SOURCE: The Guardian
DATE: July 1, 2018
SNIP: Our insatiable appetite for new buildings, roads, coastal defences, glass, fracking, even electronics, threatens the places we are designed by evolution to love most. The world consumes between 30 and 40bn tonnes of building aggregate a year, and half of this is sand. Enough material to build a wall 27m high and 27m wide around the equator. Sand is second only to water as a natural material extracted by humans, and our society is built on it, quite literally. Global production has risen by a quarter in just five years, fuelled by the insatiable demands of China and India for housing and infrastructure. Of the 15 to 20bn tonnes used annually, about half goes into concrete. Our need for concrete is such that we make almost 2 cubic metres worth each year for every man, woman and child on the planet.
But what of those oceans of sand stretching from the Atlantic to the Persian Gulf – the Sahara and the Arabian Desert? The wrong kind of sand, unfortunately. Wind action in deserts results in rounded grains that are too smooth and too small to bind well in concrete. Builders like angular sand of the kind found on riverbeds. Sand, sand everywhere, nor any grain to use, to paraphrase Coleridge.
Riverbed sand is prized, being of the correct gritty texture and purity, washed clean by running fresh water. Marine sand from the seabed is also used in increasing quantities, but it must be cleansed of salt to avoid metal corrosion in buildings. It all comes at a cost.
International trade in sand is rising as local supply outstrips demand. The destruction of habitats vital to fish, crocodiles, turtles and other forms of riverine and marine life accompanies the destruction of sand barriers and coral reefs protecting coastal communities.
No one knows how much damage is being done to the environment because sand extraction is a largely hidden threat, under-researched and often happening in isolated places. Sand dredging degrades corals, seaweeds and seagrass meadows and is a driver of biodiversity loss, threatening species already on the verge of extinction. Our consumption of sand is outstripping our understanding of its environmental and social effects.
Sand accounted for 85% of the total weight of mined material in 2014, yet it is replenished by rock erosion only over thousands of years. Booming demand means scarcity, scarcity means money and money means criminality. Why buy expensive sand, sourced from licensed mines, when you can anchor your dredger in some remote estuary, blast the sand out of the riverbed with a water jet and suck it up? Or steal a beach? Or dismantle an entire island? Or whole groups of islands? This is what the “sand mafias” do. Criminal enterprises, their illegal mining operations in Asia, Africa and elsewhere, are protected by officials and police paid to look the other way – and powerful customers in the construction industry who prefer not to ask too many questions.
Our demand for sand appears ever more insatiable. Can rampant sand extraction be curbed? A win-win solution is the use of waste plastic in making concrete. Research suggests small particles of plastic waste – “plastic sand” – can replace 10% of the natural sand in concrete, saving at least 800m tonnes per year.*
*My note: Except that using plastic in concrete means we doom the world to plastic pollution that will continue long after we are gone as the plastic-containing concrete we create crumbles away….
I recommend reading the whole article. It is eye-opening.