Global methane emissions from coal mining to continue growing even with declining coal production

Area of Science:

• Environmental Science
• Climate Change Research
• Geological Engineering

Background:

• Methane is a potent greenhouse gas, and coal mining is a significant source of its atmospheric emissions.
• Previous estimates of coal mining methane emissions may have underestimated the total contribution.
• The increasing depth and scale of coal extraction, alongside a growing number of abandoned mines, necessitate updated emission calculations.

Purpose of the Study:

• To project global methane emissions from coal mining activities through 2100.
• To develop and apply an updated methodology for calculating fugitive methane emissions from both active and abandoned coal mines.
• To provide a more accurate assessment of current and future methane emissions from the coal mining sector.

Main Methods:

• Developed an updated methodology for calculating fugitive emissions from coal mining, incorporating coal extraction method, coal rank, and mining depth.
• Utilized evidence-based emissions factors for improved accuracy.
• Applied a novel methodology for estimating methane emissions from abandoned coal mines.
• Incorporated coal production data from six integrated assessment models for future projections.

Main Results:

• Coal mining-related methane emissions in 2010 were found to be higher than previously reported.
• Emissions from abandoned coal mines are projected to increase at a faster rate than those from active mines.
• By 2100, methane emissions from active underground mines are projected to increase fourfold, while emissions from abandoned mines are projected to increase eightfold.
• Methane emissions from abandoned mines are expected to persist throughout the century, irrespective of mitigation strategies.

Conclusions:

• The study highlights the critical need for accurate methane emission accounting from all coal mining activities, including abandoned sites.
• Future methane emissions from coal mining, particularly from abandoned mines, pose a substantial challenge to climate change mitigation efforts.
• Policy and technological interventions must consider the long-term and escalating impact of abandoned mine methane emissions.