Tracking mercury emission flows in the global supply chains: A multi-regional input-output analysis

Abstract

Mercury emissions from nonferrous metal production have overtaken that from energy consumption as the leading contributor of global anthropogenic mercury emissions. Though Minamata Convention has put restrictions on import or export of mercury-added products, the inter-connected global economy that features an intensive correlated supply chain still has large impacts on mercury emissions. Therefore, this study aims to track global nonferrous metal related mercury emission flows among 186 individual economies for the year of 2010, by applying an empirically validated multi-regional input-output (MRIO) model. The total amount of direct mercury emissions is 974 tonnes, to which gold production contributed a dominant proportion. However, a spectacular 2/3 of mercury emissions from nonferrous metal production were traded internationally, primarily as exports from emerging economies such as mainland China and Colombia to wealthy economies including the USA and Germany through global supply chains. Understanding the redistribution of mercury emissions along the global supply chains can facilitate international efforts to reduce mercury emissions from nonferrous metal production.