Volume 4, Issue 4 (2025) – 15 articles
Cover Picture: Methane is a potent greenhouse gas with a 100-year global warming potential of 27.9 and has become a major focus in global climate governance. As a major emitter, China faces substantial challenges in managing methane emissions from its waste sector. This study examines the patterns of methane generation and the potential for mitigation across different waste disposal systems in China. We established a comprehensive methane accounting model and quantified emissions from four waste sectors: municipal solid waste, urban sewage, agricultural cropping, and livestock and poultry farming. Using data from 2018 to 2022, we found that total methane emissions from waste in China were 10.2 million tons in 2022, representing a 27.8% decline, mainly due to substantial reductions in municipal solid waste emissions. In contrast, emissions from agricultural sources, particularly livestock and poultry farming, have increased, underscoring the need for targeted mitigation strategies. To assess future pathways, three policy scenarios were designed: Business as Usual (BAU), Urban Waste Recycling (UWR), and Agricultural Carbon Reduction and Sequestration (ACRS). The projections for 2025-2030 indicate that the ACRS scenario yields the greatest reduction in methane emissions, driven primarily by straw-to-fuel utilization and improved livestock manure management. This study provides valuable insights into the sources, drivers, and future trajectories of methane emissions from waste in China, and offers policy recommendations to maximize methane mitigation benefits while minimizing greenhouse gas abatement costs.
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Back Cover Picture: Previous studies indicate that rapid electric vehicle (EV) adoption, together with synchronized expansion of renewable electricity (RE) in all power grid regions, could significantly reduce life cycle carbon emissions from China’s road transport sector. However, the varying pace of EV and RE development in different regions complicates this goal. There is a lack of research analyzing the impact of prioritizing vehicle electrification and RE expansion within specific power grid regions on national life cycle carbon emission reductions. This study employed a highly disaggregated engineering-based model to estimate the life cycle carbon emissions from China’s road transport from the base year 2020 up to 2050 under various EV and RE development scenarios with different regional priorities. The underlying reasons and key processes driving variations in carbon emission reductions at the power grid region level were also analyzed. Our results indicate that the Central and Northwest power grid regions contributed the most and least to life cycle carbon emissions in 2020, respectively. Implementing fast RE and EV development pathways in the North, Northeast, and Northwest power grid regions (where emissions are mainly from vehicle use and the energy supply chains) while maintaining baseline pathways in Central, East, and South could reduce national life cycle carbon dioxide (CO2) emissions from 2,186 Mt in 2020 to 1,486 Mt in 2050. Conversely, focusing on fast RE and EV development in the Central, East, and South regions, where vehicle and battery production is mainly located, would only reduce emissions to 1,901 Mt by 2050. Our findings suggest that prioritizing synchronized fast RE and EV development at a power grid region level would be more effective than doing so at a national level in reducing the overall life cycle CO2 emissions from China’s road transport by 2050. Light-duty passenger vehicles, heavy-duty trucks, and light-duty trucks are the main vehicle types contributing to CO2 emissions in various regional prioritization in vehicle electrification and RE expansion.
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