中美贸易模式变化对中国大气汞排放的影响

Impacts of the Changing Sino-US Trade on China’s Atmospheric Mercury Emissions

在全球贸易体系中,美国是中国大气汞排放的主要外部消费驱动力之一。现有研究多核算国际贸易驱动的大气汞排放,识别主要的贸易驱动关系,缺乏中美贸易模式变化对中国大气汞排放的影响分析。本文基于环境扩展型投入产出模型和结构分解分析方法,计算了1997—2017年中美贸易驱动的中国大气汞排放量,并深入分析了贸易相关的社会经济因素对中国大气汞排放变化的相对贡献。研究结果表明:1997—2007年,中美贸易驱动的中国大气汞排放从13.5 t增至32.8 t,2007年后开始回落,2017年回落至13.6 t。贸易规模扩大是推动大气汞排放增加的最主要因素(62.6 t),排放强度降低是大气汞排放减少的最大驱动因素(-67.0 t)。生产技术水平变化和贸易结构变化的贡献相对较小,近年来逐渐起到促进大气汞排放减少的作用,但其贡献不稳定。根据研究结果,提出了加快产业创新升级,优化、稳定贸易结构,提升产品竞争力等建议。

The United States(US) is one of the major foreign consumers driving atmospheric mercury(Hg) emissions in China. Existing studies mostly focus on the quantification of China’s atmospheric Hg emissions driven by international trade. However, the impacts of the changing Sino-US trade on the changes of atmospheric Hg emissions in China remain unknown. Based on the environmentally extended input-output model, this study calculated the atmospheric Hg emissions in China driven by the Sino-US trade from 1997 to 2017. Combined with structural decomposition analysis, we further investigated the relative contributions of trade-related socioeconomic factors to the changes of China’s atmospheric Hg emissions. Results showed that: from 1997 to 2007, atmospheric Hg emissions in China driven by the Sino-US trade increased from 13.5 t to 32.8 t, then dropped to 13.6 t in 2017. The expansion in trade scale was the major driver driving the increase of atmospheric Hg emissions(62.61 t), while the reduction of atmospheric Hg emission intensity was the biggest driving factor for the reduction of induced atmospheric Hg emissions(-66.97 t). The relative contributions of changes in production technology levels and trade structure were relatively small. In recent years, changes in these two factors had generally played a role in reducing the induced atmospheric Hg emissions, but its contributions were unstable. Based on the results, we proposed policy suggestions such as accelerating industrial innovation and upgrading, optimizing and stabilizing the trade structure,and enhancing product competitiveness.