Aurora Torres, Jodi Brandt, Kristen Lear and Jianguo Liu
Between 1900 and 2010, the global volume of natural resources used in buildings and transport infrastructure increased 23-fold (1). Sand and gravel are the largest portion of these primary material inputs (79% or 28.6 gigatons per year in 2010) and are the most extracted group of materials worldwide, exceeding fossil fuels and biomass (2). In most regions, sand is a common-pool resource, i.e., a resource that is open to all because access can be limited only at high cost. Because of the difficulty in regulating their consumption, common-pool resources are prone to tragedies of the commons as people may selfishly extract them without considering long-term consequences, eventually leading to overexploitation or degradation. Even when sand mining is regulated, it is often subject to rampant illegal extraction and trade (3). As a result, sand scarcity (4) is an emerging issue with major sociopolitical, economic, and environmental implications.