Coal Mining Emits More
Super-Polluting Methane Than Venting and Flaring
From Gas and Oil Wells, a New Study Finds
So much
methane is released from coal mining, the Global Energy Monitor says,
that it exceeds the carbon dioxide emissions from burning coal at over
1,100 coal-fired power plants in China.
An aerial view of a coal mine in
Merthyr Tydfil, Wales on November 1, 2021. Credit: Matthew Horwood/Getty
Images
Methane emissions from coal mines
worldwide exceed those from the global oil or gas sectors and are
significantly higher than prior estimates by the Environmental
Protection Agency and the International Energy Agency, a new
Global Energy Monitor report concludes.
“The numbers just aren’t adding up,” Ryan
Driskell Tate, the report’s author, said of coal mine methane emission
estimates when compared to those in prior reports. “It’s an area that
has dodged a lot of scrutiny.”
Coal mining emits 52 million metric tons
of methane per year, more than is emitted from either the oil sector,
which emits 39 million tons, or the gas industry, which emits 45
million tons, according to
the report, published Tuesday.
Methane, the primary component of natural
gas, is a potent greenhouse gas and the second leading driver of
climate change after carbon dioxide. On a unit-per-unit basis, methane
is more than 80 times as powerful at warming the planet as carbon
dioxide over its first 20 years in the atmosphere. The gas slowly
accumulates in coal seams as organic matter is converted to coal, a
process that can take millions of years.
Methane emissions from coal mining
worldwide are comparable to the vast carbon dioxide emissions from
burning coal at
over 1,100 coal-fired power plants in China over the near term,
the report concludes. China, the world’s largest greenhouse gas
emitter, derived
more than 60 percent percent of its power in 2020 from burning
coal, compared to about 19 percent in the United States.
“We all know that the oil and gas
industry emits a lot of methane and that coal plants in China are a
major source of CO2 emissions,” said Driskell Tate, the energy
monitor’s project manager for its Global Coal Mine Tracker. “The most
surprising thing about this report is just realizing that coal mining
has a comparable climate impact.”
Measurements From
Thousands of Coal Mines
Measuring emissions from approximately
2,300 coal mines in operation worldwide, the Global Energy Monitor
report found emissions were 50 percent higher than a 2019 estimate by
the EPA and 20 percent higher than an estimate earlier this year by
the International Energy Agency. Both the EPA and IEA estimates relied
on national averages rather than more specific figures from individual
mines.
Other prior estimates for global coal
mine methane emissions were even higher than those in the current
report. However, the Global Energy Monitoring report is the first to
take a detailed look at emissions from individual mines.
The current analysis drew data from the
organization’s Coal Mine Tracker, a database that includes detailed
information on nearly all coal mines worldwide, including the type and
volume of coal extracted from each. The database also includes the
depth of each mine, which can play a key role in how much methane a
mine releases.
“One of the biggest contributions of this
report is the level of detail and information that they provide about
individual coal mines across the globe,” said Scot Miller, an
environmental health and engineering professor at Johns Hopkins
University. “If we want to mitigate these emissions, we need to know
more than country level emissions. We need to know where these mines
are, and how much methane is coming out of each mine so that we can
develop effective mitigation strategies.”
The information on individual mines was
combined with the Model for Calculating Coal Mine Methane, a method of
calculating emissions developed by researchers at the Pacific
Northwest National Laboratory, the EPA and other industry experts. The
report found that some high-emitting mines can emit 67 times more
methane than similarly sized mines.
China’s Vast Emissions
From Coal
China is far and away the leading source
of coal mine methane emissions, the report said, warning that
additional mines currently under development in China and other Asian
countries will fuel additional warming.
Miller said the report’s information on
the projected emissions of proposed mines or mine projects currently
under development could help guide climate policy in China and other
countries. Countries could, for example, pursue mines with lower
projected emissions or focus on capturing methane emissions for
electricity generation or heating projects from mines with higher
projected emissions.
Capturing methane emissions from coal
mines for use in energy production or heating has proven more
difficult than similar emissions from the oil and gas industry because
the majority of emissions are more diffuse. China set ambitious
targets to capture and use methane from coal mining by 2015. However,
a study published by Miller in 2019 found
China was not meeting its targets.
That study only looked at emissions
through 2015. Miller said that “the jury is out” on whether policies
in China have been more effective at reducing coal mine methane
emissions in more recent years.
Stefan Schwietzke, a senior scientist
with the Environmental Defense Fund and a science advisor for the
United Nations Environment Program’s recently launched International
Methane Emissions Observatory, praised the study’s look at individual
mines. He said actual emissions data from individual mines would
provide an even clearer picture of coal mine methane emissions and is
working on a study for UNEP that would do just that.
The current report notes that the best
way to reduce methane emissions may be to simply stop opening new
mines and shut down existing mining operations. However, the report
also notes that even closed mines can continue to be a significant
source of methane emissions.
While the U.S. and other developing
countries are rapidly phasing down coal use, developing countries
continue to rely heavily on it, the dirtiest fossil fuel, which has
contributed more to global warming than either oil or gas.
“What we often forget about, in many
other countries outside of the United States coal is still the primary
source of electricity, especially in countries like China and India,”
Miller said. “Beyond what we do in the United States or Europe to
mitigate greenhouse gas emissions, we really can’t forget about
emissions problems like tackling methane from coal mining in other
countries.”
Phil McKenna is a Boston-based
reporter for Inside Climate News. Before joining ICN in 2016, he was a
freelance writer covering energy and the environment for publications
including The New York Times, Smithsonian, Audubon and WIRED.
Uprising, a story he wrote about gas leaks under U.S. cities, won the
AAAS Kavli Science Journalism Award and the 2014 NASW Science in
Society Award. Phil has a master’s degree in science writing from the
Massachusetts Institute of Technology and was an Environmental
Journalism Fellow at Middlebury College.
