Increasing demand for the world’s most-used natural material, sand, is fuelling mining in fragile natural habitats and prompting a growing number of countries to ban exports.
The construction industry’s use of sand, gravel and crushed rock outstrips total global consumption of all fossil fuels and metals combined, when measured by weight, according to the OECD. It forecasts that in the next four decades construction demand for sand and gravel will almost double to cater for the world’s growing population and rising living standards.
“Emerging economies are playing catch-up. They need [sand] to build infrastructure, roads and houses,” said Jean Chateau, senior economist at the OECD. “There’s absolutely no substitute. You need rocks and sand to build the world. You cannot build a world in plastic.”
The sheer scale of sand and gravel extraction is creating what the UN Environment Programme has called “one of the major sustainability challenges of the 21st century”.
“The amount of infrastructure coming down the pipeline for urbanisation is so gargantuan that unless there are sustainable solutions . . . [sand mining is] going to have more and more of an impact on our rivers and coastlines,” said Richard Lee from conservation organisation WWF.
One of the main ingredients of concrete is sand; the other is cement.
China is by far the largest producer of cement in the world. In the three years to 2014 it produced more cement than the US did in the entire 20th century, according to the US Geological Survey.
And that means China is using a lot of sand, too. China’s Poyang Lake is thought to be the largest sand mine operating in the world. According to one academic study, miners are estimated to have extracted 236m cubic metres of sand per year in just a two-year period, dramatically changing its shape.
Around the world, about 28bn tonnes of sand is extracted each year, according to the OECD.
But this may be an underestimate. Research cited in a recent UN report estimated that one tonne of cement can require up to 10 tonnes of sand to make concrete. Globally, 4.1bn tonnes of cement is produced each year, according to the US Geological Survey. This implies that the construction industry could be using more than 40bn tonnes of sand each year.
The disparity between the two figures demonstrates how opaque the supply chain is, environmental campaigners say.
“[Trade] is really difficult to track,” said Dave Tickner, chief freshwater adviser for WWF. “We know who’s digging this stuff out . . . and where it ends up, but we don’t know what happens in between. It’s a complete black box.”
Many of the world’s largest cities are located on the edge of water. As they expand, land reclamation is increasingly being used to extend cityscapes into the seas and oceans, requiring huge volumes of concrete, and, therefore, sand.
By far the greatest demand for sand for land reclamation comes from Singapore, which has extended its land mass by almost 25 per cent since 1965. Its local geology lacks places to extract sand, and the city relies on neighbouring countries such as Malaysia and Cambodia for supplies.
Growing demand means a growing trade.
Although Singapore’s sand imports continue to rise, dwarfing those of any other country, demand for foreign sand is also increasing elsewhere. Belgium, the Netherlands and France are among the world’s largest importers of sand, while some of the biggest increases in imports came in countries with substantial population growth.
Bahrain imported more than 570,000 tonnes of sand last year according to UN Comtrade data, the largest amount on record. India imported more than 520,000 tonnes of sand in 2018, up from an annual average of about 50,000 tonnes in the eight years previously. Thailand’s sand imports have also shot up in the past few years.
As demand mounts for sand, a growing number of countries, mostly in south-east Asia, are seeking to protect their resources by banning or significantly restricting exports.
Indonesia banned marine sand exports in 2003 and four years later extended this ban to include sand extracted from land and rivers, too.
Vietnamese miners were instructed to stop exporting sea sand in 2010.
Cambodia brought in a temporary ban in 2016 and then fully banned exports in 2017.
Malaysia was the first to introduce a ban, as early as 1997, but it was lifted in 2015. Then, after almost 55m tonnes of sand made its way to Singapore in 2018, the Malaysian government reintroduced the ban earlier this year.
Mahathir Mohamad, Malaysia’s prime minister, has complained of sand miners “digging up Malaysia and giving her to other people”.
Hard to enforce
The sand trade is hard to monitor and regulations have proved difficult to enforce. The industry’s entry barriers are low — all an aspiring sand extractor needs is a team of diggers with handheld tools and a truck.
This means that official sand exports data are regarded with scepticism by some environmentalists.
For example, in the decade to 2016, UN trade data showed that Singapore imported more than 80m tonnes of sand from Cambodia. But only 2.8m tonnes of sand were recorded leaving Cambodia for Singapore over the same period.
“So much sand mining is informal,” said Mr Lee. “This is part of the challenge. It’s really hard to figure out what’s going on in any one situation.”
Rising demand for sand means it is becoming increasingly urgent for some countries to develop alternatives, say environmentalists. Few materials are as cheap and readily available, but the recycling of old construction materials could help reduce demand, while cities could be designed in a way that reduces the need for concrete.
The problem is becoming pressing. As cities expand, less local land is available to supply sand.
Jason Willett, a construction aggregates commodities specialist at the US Geological Survey, said: “We can’t run out of rock, but we can run out of places where we can mine the rock.”