A Comprehensive\nAccounting of Construction Materials\nin Belt and Road Initiative Projects

The Belt and Road Initiative (BRI) stands as the most\nambitious\ninfrastructure project in history, marked by its scale of investment,\nextensive geographical reach across continents and countries, and\na diverse array of projects from roads to digital networks. While\nthe BRI’s environmental sustainability has raised concerns,\nthe impacts of construction materials used in these projects have\nbeen overlooked, especially in developing countries. Here, we map\nand account for the materials embodied in the BRI by integrating,\nfor the first time, official governmental project reports, geographical\ninformation, and material flow analysis. We pinpoint and analyze the\nBRI material stocks in each individual project by material types,\ncountries, regions, and sectors. Between 2008 and 2023, 328 million\ntons of construction materials have accumulated in 540 BRI projects\naround the world, mostly in Asia and Africa. Aggregates (sand and\ngravel) constitute the largest share (82%), followed by cement, steel,\nand other materials. Most of the materials are used in transportation\ninfrastructure. Our work further highlights some limitations in terms\nof data quality for such sustainability assessments. By shedding light\non the significant impact of BRI projects on raw material usage across\nthe globe, this study sets the stage for further investigations into\nenvironmental impacts of BRI and material stock-flow-nexus from perspective\nof an initiative.