China's energy-related mercury emissions: Characteristics, impact of trade and mitigation policies

Abstract

As the world's largest energy consumer, China contributes significantly to the global atmospheric mercury emissions, a toxic air pollutant with global importance. This study aims to systematically analyze China's energy-related mercury emissions in light of environmentally extended input-output analysis (EEIOA), considering the impact of China's inter-sector connection and external trade. The results reveal that embodied emission intensities of some manufacturing sectors are magnified about 100 times compared with their corresponding direct mercury emission intensities. Generally, the magnified effect of upstream sectors (e.g., Sector Coal Mining) is less remarkable than downstream sectors (e.g., Sector Electric Equipment and Machinery Manufacturing), underlying the effect of inter-sector connection. As for external trade, over a quarter of China's direct mercury emissions from fuel combustion (359.7 tonnes) are attributed to foreign consumption of commodities produced in China, manifesting China's role as world factory. Due to the prominent role of China's processing trade, mercury emissions embodied in re-exports takes a considerable amount of total emissions embodied in China's exports. These findings have implications for China's mercury pollution mitigation policies focusing on different stages in domestic supply chains and responsibilities redistribution of international collaborative mitigation.