Unveiling the changes of carbon emissions along supply chains: Drivers and sustainable mitigation strategies

China's annual carbon emissions decreased year by year during 2013–2016 and increased after 2016. Such fluctuation prompts important questions about the factors that drove the decrease and increase, and the desired pathway(s) to sustain a continuous reduction. With the consideration of supply-demand relationships, we quantitatively evaluate the socioeconomic drivers of carbon emission changes along supply chains. Here we find that from a supply perspective, industrial adjustment has negative impacts on the emission reduction of service-driven paths. For paths involving the electricity-generation sector, the adjustment of primary input structure has positive effects on path-level emission reduction (since 2007). The construction sector can adjust its consumption structure to help accelerate the system's low-carbon transition. For the supply- and demand-oriented paths, the mitigation effects of emission intensity will weaken if more sectors are involved in production activities. Further emission reductions may rely on both reducing emission intensity and minimizing the utilization of deep-processed products.