Sand consumption worldwide reaches crisis stage


B. McPherson

Sand mafia are stealing people's homes
Who would have thought that sand and gravel was in short supply around the globe? Aggregates are as common as dirt, right? Apparently not so and the UN Environmental Programme is sounding the alarm, saying that the extraction of aggregates at this pace is not sustainable. The extraction is also causing widespread environmental damage.

Our modern world relies on the use of sand and gravel in many ways. As much as 59 billion tonnes of the material is mined every year. Sand is the result of millions of years of erosion and wearing away of bedrock. Gravel is just part way in that process. The trade in sand and gravel is a multibillion dollar business, estimated to be in excess of $18 billion each year.

Sand mining is usually done as open pit. Sources for sand may be dunes, beaches, dredged from rivers and glacial deposits. The sand may contain valuable minerals that can be sifted out to use in the chemical industry.

 The US has a massive deposit of silica sand that is funneled into the oil and gas industry to use in fracking. By far the most common use for sand and gravel is in making concrete. Concrete is a mixture of cement, water, sand and gravel. For every tonne of cement used six to seven tonnes of sand and gravel are used. When you think of all the tall buildings being constructed around the world, the scale of consumption starts to become clear.

Qatar, China and India are currently the biggest consumers of sand and gravel. You might well ask why Qatar doesn’t use desert sand in their construction as they have a large supply of it. The wind rounds the grains and makes it unsuitable for binding.

There are environmental and economic consequences when the mining of sand and gravel is not done responsibly. Beach erosion may drive away tourists but the removal of protective dunes may lay homes and property open to storm damage. The living organisms that would live in the sand are destroyed.

Consequences of sand extraction                                   
·         Biodiversity loss
·         Land losses due to material being carted away
·         Water changes, increase in turbidity, water table changes
·         Climate changes mainly due to cement production which produces much CO2
·         Loss of protection from extreme events like storm surges
                                                               

Sources:
Wikipedia       
United Nations Environmental Programme     

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