LONDON: It is no longer a cliche to say that the sands are shifting. They really are — by the lorryload.
According to a UN report published last week, sand is being mined, dredged and even stolen to satisfy the global appetite for infrastructure. Strikingly, sand comes second only to water in terms of the volume of natural resources that are extracted and traded globally.
While it is being poured into much-needed urban development, particularly in China and India, sand is not a limitless gift of nature. The world has a “sand budget” and we are spending it faster than it can be replenished.
The environmental consequences are becoming plainer by the day. The plunder of lakes, rivers and coastal areas reduces biodiversity, destroys fishing communities, causes pollution, lowers the water table and, by ferrying away natural deposits, increases flood risk.
It can also threaten tourism in countries like Morocco: With illegal coastal extraction providing half of the country’s annual sand needs (10 million cubic metres), beaches are in danger of being stripped back to rock.
“It is time to challenge the paradigm of infinite sand resources,” concludes the UN report.
It calls for improved governance on an issue that cuts across other sectors, such as mineral extraction, coastal management, water management and biodiversity.
It also urges international monitoring and understanding of how geological and hydrological forces move sand and gravel from one place to another — and so identify where material is being lost.
USED IN CONSTRUCTION AND DEVELOPMENT
We tend to think of sand as the powdery stuff that slips between the toes. In fact, it falls into two main classes.
The first is mineral sand, which contains such minerals as zircon and is used to make ceramics and pigments. It comes mainly from river beds and coastal areas like beaches. In inland and non-tropical coastal areas, sand is mostly made up of silica, or silicon dioxide.
The second class is aggregates, a generic term for crushed rock, sand and gravel. This easier-to-bind, coarse variety of “sand” is coveted by the construction industry.
Up to 50 billion tonnes is removed from rivers, pits, quarries, coastlines and marine areas each year. Developing economies with rapidly growing infrastructure are voracious consumers of aggregates: China is home to more than 58 per cent of global cement production.
Illegal or unregulated sand extraction flourishes in countries where, variously, rules are lacking, enforcement is lax or corruption thrives.
Dr John-Paul Latham of Imperial College London points out that because transporting sand is so expensive, the material is generally used near to its source. Tracking where infrastructure is springing up can yield clues about which ecosystems might be targeted.
“There’s a huge incentive to get hold of the stuff by hook or by crook, and that can put a strain on nearby riverbeds and even flood plains,” Dr Latham explains.
Quite subtle discussion needs to be had on how to reconcile that desperate demand for growth with the threat to local environments.
The great sand drain also presents a technical challenge, he says, to come up with alternative materials, perhaps using desert sand:
It is a huge resource that is already on land, so removing it is arguably less of an environmental problem. The concrete industry needs to look at this.
An Imperial student start-up, Finite, is trying to develop a building material out of smooth, fine-grained sand; the reusable, biodegradable composite is currently only suitable for temporary structures.
Sand is becoming a geopolitical irritant too. China’s territorial expansion in the South China Sea depends on imported aggregate. Sand is now the stuff of empire.