Comparative analysis of certified emission reduction methodologies for methane emission reduction in China

As one of the top emitters of methane (CH₄), China must take action to achieve its carbon neutrality goal. Programs to reduce CH₄ emissions would benefit from the establishment of the China Certified Emission Reduction (CCER) trading market. However, studies investigating the impact of the CCER trading market on CH₄ reduction remain limited. This study therefore analyzes the emission reduction performance of CH₄-related CCER projects and investigates their accounting methodologies. The results show that 182 CH₄ emissions reduction projects were registered between 2012 and 2017, covering coal mining, energy, waste treatment and disposal, and agriculture, with an annual emissions reduction of 19.8 MtCO₂e. It was observed that, while the pre-restart methodology system covered a wide range of emission reduction areas, its application frequency was unevenly distributed. Most projects were registered in only a few emission reduction domains, with the majority of methodologies remaining unused since their publication. Moreover, the IPCC default values were frequently used in China-specific emission accounting, leading to significant uncertainties. Recommendations are made on how to improve the effectiveness of CH₄ emissions reduction measures based on this analysis.