Recent reports have raised concerns over the Covid-19 vaccine supply, due to a shortage of high-quality sand – the main ingredient in the billions of glass vials needed to transport those precious doses. On the face of it, this might seem the most easily resolved stumbling block of the whole vaccine drive. Sand, after all, is almost a synonym for ubiquity.
But the challenge of securing the right sand for those vials (which require a pure form of silica sand) points indirectly to a deeper problem with large-scale sand extraction. Sand is the world’s second most-used raw material after water and, by volume, its extraction makes up 85 per cent of all mineral mining.
Currently, there are supply concerns over the industrial-grade silica sand needed for the vaccine vials but it’s hardly that we’re running out of sand. Most deserts, after all, are full of the stuff. However, the rounded grains of windblown desert sand do not bind well in the concrete which accounts for the vast majority of sand (and gravel) use. Instead, sand is often dug from fragile rivers, beaches and the seafloor in such huge quantities that it is creating major environmental and social impacts – kicking up silt that smothers fisheries, accelerating coastal erosion, being controlled by criminal gangs and even triggering diplomatic tensions between countries.
Sand, in its many varieties, is a component in numerous materials that we take for granted, from construction to cosmetics, from food to electronics. When mixed with gravel and bound with cement, sand becomes concrete. When mixed with bitumen, sand becomes asphalt. When heated, sand becomes glass, and when pumped from the seabed in vast quantities it becomes the reclaimed land used to expand sprawling coastal cities like Singapore, Dubai and Hong Kong. It is no exaggeration to state that sand and gravel constitute the backbone of the modern world.
Sustainably managing this natural resource will become increasingly critical as we transition to clean, renewable energies (wind farms and solar panels both need sand) and work to meet the Sustainable Development Goals. Improving the way that we use this vital resource has three main dimensions.
The first is to get a better handle on how much we even use every year. Estimates are usually based on proxies like cement sales. Using back-of-envelope calculations, the UN estimates that global sand consumption may be in the region of 50 billion tonnes a year. This is enough to build a wall 27-metres high and 27-metres wide around the earth, every year. Given that this covers one use for one type of sand, it is most likely an underestimate.
Over the past 20 years increasing sand demand has been largely driven by explosive growth in China. But other countries such as India and Indonesia have rapidly urbanising populations and are entering a period of increasing demand for sand. Some experts estimate that roughly two-thirds of the roads, airports, train lines and buildings that will exist in 2050 have not yet been built. Meanwhile, rising sea levels and fiercer storms triggered by climate change may require thousands of miles of new concrete sea walls. New technologies such as satellite-based earth observation are powerful tools to build up a picture of the movement of sand across huge areas, but this needs to be combined with mapping at local levels to complete the picture.
The second priority is to reduce the negative impacts of sand mining from “active systems”. Sand is a bulky, heavy material, cheap but expensive to transport, which means that sand is normally mined close to where it is needed. Sand extraction runs a spectrum from a poor artisanal miner with a shovel and wheelbarrow to enormous off-shore dredgers that can process up to a hundred thousand tonnes of marine sand a day. It can be dug either from non-active ‘fossil’ systems such as inland sand deposits in quarries or from “active” sediment systems such as riverbanks, beaches or the seabed where it can cause local environmental devastation, downstream siltation and coastal erosion.
The third priority is to encourage cooperation over viable technologies and approaches that can help the sand sector become more sustainable. On the positive side, there are many innovative ideas to share: new ways to recycle old building materials; additives that could make desert sand usable at scale; designs that reduce the amount of concrete in buildings, and so on. No single technology or approach provides a magic solution, but there is much out there to learn from. Such is the scale of our sand use, that even improving its performance at the margins could have enormous benefits for people and planet.
Oli Brown is an associate fellow with the Energy, Environment and Resources Programme at Chatham House
Dr Louise Gallagher is the environmental governance lead for the Global Sand Observatory Initiative
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