Currently unaccounted for, unremediated discharge from old mines can transport CO2 from bedrock to the atmosphere.
Currently unaccounted for, unremediated discharge from old mines can transport CO2 from bedrock to the atmosphere.
For the past 250 years, people have mined coal industrially in Pennsylvania, USA. By 1830, the city of Pittsburgh was using more than 400 tons of the fossil fuel every day. Burning all that coal has contributed to climate change. Additionally, unremediated mines—especially those that operated before Congress passed regulations in 1977—have leaked environmentally harmful mine drainage. But that might not be the end of their legacy.
In research presented last week at GSA Connects 2025 in San Antonio, Texas, USA, Dr. Dorothy Vesper, a geochemist at West Virginia University, found that those abandoned mines pose another risk: continuous CO2 emissions from water that leaks out even decades or centuries after mining stops.
In a 2016 study, Vesper and her collaborators found that the water draining from just 140 of these mines in Pennsylvania add as much CO2to the atmosphere each year as a small coal-fired power plant. Considering officials and scientists don’t know the number of abandoned mines in Pennsylvania, let alone elsewhere, the impact of these mines is an unresolved and important part of understanding the sources of human-caused climate change.
Read More: Geological Society of America
