Coal mining

Coal has been mined since ancient times, with evidence of use in Roman Britain and medieval China. The Industrial Revolution in the 18th and 19th centuries transformed coal mining from a small-scale operation into a massive industry, driven by the demand for steam engines and iron production.¹ Early mines were shallow and often used manual labor, but technological advances such as the steam-powered pump and the safety lamp enabled deeper and safer extraction. By the late 19th century, coal was the world's primary energy source, powering factories, railways, and ships.

Surface mining, including open-pit and strip mining, is used when coal seams are close to the surface. It involves removing overburden to expose the coal, and it accounts for about 60% of global production. Underground mining, used for deeper seams, employs techniques such as longwall and room-and-pillar mining. Longwall mining uses a mechanical shearer to extract coal along a long face, while room-and-pillar leaves pillars of coal to support the roof. Each method has distinct environmental impacts: surface mining disturbs large areas of land, while underground mining can cause subsidence and methane emissions.

Coal mining has severe environmental consequences, including habitat destruction, water pollution from acid mine drainage, and air pollution from dust and methane. Burning coal is the largest single source of global CO2 emissions, contributing to climate change.² Health impacts on miners include black lung disease (coal workers' pneumoconiosis), which has caused thousands of deaths worldwide. In the United States, federal regulations have reduced dust exposure, but the disease persists among older miners.³ Coal mining also affects local communities through displacement and economic dependence, often leading to boom-and-bust cycles.

Coal remains a major economic driver in countries like China, India, and Australia, providing jobs and export revenue. In 2023, China produced over half of the world's coal, and India is the second-largest producer.⁴ Coal trade is a significant geopolitical factor, with major exporters including Australia, Indonesia, and Russia. However, the industry faces decline in many regions due to competition from natural gas and renewables, as well as climate policies. The transition away from coal is a contentious issue, as it affects energy security and livelihoods.

Beyond the well-known impacts, coal mining has niche and surprising dimensions. For example, coal mine methane is sometimes captured and used as a fuel, reducing greenhouse gas emissions. In some regions, abandoned mines are repurposed for pumped-storage hydroelectricity or as sites for carbon capture and storage. Historically, coal mines were also sources of rare minerals, such as germanium, which is extracted from coal ash. Additionally, the concept of 'mountaintop removal' mining, prevalent in Appalachia, has led to unique ecological and social studies. Another obscure fact: the world's deepest coal mine, in the UK, reached depths of over 1,200 meters, and some mines have been used for scientific research, such as neutrino detection.

Longwall mining

An underground mining method that extracts coal along a long face using a mechanical shearer, allowing for high productivity and roof collapse behind the face.

Acid mine drainage

The outflow of acidic water from mines, often containing heavy metals, caused by the oxidation of sulfide minerals.

Black lung disease

Coal workers' pneumoconiosis, a respiratory disease caused by long-term inhalation of coal dust.

Mountaintop removal

A form of surface mining that removes the summit of a mountain to expose coal seams, often resulting in valley fills and environmental damage.