An Improved Approach to Estimate Methane Emissions from Coal Mining in China

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Climate Change Research

Background:

• China leads global coal production, contributing over 50% of worldwide methane (CH4) emissions from coal mining.
• Existing CH4 emission inventories for Chinese coal mining suffer from significant uncertainties due to a lack of localized emission factors (EFs).

Purpose of the Study:

• To develop localized, province-level CH4 emission factors (EFs) for coal mining in China.
• To establish a more accurate CH4 emission inventory for China from 2005-2010.
• To forecast future CH4 emissions from Chinese coal mining through 2020.

Main Methods:

• Analyzed coal production and CH4 discharge data from 787 mines across 25 Chinese provinces.
• Developed province-specific CH4 EFs, revealing significant spatial variability (0.74–36 m3/t).
• Constructed gray forecasting and regression models to estimate CH4 EFs and activity data for future emissions projections.

Main Results:

• China's total CH4 emissions from coal mining rose from 11.5 Tg in 2005 to 16.0 Tg in 2010.
• Newly developed EFs and inventory estimates show reasonable agreement with EPA data, but are 1-2 times lower than IPCC default EFs.
• Forecasts predict CH4 emissions from Chinese coal mining for 2011-2020.

Conclusions:

• This study provides crucial, localized CH4 emission factors for China's coal mining sector.
• The findings offer a more accurate baseline for CH4 emissions and future projections.
• Results can inform targeted CH4 mitigation strategies and policies in China's coal industry.