By Tim Sandle

February 4, 2021 - A new risk factor has been identified in relation to methane levels in the atmosphere – abandoned coal mines. New research identifies form mines as concentrated sources of methane gas release.

Although coal production and associated mining are at their lowest level in 30 years, abandoned mines around the world are causing major environmental problems. As Laboratory Roots finds, mines can catch fire, and debris from them can contaminate the water supply, and they are also the source of major atmospheric pollutants. Yet mine clean-up is a major effort. It is also one, in the U.S. context, that appears to be difficult to fund, since many of the coal companies responsible for them are claiming bankruptcy. 

This needs to be considered in the context of new research that finds methane continues to be emitted from thousands of abandoned mines at a rate greater than previously realized. In addition, there is an even higher methane content in coal seams in terms of the deepest reaches of a mine. With this point, coal from mines that reach over 400 meters deep contains double the amount of methane compared to coal from mines that only penetrate down to 200 meters deep (what are classed as shallower mines).

Methane comes from natural sources, such as wetlands and animal digestion, along with thermogenic sources, including coal, oil and gas production. Methane levels are of a concern since it is one of the gases that trap heat in the atmosphere. These gases are called greenhouse gases.

The following video expands upon the research findings:

The new research was presented by a team of collaborators from the U.S. Department of Energy's Pacific Northwest National Laboratory and the U.S. Environmental Protection Agency.

The inference from the findings are that the closure of mines is something that needs to be undertaken in a more careful and controlled way, in terms of the way that mines are closed down and monitored for safety and pollutants. The scientists warn that unless coordinated action is taken, then methane emissions as a result of coal mining will increase almost eightfold by the end of the century.