Gauging the impact of global trade on China's local environmental burden

摘要

The explosive expansion in China's exports has brought about many local (domestic) environmental problems. Understanding the magnitude and structure of the pollution emissions embodied in these exports is crucial for developing policies not only for local environmental stewardship and cleaner production, but also for international trade. We introduce a stochastic modification of the customary (economic) input-output model in order to reconstruct information typically absent from a traditional national input-output table but vital for understanding where export-embodied pollution emissions are generated in an open economy. Specifically, our modification enables a better means of "subtracting out" the pollutant emissions that might have been associated with imported intermediate inputs (before their arrival in China). We find, nevertheless, that large proportions of emissions of heavy metals (Cr~(6+) and Pb) contained in wastewater can be attributed to exports. In 2007, these figures reached more than 40% of their respective total emissions. Total quantities of export-embodied wastewater, sulfur dioxide (SO_2) and solid waste have increased dramatically from 1997 to 2007. The relative rates of growth in the percentages of export-embodied pollutants in total industrial emissions, however, were lower than the relative rate of growth in the percentage of exports in China's total GDP over this same decade. Three clusters of sectors play dominant roles in driving China's export embodied emissions: textiles, leather and clothing apparel; electrical and electronic equipment; and the chemical industry. We suggest that promoting the transition in the distribution of export products toward high value-added and low embodied-emission products and services (themselves enhanced by cleaner production methods) should be regarded as a long-term goal of China's trade policy.