Aurora Torres, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany, Jianguo Liu, Michigan State University, East Lansing, MI, USA, and colleagues have summarized the ecological consequences of our tremendous hunger for sand. Sand is used by the construction industry, especially for the rapid expansion of cities, and as a raw material for glass, semiconductors in computers, solar cells, and other technologies. Sand and gravel are the most extracted group of materials worldwide, exceeding fossil fuels and biomass.

Sand is abundant only at first sight. It is not a fast-growing resource and not every sand is suitable for use. Sand from the desert, e.g., is not suitable. Many once rich deposits are already exploited or overexploited. Denser populations in coastal regions, rising sea levels, and increasing erosion mean that many sand deposits have disappeared.

To date, no one knows exactly how much usable sand is available worldwide. There are no international agreements, guidelines, or controls that could lead the exploding demand into regulated channels. Shortages and high profits are increasingly leading to political conflicts, crime, and violence. As a result, sand scarcity is an emerging issue with major socio-political, economic, and environmental implications.

The researchers are urgently asking for a real budget of the global sand resources, as well as an analysis of the hidden costs of sand extraction and trade. It is only on this basis that a sustainable and equitable use of this valuable resource is possible in the long term.

• A looming tragedy of the sand commons,
  Aurora Torres, Jodi Brandt, Kristen Lear, Jianguo Liu,
  Science 2017.
  https://doi.org/10.1126/science.aao0503