I read an interesting story by Laura Cole in the latest issue of Geographical, the magazine of the Royal Geographical Society in London. The story focused on sand mining.
Maybe you are better informed than me, but I had no idea that sand is “the single most mined commodity, eclipsing minerals and metals by a colossal margin”. I always assumed that sand is one of those items that will always be there, and I had not given much thought to the fact that one day we may run out of sand.
Sand was a regular feature of my youth in the south of the Netherlands. We lived far from the coastal sand dunes, but we had an inland sand dune landscape – the Loonse and Drunese Duinen. It was a popular spot for walking our dog, looking for chanterelle mushrooms in the autumn and generally having a hike during the weekend. In those days it was quiet, and we would walk for hours without seeing many other people. I recall rabbits, the occasional roe deer and sometimes a fox early in the morning. In 2002 the area was declared a National Park, and it is now a popular destination for local recreation.
I never thought much about sand until the seventies, when I lived and worked in Botswana as a land-use planning officer. The country is a semi-desert, and the river beds are dry for most of the year. They are filled with sand (a problem when you want to get across by car) and the sand was often dug for local use. But, this was small-scale local extraction, and while there was a concern about water availability, we never talked about the risk of the sand being a finite resource. So I was very surprised to read the Geographical story that warns about the serious implications of mining of sand.
After reading the story, I started looking for other information on the web, and there are some astounding news reports:
- Global production of concrete has risen by a quarter in just five years, fueled by the insatiable demands of China and India for housing and infrastructure;
- China used more concrete between 2011 and 2013 than America did in the entire 20th century;
- Concrete is a mixture of cement, sand and gravel, and globally our annual aggregate (N.B. this is sand and gravel) consumption is somewhere around 53 billion. This is expected to increase to 60 billion tonnes per year by 2030;
- Singapore is currently the world’s largest importer of sand, owing to its land reclamation activities which have seen the city-state’s land area increase by 20% in 40 years;
- Wind action in deserts results in rounded grains that are too smooth and too small to bind well in concrete, so you cannot use most of the sand from the deserts for concrete manufacturing.
Yet, despite these news stories, there is not a lot of scientific information available about sand mining, although this is obviously a growing environmental disaster. In fact, a 2019 report from UNEP – “Sand and Sustainability: Finding new solutions for environmental governance of global sand resources” – says that the scale of the challenge inherent in sand and gravel extraction makes it one of the major sustainability challenges of the 21st century. The UNEP report was the result of an expert round table event in October 2018, which seems to be the first time that scientists talked about sand extraction and consumption.
The report admits that there are real gaps in statistics about global sand extraction, and some of their figures are extrapolation from cement statistics which are apparently quite reliable. The report claims that typically 1 ton of cement is used to produce 10 tons of concrete. 2.5 tons of the concrete mix is sand, and another 4,5 tons is gravel. Given that annual cement production is reported to be some 4.1 billion tonnes in 2017, 40 billion tons of concrete was produced in 2017, which used more than 10 billion tonnes of sand.
One website that provides a running commentary about sand extraction is the blog by Kiran Pereira, called: http://www.sandstories.org/about/. She says that “Sand Stories works to create awareness about the urgent need to manage our consumption of sand as a resource. We aim to bridge the gap between science, policy and industry by identifying and promoting potential solutions to the looming sand crisis.” Most of her news is about India, where sand mining is apparently a real issue, and there are many local news reports about sand mining in India.
I read that in 2016 national sustainable sand mining guidelines were issued to control the Indian sand extraction industry, but these guidelines were often ignored. In a more recent study, the Government of India admits that “…in spite of the above-suggested guidelines being in existence, on the ground level, illegal [sand] mining is still going on”. Therefore, new, improved Monitoring and Enforcement guidelines were enacted earlier this year, and the authorities hope this will stem some of the rampant extraction.
But, I also learned that mining sand is not just an issue of the global South. Europe is using a lot of sand for its construction industry as well, and much of that is dredged from the North Sea and surrounding mudflats. I found information from the Belgian Government that the yearly extraction volume of Belgian sea sand is currently about 3 to 4 Million m³, almost 75 % of which is used in the construction sector. A similar report from the UK Crown Estate states that 403 million tonnes of marine sand and gravel was dredged from UK-licenced areas between 1998 and 2017. In the text, this is converted to 245 Million m³, and I therefore reckon that the UK dredges an annual volume of some 12 Million m³.
Another major use of sand in northern Europe is so-called beach nourishment, which is a term to describe the artificially depositing of sand offshore or on beaches that have lost sand due to erosion, changing currents and other environmental processes. One of the serious long-term challenges for northern Europe is that one the one hand the continental shelf is slowly subsiding, while on the other hand the melting ice on the north pole is raising sea levels. This means that low-lying areas along the coast of the countries bordering the North Sea are under threat, and one way to help them is to reinforce the beaches and the dunes behind them.
A 2010 article from Hydro-International claims that the amount of sand needed for nourishment along the Dutch coastline is likely to increase from an annual amount of 12 Million m³ to about 80-100 Million m³. That seems to be a lot, compared to the UK report that I quoted above, but the Dutch North Sea Policy 2016-2021 states that the Netherlands currently already extracts in excess of 25 Million m³ per annum, half of which is replenishment sand for coastal reinforcement and half of which is sand for construction and other uses.
How do we deal with this demand for a finite natural resource? In a 2019 reflection on this issue, Oli Brown claims the three main issues are: 1) to reduce demand for sand; 2) finding alternatives wherever feasible, and 3) ensuring that primary sand is extracted in the most responsible and sustainable way possible. Finding alternatives would include recycling sand, and the Geographical report claims that there are ways. Apparently, Japan has created a method for fine sand production by crushing quarry waste, and there are industry initiatives to recycle concrete. But, sand is so cheap that recycling building waste is not yet worth-while from an economic viewpoint.
It was very interesting to find out a little about this growing environmental issue, and with the continued growth of cities, it is something that may well become even more serious during the course of the next decades.
These are some of the news stories about sand that I read recently: