How overexploitation of sand is threatening ecosystems and livelihoods

Found on beaches, in rivers, across deserts and on the seabed, sand has long been seen as abundant and virtually inexhaustible. But it has become the world's second most exploited natural resource after water, and scientists warn rising demand will cause "enormous environmental damage".

From concrete towers and motorways to glass, microchips and cosmetics, modern economies depend on sand. Yet the vast scale of sand extraction remains largely ignored, despite mounting concerns among scientists over its environmental and social consequences.

According to the latest report from the United Nations Environment Programme (UNEP), nearly 50 billion tonnes of sand are extracted worldwide every year, and demand for buildings is expected to rise by 45 percent by 2060.

"To give an idea of the scale, it would be equivalent to building a wall 27 metres high and 27 metres wide that circles the entire Equator every year," says Pascal Peduzzi, director of GRID-Geneva, UNEP's environmental data centre. "You cannot extract that much material without causing enormous environmental damage."

Warnings of a sand shortage may seem counterintuitive. But not all sand is suitable for construction.

Desert sand, shaped by wind erosion, is too fine and too smooth to bind effectively in concrete. The construction industry instead relies on angular grains found in quarries or produced by the erosion of glaciers, rivers and coastlines.

As a result, extraction is concentrated in riverbeds, estuaries, coastal zones and shallow seabeds – areas that also play a vital role in maintaining ecosystems.

Six bn tonnes of sand extracted from world's oceans each year: UN

Damage beneath the surface

Sand performs essential functions in nature. It filters water, stabilises rivers and provides habitats for countless species, from crabs and turtles to birds and other wildlife.

"If you dig into a riverbed, you change its shape," says Peduzzi. "That alters how water flows."

The consequences can include increased flooding, drought, falling groundwater levels and the degradation of aquatic ecosystems.

Scientists also warn of implications for food security. Excessive extraction can increase water acidity, reducing soil fertility and making farmland less productive.

In some regions, the problem is already visible. Researchers have documented rising saltwater intrusion in major rivers, particularly in the Mekong Delta, where millions depend on fresh water for cultivating rice.

"With rising sea levels and riverbeds being lowered through sand dredging, the Mekong is becoming increasingly saline," says Nelo Magalhaes, an economist and environmental historian.

A similar process has been observed in France's Loire River since the 1970s, although the impacts are now far more pronounced in Southeast Asia.

At sea, industrial dredging vessels pose another threat. By scraping the seabed, they destroy microscopic organisms that form the foundation of marine food chains. Fishing communities are already feeling the effects.

"In parts of Africa and Southeast Asia, beaches have been stripped down to the bedrock," says Peduzzi. "Virtually every major river system in Asia has been affected by large-scale sand extraction."

Sand also serves as a natural barrier against rising sea levels. As beaches are depleted, coastlines become increasingly exposed to erosion and flooding linked to climate change.

Small island states are among the most vulnerable. In places such as the Maldives, scientists say the consequences are already becoming apparent.

"Today, we can directly link the disappearance of some beaches to overconsumption of sand," Peduzzi says.

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Cheap, yet valuable

The problem is often associated with developing countries, but Europe and North America are also major consumers of sand.

Researchers have documented large-scale river dredging across industrialised nations since the 1960s.

"When river levels fall, extraction intensifies," says Magalhaes. "That alters river profiles, damages ecosystems and destroys spawning grounds where fish lay their eggs."

The growing scarcity of suitable sand is also fuelling political tensions.

"There's a paradox," says Grégory Salle, a social scientist at France's National Centre for Scientific Research. "Sand is both a cheap, ordinary resource and, in some places, an increasingly valuable one."

That value has led to disputes over access and supply. While unlikely to trigger conflicts on the scale of those linked to oil or water, sand has already become a source of diplomatic friction in Southeast Asia.

Singapore, which has expanded its territory through land reclamation projects, imports vast quantities of sand from neighbouring countries. The trade has generated tensions with countries including Cambodia, Vietnam and Malaysia, alongside allegations of environmental destruction and illegal trafficking.

Elsewhere, sand provides profits for organised crime. In countries such as India, Kenya, Morocco and Colombia, illegal networks known as "sand mafias" control parts of the trade.

Because sand is relatively easy to extract, enforcement is often weak and corruption widespread.

"People investigating these activities can face serious risks," says Peduzzi, citing cases involving violence and intimidation linked to illegal mining operations.

In Morocco alone, an estimated 40 to 50 percent of sand extraction is believed to occur illegally.

Overlooked resource

Experts disagree over whether the world is facing an actual shortage of sand.

UNEP argues that extraction has already exceeded the natural replenishment rate of some deposits.

China illustrates the scale of modern consumption. The country uses more than half of all the sand extracted globally and consumes around 33 times more than the United States each year.

Others urge caution. Magalhaes argues that vast reserves remain available, particularly offshore. The issue, he says, is not the imminent exhaustion of supplies but the increasingly destructive methods required to obtain them.

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Ultimately, the debate goes beyond sand itself and raises broader questions about economic development and consumption.

Recycled concrete, alternative building materials and more sustainable construction practices are frequently proposed as solutions. But for some researchers, such measures will only go so far unless accompanied by a deeper reassessment of growth-driven models of development.

UNEP is now calling for stronger global governance of sand resources, including national inventories, improved monitoring and recognition of sand as a strategic material.

Yet when the European Commission recently published its list of critical raw materials, sand was notably absent – a sign, perhaps, that the world's dependence on this seemingly ordinary substance has yet to fully register among policymakers.

This article was adapted from the original in French by Claire Laville.