Sustainability of the global sand system in the Anthropocene

Sand, gravel, and crushed rock, together referred to as construction aggregates, are the most extracted solid materials. Growing demand is damaging ecosystems, triggering social conflicts, and fueling concerns over sand scarcity. Balancing protection efforts and extraction to meet society's needs requires designing sustainable pathways at a system level. Here, we present a perspective on global sand sustainability that shifts the focus from the mining site to the entire sand-supply network (SSN) of a region understood as a coupled human-natural system whose backbone is the physical system of construction aggregates. We introduce the idea of transitions in sand production from subsistence mining toward larger-scale regional supply systems that include mega-quarries for crushed rock, marine dredging, and recycled secondary materials. We discuss claims of an imminent global sand scarcity, evaluate whether new mining frontiers such as Greenland could alleviate it, and highlight three action fields to foster a sustainable global sand system.