What if... the world ran out of sand?

Sci-fi could become reality if our addiction to constructing in concrete continues unchecked.

At first glance it may sound like an odd question, but the fact is the world is running out of sand – or rather, the type of sand needed to make concrete – fast.

Sand found on beaches and in deserts is in plentiful supply, but unfortunately it is next to useless from a building perspective. Having been worn by the sea or by wind, it is too smooth to have much value as an aggregate. What the construction industry requires is river sand, which retains its sharper edges and therefore can be used to create the concrete upon which we have become so dependent. Such sand is in alarmingly short supply.

That we are in this situation should come as no surprise when you consider it takes 200 tonnes of sand to manufacture sufficient concrete to build a single home. Add to that the fact that India alone is forecast to build 90 million homes over the next 20 years and it is clear that the world has a problem. Some experts estimate that China, for instance, only has a year’s domestic supply of river sand left.

This is a massive problem, but one that is only just starting to be talked about in construction circles. That the industry has been slow on the uptake – or perhaps blind to the issue is more accurate – is all the more concerning given the impact the shortage is already having on geopolitics. There is now a substantial illegal trade in the material. Sand is being dredged out of rivers in poor countries, principally in Africa, and then illegally traded with development-hungry countries such as the US and, more extensively, China.

What next?

So, where do we go from here? For a start we need to stop gobbling up resources with such little regard for the consequences. As specifiers, architects must demand that building materials can either be replaced or reused. That means greater use of materials such as wood, but also specifying recycled steel and embracing other elements that make up the circular economy.

Sadly, I am not optimistic that the industry will change its ways. Experience tells me we’ll continue to feed our addiction to concrete no matter the cost. Our reaction to global warming, for instance, has largely been to slap a solar panel on a building rather than initiate genuine change.

However, talking to young people fresh out of architecture school gives me some hope. From an early age, they have been educated about environmental issues and consider the consequences of their actions in everything they do. The next generation might yet demand the change required. Let’s just hope it isn’t too late.