Environmental and social governance (ESG) has long been a key issue along global metals and mining supply chains. From carbon emissions and water use in metal processing to conflict minerals, human rights abuses and child labour in mining areas, the extractive industries and their end consumers – as well as the financiers who support the underlying trade – need to track myriad threats in order to remain compliant with increasingly stringent regulations. New blockchain-based initiatives look set to facilitate this, but does the technology have all the answers? Eleanor Wragg reports.