A new perspective published on 2 July in Nature sheds light on the over-exploitation of sand resources, which is damaging the environment and communities, promoting violent conflict, and leading to shortages (1). Therefore, the authors from the US and UK highlight a need for global monitoring and management of this important resource.
From our homes to the glasses we drink from and the computer we use, sand is a “key ingredient of modern life.” But little is known about how it is mined and how much we use, according to Bendixon and colleagues. And rapid urbanisation and population growth are fuelling further demand for sand resources and driving unsustainable exploitation.
Around 32 billion to 50 billion tonnes of sand are used globally each year, the authors write, mostly for concrete, glass, and electronics — its usage now exceeds the rate of natural renewal. However, current international sand-trade databases do not distinguish between sustainable and unsustainable sources of the stuff. Active sources can cause great environmental, social, and economic harm.
Sand suitable for industry mainly comes from rivers since grains from the desert are too smooth. However, extracting sand and gravel from rivers can have serious implications on local ecosystems, as well as the 3 billion people living along riverbanks around the world.
For example, collapsing riverbanks along the Mekong River in Vietnam as a result of sand mining will displace nearly 500,000 people in the near future, the Vietnamese government estimates. And eroding riverbanks along the Ganges are destroying the habitats of many species, including the endangered gharial crocodiles (Gavialis gangeticus).
Moreover, a lack of regulation surrounding sand mining has led to the establishment of local ‘sand mafias’ in developing countries where demand is highest — in low-income countries, the sand industry is “small and informal”, and therefore, difficult to monitor.
The authors outline seven components that are crucial to achieving sustainable extraction:
- Use of sustainable sources of sand with less ecological impact and those that do not damage rivers.
- Greater use of alternatives, such as crushed rock, industrial slag and waste including copper, fly ash and foundry sand, and recycled plastic. This will require new laws governing concrete disposal and perhaps, financial incentives to encourage reuse or the use of sand alternatives.
- Reuse of sand materials, where possible, for example, demolition waste can be used for roads and foundation.
- Reducing the amount of concrete in new structures to decrease the use of sand. This would require the use of more efficient building materials, such as concrete blocks, and making appropriate changes to industry standards.
- An international or multilateral framework to regulate and control sand extraction. As a first step, the authors urge the United Nations Environment Programme (UNEP) and the World Trade Organization (WTO) to establish global good-practice guidelines for sand extraction.
- Education on issues related to sand mining — spanning all sectors from schools to policy advice and media coverage — along with solutions to existing problems.
- Monitoring the use of sand by means of a global programme to gather and share data. This could be achieved by making use of remote-sensing technologies and sharing the data globally.
(1) Bendixen, M. et al. Time is running out for sand. Nature (2019). DOI: 10.1038/d41586-019-02042-4