The sand rush, after water the sand is the most exploited natural resource in the world. This over-exploitation may lead to major environmental, economic and social consequences. An April 2022 UN report thus called for urgent actions to avoid a “sand crisis”
What is sand exploitation?
The global demand for sand has tripled over the last two decades, now reaching 50 billion tons a year. It is expected to keep growing as sand is a key ingredient for concrete, roads, electronics and glass. The demand is also increasing due to growing urbanization and construction, especially in China (60% of the consumption) where artificial islands and buildings are absorbing huge amounts of concrete, therefore of sand.
Sand is mostly extracted from lakes, riverbeds and coastlines, where sharper grains and silica sand can be found. The methods of extraction depend on the location of the sand: backhoes, bare hands or shovels are used along rivers, meanwhile suction pumps and dredging boats are employed along coastlines and underwater.
Desert sand is unfortunately useless for construction as the grains are too small and smooth for binding in concrete. Meanwhile, the exploitation of marine sand is growing due to the depletion of land-based resources. However, the sea sand needs to be desalinated: the amount of fresh water required for this operation is huge and increases the environmental impact.
Major environmental consequences
These days, sand is consumed faster than it can be replaced, as natural processes take hundreds of thousands of years. The consequences of over-exploitation can already be seen in satellite images, showing coastlines and riverbanks erosion. They can be various and depend on the location and the methods of extraction: river channels may widen or narrow, sediment flows may increase or disappear and changes can happen suddenly or very slowly.
The most kown impact is coastal erosion. Current studies estimate that between 75 and 90% of the world’s beaches have shrunk. 25 Indonesian islands have already disappeared due to massive sand extraction. In the Mekong River, the digging of the delta (roughly 2 centimeters) has caused the salinization of fertile lands. The banks of the Mekong have become unstable and should they collapse, more than 500 000 Vietnamese would have to migrate.
But sand mining is also responsible for the destruction of biodiversity, changes in the chemical composition of waters or the sedimentation flows. Even worse, the effects of sand exploitation would probably increase the effects of global warming such as the rise of sea level.