UN environment: world needs to ditch sand addiction

Sand and gravel are literally ingrained in our society. From bridges, roads, houses and windows to solar panels and computer chips, humans use on average 17 kg of sand every day, with little regard to its impact on the environment.

It’s the world’s second most exploited resource, after water, and yet we don’t keep track of how we use it, according to a new report by the UN Environment Programme (UNEP) released on Tuesday.

Sand is made of tiny fragments of rocks that have weathered over thousands and even millions of years. At 50bn tonnes of sand extracted every year, humans are using up the abundant yet finite resource at a faster rate that it can naturally replenish.

Demand for sand in Asia has been the fastest growing so far, with China now accounting for over half of its use worldwide. In Africa, where population is expected to double by 2050, development needs for sand to build essential infrastructure will keep increasing.

The report, authored by UNEP’s Global Resource Information Database (GRID) in Geneva, lays out a series of steps countries should take to make sure the valuable mineral resource is sustainably managed.

Pascal Peduzzi, director of GRID-Geneva – who has overseen all of the centre’s previous publications on sand, earning him the nickname “Sandman” among his colleagues –, told Geneva Solutions why countries must start anticipating and mapping out the precious mineral.

GS News: If we’re extracting sand more quickly than it can naturally be replaced, do we know how much damage has already been done to ecosystems?

Pascal Peduzzi: The impact will depend where the sand comes from. We should differentiate two types of situations. One is when you're taking sand from where it is static in the environment like in quarries, or from crunching rocks, because there the sand and gravel are not interacting too much with the rest of the environment. You still have an impact on the landscape but you can mitigate those impacts and make sure that it is done in the right way. When you take sand from a dynamic area – rivers, beaches or marine areas – that is a totally different game because the sand and gravel play a role in the ecosystem. They are part of the habitat, they support biodiversity, and protect the shorelines against storm surges or salinisation of aquifers.

If you remove sand from marine areas, you're sterilising the bottom of the sea, killing all the microorganisms that small fish feed on, which in turn bigger fish feed on. When you take sand out of rivers, you change the river flows, leading to further floods or droughts. Erosion of the riverbanks changes water turbidity, again having an impact on flora and fauna, so on fisheries and water quality. In many semi-arid areas, where rivers are seasonal, the water continues to flow under the sand but if you remove it, you expose the water to dry out.

GS News: Do we know to what extent sand is being extracted through harmful methods?

PP: Despite the fact that it is the most used solid material on Earth, there is no global monitoring, so no one is actually looking at the figures. That's one recommendation that we give, it's very important that we start monitoring who's using what, from where, and for what purpose. At the moment, only some countries are doing it, and in other countries, we have no clue about how much sand is being taken.

The figures that we have are from a correlation between the use of sand and use of cement. Cement has been reported since 1990, because of the greenhouse gas emissions it produces and since you need sand, gravel and water to make concrete, we have a very good idea of how much sand and gravel has been used for construction. But we also use it for land reclamation and for industrial purposes.

GS News: One of your recommendations is for countries to develop a global framework. Do we need a treaty to regulate sand like the one being discussed for plastics?

PP: Countries already agreed in 2019 on a first resolution on mineral resource governance targeting sand and saying that we need to further study and look at best practices and all these things. They confirmed that decision in the UN Environment Assembly in 2022, again agreeing on a mandate to look at sand. So there is definitely awareness among countries, but we need to go further. I think we need to consolidate for example a centre that gathers the information from monitoring, collects statistics and best practices, and tries to issue guidance on standards and so on. At the moment, we do have best practices here and there, but some countries would highly benefit from the knowledge of other countries.

GS News: Like an IPCC but for sand?

PP: It might not necessarily need to be that big as the sand business is less complex than the climate system, and we may not need as many scientists. I used to be an IPPC author, so I have a good understanding of that process. [It could be] a centre where you can find the science, as well as policy and advice on best practices, a kind of library of all the knowledge that we have on this issue.

GS News: Sand is central to climate adaptation, acting as a barrier that protects coastal areas from rising sea levels or preventing floods in river basins. Could it be brought up at Cop27?

PP: Absolutely. Sand is very important for protection against sea level rise as it protects the shoreline from erosion. It also protects us against infiltration of salty water into coastal aquifers. Taking sand away from the beach would make us more vulnerable to climate change. The other way sand is associated indirectly with climate change is through cement, which is nearly one tonne of CO2 per tonne of cement produced. By using more concrete, we are exacerbating climate change, so if we find a solution to reduce the use of concrete, that would also mitigate the emissions that are causing climate change.

GS News: Sand is used to build bridges, roads, schools or homes, making it a key resource for developing countries. How do you balance out these two imperatives of development and protection of nature?

PP: Let's face it, we cannot do without sand and gravel. Concrete is very cheap, it's very easy to make any shape you want. It is easier than to use stone, for example. But until very recently, we were not building out of concrete. We were using earth bricks or adobe, especially in North Africa. Adobe has got a great advantage in terms of climate change. Walls made of adobe are much better for keeping the inside cool, whereas concrete radiates the heat and is not as good for thermal insulation. Some architects are now rediscovering these ancient materials, so you can build with wood, bamboo, straw, recycled materials and so on. We need to rediscover other types of material that may be less harmful for the environment, and that can be better recycled than concrete, which can be recycled a certain number of times and we should certainly also look at this possibility for a more circular use of these building materials.

GS News: If substitutes already exist, why are we not using more of them?

PP: We are talking about substituting about 50bn tonnes of sand and the only industry that is currently matching this kind of volume is the mining industry. Recently we've been looking at mine tailings [Editor’s note: the residues after the target mineral is extracted from the ore] from the iron industry. After they extract the iron, anything that is not iron, which is the vast majority, is dumped. But it isn’t toxic. When we analyse the chemistry of the material and the physical properties, it's very close to sand. It's a bit too fine for using it straight away, but by blending it with coarser material it can be used in concrete.

GS News: What can governments do to get the ball rolling?

PP: First of all, they have to recognise that sand is a strategic material and not just common material, and not only for infrastructure, but also for the environment. The second thing is to reassess the laws and policies so that we can use other alternative material, for example, this material from mining which some countries might authorise it, despite it being perfectly fit for purpose. You have to probably create incentives for people to recycle the material of demolitions because if you are not taxing the landfill, and it's cheap to get the material out from a river, then people will continue to do that.

Also, in many countries, especially in developing countries, sand extraction is an informal sector where people just need a shovel and a truck. They take it from the beach, from the rivers or from agricultural land, causing many problems. It's the responsibility of governments to really identify where the sand can be taken from.

GS News: The demand for silica sand, which is used for solar panels and renewable energy infrastructure, is also bound to increase. Can we really exploit it sustainably?

PP: We still have plenty of silica sand, so we should make sure that we are using it for that purpose. And there is definitely a huge demand for solar panels, so those resources should be really protected and managed wisely because we need them to switch to renewables as soon as possible. And with solar panels you don't need to build a power line, so it reduces the amount of infrastructure that is needed. But we have to be more clever on the way we're using these resources. Let's not think that those resources are infinite, they are slowly renewing at a geological time, so for a given life, it should be considered like a non-renewable resource.

GS News: Does this mean we also need to set limits on the use of sand and similar resources for the green transition?

PP: There is always a trade-off between development and the environment. We need to take it from where it causes the least impact on the environment and then if we do impact the environment we should restore it. That's another recommendation that we made in our report. When you set up wind turbines in the sea, initially you're destroying the ecosystem by placing those very large infrastructures. If you restore it afterwards and because people are not allowed to fish around the area, it becomes a huge biodiversity spot.