Inter-regional spillover of China's sulfur dioxide (SO₂) pollution across the supply chains

Inter-regional spillover of air pollution can be regarded as a mixture of economic externalities and long-distance transport. To comprehensively reveal this problem, a new consumption-based sulfur dioxide (SO ₂) emission inventory in 2010 for 30 provincial regions of China was compiled by introducing source-receptor relationship (SRR) model to integrate the spillover impacts of physical transport from the emitter (producer) region to the receptor region and virtual transfer from the driver (consumer) region to the emitter region. Compared the emissions induced by final regional demand with the emissions received in seven regions of China, Southern (0.59 Mt), Northern (0.25 Mt), Northwestern (0.18 Mt), and Eastern (0.14 Mt) areas outsourced SO ₂ pollution in the mass, whereas Central (−0.66 Mt), Northeastern (−0.42 Mt), and Southwestern (−0.08 Mt) areas took excessive environmental burdens in 2010. The four municipalities, Chongqing, Shanghai, Beijing, and Tianjin as well as the most affluent province Guangdong showed significant pollution transfer after an overall assessment of their roles in drivers, emitters and receptors. Shanxi, Inner Mongolia, Guizhou, Henan, and Shandong showed the largest co-benefits of SO ₂ emissions control for climate change mitigation. Japan was found to receive more portions of transboundary SO ₂ deposition than its market shares in China's export instead of other major trade partners of China. As a mega-city, Beijing induced significant SO ₂ emissions for power requirement, food consumption, miscellaneous services, and her vibrant research activities through the sectors of the power industry, coal mining, chemical manufacturing, food-related industries, petroleum processing and coking, but 86% of those emissions were outsourced by Beijing. In total, the spillover of SO ₂ emissions induced by Beijing was estimated at 0.20 Mt, 76 times more than its own share as a receptor across the supply chains. This study is competent for an analytic framework of strategic planning for joint prevention and control of air pollution in China and other countries. The results can help reduce pollution transfer, properly tax on drivers, effectively control the emitters, and reasonably compensate the receptors.