I'd never thought of sand as being a scarce resource, but according to an article in Der Spiegel, to an ever-increasing extent it is.
Never before has Earth been graced with the prosperity we are seeing today, with countries like China, India and Brazil booming. But that also means that demand for sand has never been so great. It is used in the production of computer chips, plates and mobile phones. More than anything, though, it is used to make cement. You can find it in the skyscrapers in Shanghai, the artificial islands of Dubai and in Germany's autobahns.
. . .
In 2012, Germany alone mined 235 million tons of sand and gravel, with 95 percent of it going to the construction industry. The United Nations Environment Program (UNEP) estimates global consumption at an average of 40 billion tons per year, with close to 30 billion tons of that used in concrete. That would be enough to build a 27-meter by 27-meter (88.5 feet) wall circling the globe. Sands are "now being extracted at a rate far greater than their renewal," a March 2014 UNEP report found. "Sand is rarer than one thinks," it reads.
At times, the paucity of sand has even forced workers to put down their tools at construction sites in India and China. It has also halted fracking-related drilling in the United States because the process requires that sand be mixed in with the water pumped into the ground in order to keep open the fissures from which gas is extracted.
"Sand is like oil," explains Klaus Schwarzer, a geoscientist at Germany's University of Kiel. "It is finite." Western Carolina University's Young adds, "If we're not careful, we'll run out of sand."
In 2012, the environmental organization Global Witness released satellite images showing how Singapore has expanded its territory by 22 percent over the past 50 years. The group provided evidence that the sand used to enlarge Singapore came from neighboring countries like Vietnam, Indonesia and Malaysia and had, in some instances, been extracted illegally. One country after the other then issued a ban on mining sand. Singaporean dredging vessels responded by setting course for Cambodia. Phnom Penh responded by likewise banning exports of the resource.
. . .
Sand is similar to fossil fuels like natural gas, coal or oil: It takes thousands of years to form -- for rock to be naturally ground down into sand with rivers washing, grinding and breaking up stone on their long journeys to the sea. But the global population is growing, and since the start of the economic booms in Asia and Africa, sand doesn't even make it to the oceans anymore in some places. It often gets fished out before getting there.
. . .
One might think that the Arab Peninsula, with its high sand dunes, would have the largest reserves, but desert sand isn't suitable for every purpose. It contains a surfeit of chalk, clay and iron oxide. And while the countries have considerable amounts of marl, quality sand is also necessary to produce cement. Paradoxically, then, the desert region is suffering a shortage of sand.
There's more at the link, including a photo gallery showing the expanding use of sand.
The article's well worth reading in full. It shows how sand is used far more widely than most of us know. For example, I had no idea that 'fracking' requires sand as well as water, or that countries were dredging sand from off the coasts of other countries - sometimes without bothering to ask.