Tracking five decades of global sand and gravel stocks and flows in 184 countries

Abstract

Sand and gravel, providing essential physical foundations for modern societies, are facing increasing demand due to urbanization and rural construction. This surge stems from the widespread use of these materials in building, roads, and other infrastructure, which has raised increasing concerns about the “sand crisis” and environmental damages from overexploitation. Addressing such concerns requires understanding patterns of global and national sand and gravel cycles, yet this remains hitherto unexplored. Here, we quantified historical stocks and flows of sand and gravel in buildings and infrastructure in 184 world countries from 1970 to 2019. We show that global gravel consumption is more than twice that of global sand consumption, albeit with a more stable growth rate. However, in international trade, sand dominates, with trade volumes 1.9 times larger than those of gravel, and Singapore is the leading importer. This suggests that sand supply is more vulnerable to geopolitical and market fluctuations. Over the past decades, per capita sand in-use stocks have increased in nearly all countries, whereas per capita gravel in-use stocks have saturated or even declined in many industrialized countries. Asia accounted for half of global sand in-use stocks and China has a large share of gravel stocks in residential buildings, both reflecting the impact of urbanization mode. These insights can inform policies for securing sustainable aggregate supply chains, improving resource efficiency, and mitigating environmental risks associated with overexploitation.