Friday, July 29, 2016

Our Shrinking Sand Box

Just when you think the world has enough to worry about . . . .

Now it seems our planet is running out of sand. Yes, sand. Who would have thought it? I mean there are millions of square kilometres of sand in places like the Sahara, The Kalahari, the Arabian, and many other deserts. 

However, a United Nations environmental report says that sand and gravel are being mined faster than earth can replace them. Sand is made by wind and water erosion, a process that takes thousands of years.

It has been estimated that we humans are using 40 billion tonnes of sand and gravel every year to construct buildings, bridges, roads and other stuff. That is twice the amount of sediment produced each year by all the rivers in the world.

Sand and gravel, of course, are bound with cement to make concrete. The 40 billion tonnes of aggregates we use every year is enough to build a concrete wall 27 metres high and 27 metres wide around the equator. (It wouldn’t take nearly that much to build Donald Trump’s wall between Mexico and the United States.)

China has become the world’s biggest user of concrete. Between 2011 and 2013 China is estimated to have used more concrete than the United States did in the entire 20th century. In just one year it built 146,400 kilometres of road.

Sand also is used in the production of glass, electronics and aeronautics. Land reclamation is another use that consumes huge amounts of sand and general fill.

Most of our aggregates are pulled from obscure gravel pits found off the beaten track. We pay scant attention to them.

However, sand mining is a serious environmental problem in some parts of the world where everything from monster river dredges to labourers with shovels are used to extract sand for building. In some places sand is even being taken from beneath the seas.

The environmental costs of this mining are mounting and environmental organizations are fighting for practices and laws to control it.

They blame erosion of San Francisco beaches on sand mining. And, they say sand extraction from India’s rivers is harming ecosystems, killing fish and birds. Also that hundreds of acres of forest in Vietnam have been torn up to extract sandy soil. Bridges have been undermined in some places and coral reefs have been damaged in Kenya.

In Cambodia, the big dredges moved into the Ko Kong area almost 10 years ago to pluck huge amounts of sand from the coastline. Critics say the sand is being taken illegally to support the rampant expansion of Singapore. They say mangrove and estuary ecosystems are being ruined, killing the livelihoods of local people, including those who fish for a living.

Sand is worth money and money attracts corruption faster than bear poop attracts flies. A recent New York Times opinion article estimated that sand extraction is a $70 billion industry and that’s plenty enough to attract criminal syndicates.

The UN report says that half the sand used in Morocco comes from illegal coastal sand mining. Sand is removed from beaches to build hotels, roads and other infrastructure needed for the tourism industry. Which leaves the question: when the beaches are gone, what happens to the tourist industry?

With so much sand in the world’s deserts why don’t sand mining companies pick up their pails and shovels and go there? Well, apparently desert sand is not suitable for concrete production or land reclamation because most of it is round, wind-shaped grains that do not bind well.

Environmental groups demand stiffer regulations to control sand mining. But more controls could bring other problems.

Sand is heavy and costly to transport. Trucking greater distances creates more pollution, more traffic problems and all the fallout that comes from that. So you want to get sand and gravel as close as possible to the place that you are using it. Unfortunately, the closest place often is a beach, or an environmentally delicate estuary.

The world is a complicated place, and becoming more complicated every day. Who would have thought we would ever have to worry about running out of sand?


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