We complain a lot about concrete; about the horrible carbon footprint of cement and the environmental problems of mining gravel. Now Vince Beiser of The Guardian writes about “the global environmental crisis you’ve probably never heard of” – mining sand.
People often use the words cement and concrete interchangeably, but in fact cement is only one ingredient in concrete; a full quarter of it is sand. There is a lot of sand in the world, deserts full of it, but it is heavy and expensive to ship, so it tends to be mined close to where it is needed. And they need a lot of it.
The demand is voracious. The global urbanisation boom is devouring colossal amounts of sand – the key ingredient of concrete and asphalt. Shanghai, China’s financial centre, has exploded in the last 20 years. The city has added 7 million new residents since 2000, raising its population to more than 23 million. In the last decade, Shanghai has built more high-rises than there are in all of New York City, as well as countless miles of roads and other infrastructure.
It’s not just China, either.
Sand mining is causing environmental damage worldwide. In some places locals dig out riverbanks with shovels and haul it away with pickup trucks or donkeys; in others multinational companies dredge it up with machinery. Everywhere, the process impacts its surroundings in ways that range from cosmetic to catastrophic.
Monterey, California. Lough Neagh, Ireland. Taiwan. Portugal. Kenya. It’s all over the world. It is killing salmon in Washington State.
In Australia, flood plains that are home to the world’s biggest collection of rare carnivorous plants are being wiped out by sand mining. In Wisconsin and Minnesota, farmers fear that a recent boom in sand mining is polluting their water and air. In Vietnam, miners have torn up hundreds of acres of forest and farmers’ fields to get at underground sand deposits.
Sand is not a renewable resource. You might think there is lots of it, but that desert sand has been wind-blown and eroded and evidently smoothed out so that it doesn’t make good concrete, so we keep excavating it from places where it might continue to serve useful purposes, like ecosystems, shoreline protection and recreation.
It’s yet another reason that we should stop using concrete when there are other, renewable options like wood. Read more in the Guardian.