A global sand crisis threatens to unfold before our eyes, researchers warn.

You may not think about it every day, but you owe a lot to sand. It is in the concrete on which your house rests and in the glass that shows off in your window frames. Sand is therefore a crucial building material. And you would expect us to be careful with that. But nothing could be further from the truth, researchers write in the magazine Nature Sustainability† Humanity is working hard to exhaust the sand reserves worldwide and the tide does not seem to be turning immediately; in the coming decades, the demand for sand will only increase.

Increase

Between 2020 and 2060, the demand for building sand will increase sharply, especially in low-income countries, the researchers write. For example, the demand for construction sand in West and East Africa is expected to be 500 percent higher by 2060 than it is now. And also in India and South Asia, the demand for construction sand is expected to increase sharply in the next four decades; by 294 and 269 percent respectively. Meanwhile, demand in high-income countries is declining somewhat, but globally, the researchers expect that demand for construction sand by 2060 will still be 45 percent higher than it is now (and that is still a conservative estimate).

Exhausted

It’s worrying. Because we are already depleting sand stocks much faster than they can be replenished (see box).

When you’re walking on the beach, a shortage of building sand may seem like a far-from-your-bed show. But the sand that you find on our beaches is not immediately suitable as building sand. It is in fact too round; In construction, people prefer to work with ‘angular’ sand, which you will find deeper inland, in the rivers, as coastal researcher Matthieu de Schipper explained to Scientias.nl a few years ago. Sand is created by large rock fragments breaking off at the top of the river. And those stones are ground further and further as the river carries them along.” This creates grains of sand, which – the longer they are on the road – become more and more round in shape. If we let the river run its course unhindered, it eventually delivers almost round grains of sand to the coast. And so the well-known beach is created. “Without rivers, no beach.” But, as mentioned, construction is mainly interested in angular sand. And so in some places the sand is fished out of the river in time – long before it reaches the coast. This is nothing new: it has been happening for years. However, the amount of sand required by construction has exploded in recent decades. “We are currently extracting more sand from the rivers than the rivers can produce,” concludes De Schipper.

And that has far-reaching consequences. “Overexploitation of sand has led to ecosystem destruction,” said study researcher Xiaoyang Zhong. In rivers where more sand is removed than is created, the animals that live in that sand are stripped of their homes. “In addition, the disturbance of sediments can affect the clarity of the water, which in turn has major consequences for the animals and plants that live in it.” In addition, the sand extraction that has gotten out of hand leads to erosion of coastlines; sand that is on its way to the coast, but is removed from rivers prematurely, never reaches the coast and therefore the beach is not replenished. But the impending shortage of building sand also has other consequences. For example, illegal sand is increasingly being extracted and traded. “Social impacts include (…) an increase in corruption and crime,” Zhong said.

More construction

And now Zhong and colleagues predict that the demand for sand will increase considerably in the coming decades. “At first glance, that future demand could be quite surprising,” says Zhong. After all, it concerns enormous amounts of sand. “But when you then realize how much infrastructure and houses still need to be built (in particular in low-income countries, ed.), it is no longer surprising.”

Halve the question

The increasing demand for construction sand may not be very surprising; this one is worrisome. But we are not completely powerless, Zhong and colleagues write in their study. For example, it should be possible to halve future demand simply by working less with building materials that require construction sand – such as concrete – and by recycling more materials. “I do think that there will always be a high demand for sand,” says Zhong. “But what we can do is take measures to reduce that demand, for example by choosing alternative building materials where possible, adapting building designs and extending the life of structures and reusing concrete where possible.”

Difficult crisis

It is certainly not the first time that researchers have warned us about a global sand crisis; in recent years they have repeatedly confronted us with the hard figures and facts. And some governments have also taken measures, Zhong says, but it appears to be not so easy to protect sand stocks. “For example, the Chinese authorities have banned sand mining in the Yangtze River, but sand miners have simply moved to other regions.” Other governments do not (yet) see the sand crisis as a real problem and are not taking any measures at all. In addition, illegal sand extraction – especially in third world countries – remains a major problem. People often know that they are not allowed to just get sand from rivers, but they do it anyway – because of the enormous amount of money they can earn this way.

It is not entirely clear how long we can continue on this path. “Researchers don’t know exactly how big the worldwide sand stock is,” says researcher Paul Behrens. There is also an important task for researchers, says Zhong. “We need to have better estimates of the total available sand stock and we need to start measuring sand extraction worldwide.” Pending hard figures, however, according to the researchers, there can be no doubt that a sand crisis is imminent. “All over the world, easily accessible sand is disappearing at an alarming rate with serious consequences for the ecosystem,” said Behrens. “Better governance and planning are needed to ensure there is enough sand for future generations.” Only in this way can it be prevented that it will have another crisis on its plate.