The impact of domestic and foreign trade on energy-related PM emissions in Beijing

Particulate matter (PM) adversely affects air quality, human health and the climate, and it is more prevalent in urban areas. Few efforts have been made to quantify the impact of trade on PM concentrations in an urban economy. This paper presents an analysis of the impacts of domestic and international trade on PM emissions in Beijing using a three-scale input–output model, supported by the national and global embodied energy-related PM_2.5, PM₁₀ and TSP (total suspended particulate) emission intensities. The results found that the total energy-related PM_2.5, PM₁₀ and TSP emissions (production-based) in Beijing were 106 Gg, 163 Gg and 347 Gg, respectively, in 2010. Of these amounts, 48% (51 Gg, 74 Gg and 146 Gg, respectively) was associated with local demand, 42% (44 Gg, 73 Gg and 168 Gg, respectively) was associated with domestic exports, and 10% (11 Gg, 16 Gg and 33 Gg, respectively) was associated with international exports. From a consumption perspective, Beijing's PM_2.5, PM₁₀ and TSP emissions were more than double the production-based PM emissions. Approximately 75% (172 Gg, 311 Gg and 786 Gg, respectively) of the consumption-based PM emissions were domestically outsourced to other provinces, primarily via the import of metal (32 Gg, 58 Gg and 151 Gg), construction (26 Gg, 36 Gg and 91 Gg) and chemical products (16 Gg, 30 Gg and 75 Gg), and 3% (8 Gg, 10 Gg and 24 Gg, respectively) of consumption-based PM emissions were outsourced abroad. Our results indicate that domestic trade plays a dominant role in Beijing's PM_2.5 emissions. These findings suggest that more national and sub-national government should co-ordinate design and implement effective mechanisms to alleviate urban air pollution because of the significant effects of interprovincial and international trade on local emissions.