Provincial emission accounting for CO2 mitigation in China: Insights from production, consumption and income perspectives

Emission accounting can help to identify main CO2 emitters and inform emission mitigation policymaking. Previous studies have proved that the application of different accounting principles results in different emission levels, thus bring different policy implications, while the emissions enabled by primary inputs (or income-based emission) have been overlooked in studies for carbon mitigation in China. Understanding the role of primary inputs in CO2 emissions is a prerequisite to create efficient supply-side mitigation policies. Here, we conduct a quantitative study of China's provincial production-, consumption-, and income-based CO2 emissions in a unified multi-regional input-output analysis framework. The results are compared from the three perspectives for 30 provinces in China to help the government identify the main policy targets from production, demand, and supply sides. We found that 64% and 35% of China's emissions are transferred among provinces driven by final demands and primary inputs, respectively. Mitigation policies in heavily industrialized provinces, such as Hebei, Liaoning, and Henan, where the production-based emissions are higher than the consumption- and income-based emissions, should be focused on production side. Similarly, policies in eastern coastal developed provinces and resource-abundant provinces should be focused on demand- and supply-side, respectively. Moreover, we found that tertiary industries, which previous studies generally regard as low-carbon industries, are the major contributors to China's income-based CO2 emissions with a total of 2026 Mt or 31% of China's total income-based CO2 emissions. Thus, expanding tertiary industries without reducing their industrial linkages to carbon-intensive industries is not conducive to China's emission reduction.