increasing need to import electricity from coal plants in other countries. (ddears.com)
Not only does it result in double the global warming emissions as oil, it would lead to an increase in coal mining which destroys rivers and threatens community health. (coal-is-dirty.com)
Moving away from coal for power generation would help tremendously, and the mining industry needs to clean up its act. (treehugger.com)