A thirst for sand.

From islands concrete is born.

Counting the grains of sand at the seaside seems like an insurmountable feat. For now. But in recent years, sand has actually come to be one of the scarcest commodities on the planet, although this has hardly been brought to the attention of the general public. The reason for the decline in this resource can be traced back to the fact that we need staggering amounts of it to make concrete. We look back at the story of this tragic disappearing act.

Forgotten after the Middle Ages and not rediscovered until around 1700, concrete came to be the construction material of our time thanks to continual improvements and developments. For some 150 years now, we have been mixing sand with cement to create concrete and then adding steel. This gives us reinforced concrete, which is fundamental to our whole modern infrastructure and defines the skylines of our towns and cities.

The two-thirds principle.

How much sand?

City, sand, surplus?

Experts estimate that we currently use more than 15 billion tonnes of sand around the world every year. The United Nations Environment Programme (UNEP) puts the figure even higher, suggesting that sand is being mined globally at a rate of some 40 billion tonnes a year. In Germany alone, 235 million tonnes of sand and gravel were extracted in 2012, with 95 per cent of that volume going straight to the construction industry. 
This ridiculously high figure is pretty much beyond our grasp. But it’s time for us to start thinking about what it really means because this insatiable thirst for sand comes with some serious consequences.

All of the easily and cheaply accessible sources have now been cleared out. And industry experts are predicting that demand is set to keep rising. So where does all the sand come from? Having dredged rivers (which led to intensified flooding) and mined sand pits (which did not go down well with landscape conservationists), attention has now been turned to the bottom of the sea.

The wounds run deep

But the sea is no easy solution either. The huge nozzles on the suction machines don’t just selectively take up sand – creatures and plants living on the seabed are caught up, too. Marine biologists are trying to warn us about the repercussions of this. After all, the wildlife at the bottom of the sea is a crucial part of the underwater food chain, guaranteeing the survival of so many other species. As if that wasn’t enough, the dredgers are causing even more damage. Clouds of sand dust are being kicked up and spreading out for kilometres around the dredging sites. The sediment then settles somewhere else, burying the organisms living on the seabed there. Marine biologists in Saudi Arabia witnessed an entire reef dying off as a result of sediment displaced by sand extraction covering the coral. Elsewhere, algae and seaweed – both essential to maintaining oxygen levels – are being smothered. And, you guessed it, the implications of this are far-reaching, too.

From sediment to an empty fishing net.

As living conditions worsen, the lifeforms move on. But because microorganisms represent the source of food needed by the bigger fish, their very existence is then thrown into question, too. And so they leave the affected area. At the end of this chain, we have the fishermen who return with empty fishing nets. At this point, the problems at the depths of the ocean reach land.

‘The idea that sand is a quickly renewable resource is a dangerous misconception. It is simply not true.’

Kay-Christian Emeis

Director of the Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research

The sea puts up its defences.

Estimates indicate that there are several thousand dredgers working to extract sand under the sea around the globe. Depending on the machine and the location, up to 400,000 cubic metres can be gathered by each dredger, every single day. If we want to see how the sea responds to this intervention, we don’t have to go as far afield as the Arabian Peninsula. In fact, we need look no further than the North and Baltic Seas here in Europe. Geologists at the University of Kiel are conducting research into the long-term repercussions of sand extraction. What they have found is that there doesn’t seem to be any general rule that applies when it comes to the ability of coastal regions to regenerate. Some regenerate, others don’t. But what are the effects of the holes that are created on the ocean floor? How does the sea try to fix the wounds we inflict upon it?

When sand is removed, a natural reaction is triggered involving the currents, waves and gravity. The sand in the surrounding area is moved in such a way that the holes left behind are refilled. For this to happen, though, sand is being washed away from the beaches. So, in other words, extracting sand in this way is having a drastic impact on nearby coasts and islands. Our coastlines are being altered and, in the worst case, a whole island could even disappear entirely.

The removal of sand robs us of our beaches.

Sand has come to be one of the most sought-after resources in the modern world. And there are too many instances of it inciting criminal activity. It is estimated that to date 40 to 45 per cent of sand around the world has already been stolen. Underpaid workers keen to secure their minimal income are emptying out bucket after bucket of sand from the beaches and supplying it to ruthless, unethical building contractors. What is left behind, as we have already seen in Morocco, is bare rock. At this stage, regeneration is more or less impossible, as there is simply no sand to be pulled back into the sea.

If we carry on the way we are going, there is a good chance that beaches as we know them will cease to exist by the end of the 21st century. It’s high time we start to change our mindset and look for alternative approaches. The way we use finite resources has to stop, and alternatives to the construction material that has caused this immense thirst for sand must be found. But wait. We’re one step ahead. We’ve already found the alternative we need: wood.

‘If we can make people understand what is at stake here, make them realise just how important every single grain of sand on our beaches is and just how essential the beaches are to our lives and general existence, then there may be hope yet.’

Gary Griggs

Marine Researcher at the University of California in Santa Cruz

Sources:
www.handelsblatt.com: ‘Raubbau an einem wichtigen Rohstoff – Sand wird zur Schmuggelware’ (Overexploitation of a key resource – sand becomes contraband)
ARTE: Sand – Die neue Umweltkatastrophe (Sand – the latest environmental catastrophe)