Global sand demand: unprecedented extraction rates could lead to shortage

Up to 50 billion tonnes are excavated annually for use in road-building to water purification

Construction at a Chinese-funded $1.4 billion land reclamation project in Colombo, Sri Lanka AFP

It is the most precious natural resource you have probably never thought of, second only to water in annual tonnage consumed.

But today, the use of sand and gravel in everything from construction to water purification has reached unprecedented levels, prompting global concern.

Annual demand for sand, the single most extracted material on the planet, is running at an estimated 40 to 50 billion tonnes globally – triple the level of just 20 years ago.

Now a new report from the United Nations Environment Programme has warned that such consumption poses “one of the major sustainability challenges of the 21st century”.

The study - called Sand and Sustainability - calls for urgent action to reduce demand, which is projected to double by 2060, propelled by population growth and economic expansion.

With everything from rhinos and gorillas to trees and bees now the focus of conservation drives, an apparent call to “save our deserts” may sound bizarre.

Yet the image of dune-filled expanses has helped conceal the fact that sand is being consumed far faster than it can be replenished, and its extraction is already inflicting serious environmental damage.

Ironically, desert sand is not the focus of concern, as it’s typically too smooth and fine for use in construction. That explains why a nation such as the UAE, which borders the vast Arabian Desert, has to import $500 million of sand and gravel each year.

The real concern is that sand’s “cheap and limitless” reputation has led to cavalier extraction methods which now pose a serious environmental threat because demand soars.

The principal sources of sand and gravel are quarries, pits, rivers and coastlines – all of which have affect their local ecosystems.

Because of the cost of transporting it, most of the material is consumed relatively locally. But the growing mismatch between demand and availability is putting huge pressure on natural habitats in some regions.

The UN report highlights China and India as critical hot spots for unsustainable sand extraction from rivers, lakes and coastlines.

Following the iron law of economics, increasing demand and limited supply has boosted prices – and created a growing black market for sand and gravel.

Investigations by the Times of India have charted the rise of a so-called "sand mafia" running smuggling operations involving tens of thousands of trucks carrying more than two billion dollars' worth of illegally extracted sand from Tamil Nadu.

According to the UN report, about half of the construction sand used in Morocco comes from illegal coastal extraction.

Sand smugglers have turned much of the sandy beach along the country’s western coast into a rock-strewn wilderness. Ironically, the stolen sand is often used to build coastal tourist resorts.

The soaring price of sand has prompted some outrageous acts of eco-vandalism. Pascal Peduzzi, one of the authors of the UNEP report, told Science magazine that one fishing village in Jamaica had its entire beach stolen one night by an armed gang who took it away in trucks.

The illegal trade in sand is exacting a price on its perpetrators. Last month, two thieves were killed after being buried alive by the collapse of a riverbank they were raiding in the east Indian coastal region of Andhra Pradesh.

International laws or trade controls to prevent illegal sand extraction could take years to enact. But, says the UNEP report, even where extraction is legal it often comes “at the expense of other economic sectors, local livelihoods and biodiversity”.

Instead, the report identifies strategies to tackle the emerging crisis.

It calls for increasing use of alternative building materials such as fly ash concrete – a by-product of waste incineration – and palm kernels and coconut shells instead of aggregate. Non-toxic municipal waste has already been used in India as a replacement for aggregate in road-building.

More recycling of concrete waste would also help. According to the report, Germany already recycles almost 90 per cent of its waste aggregates.

Another strategy calls for the reuse of existing building stock rather than demolishing it – and greater efforts to cut back on speculative construction projects.

Perhaps most radical of all is the proposal to bring illegal extractors into the fold. This involves offering them the right to work at new sites whose suitability has been identified by government agencies.

It’s not ideal, but it’s better than leaving it to the sand thieves to decide where they are going to operate.

“Sand is used by everybody”, said Mr Peduzzi. “We are not here to halt the sector, but work together with all stakeholders on sustainable solutions.”

Robert Matthews is Visiting Professor of Science at Aston University, Birmingham, UK