Can Switching from Coal to Shale Gas Bring Net Carbon Reductions to China?

To increase energy security and reduce emissions of air pollutants and CO₂ from coal use, China is attempting to duplicate the rapid development of shale gas that has taken place in the United States. This work builds a framework to estimate the lifecycle greenhouse gas (GHG) emissions from China's shale gas system and compares them with GHG emissions from coal used in the power, residential, and industrial sectors. We find the mean lifecycle carbon footprint of shale gas is about 30-50% lower than that of coal in all sectors under both 20 year and 100 year global warming potentials (GWP₂₀ and GWP₁₀₀). However, primarily due to large uncertainties in methane leakage, the upper bound estimate of the lifecycle carbon footprint of shale gas in China could be approximately 15-60% higher than that of coal across sectors under GWP₂₀. To ensure net GHG emission reductions when switching from coal to shale gas, we estimate the breakeven methane leakage rates to be approximately 6.0%, 7.7%, and 4.2% in the power, residential, and industrial sectors, respectively, under GWP₂₀. We find shale gas in China has a good chance of delivering air quality and climate cobenefits, particularly when used in the residential sector, with proper methane leakage control.