Geology and Civilization Part 4: Slipping Through Your Fingers

Part 1, Part 2, Part 3

It may have come to your attention that the past couple of articles in this series have been discussing our use of natural resources. This is quite deliberate, and the early parts of this series will continue in that vein for some time. Today we're going to talk about another nonrenewable resource that we're burning through at an unsustainable rate. In fact, it's the single most used resource other than water, air, or dirt. We're rushing through our supply faster and faster every year. It's getting so scarce in some regions that organized criminal groups have begun to form around it, with violent deaths occurring more and more frequently over it. What's the resource? Sand.

[Image source]

It seems bizarre to claim that we're running out of sand- perhaps even moreso than claiming we're running out of dirt. After all, isn't the Sahara covered in thousands of square miles of sand, often to a depth of hundreds of feet? Well, unfortunately, all that desert sand is straight out of the picture. As desert sand is shaped and weathered by wind instead of water, the grains tend to be too round to work for our purposes. The more irregular shapes of marine sand are needed instead. What is our main purpose for sand? Construction. Specifically, for concrete- concrete is essentially sand and gravel glued together by cement. Cement isn't structurally sound enough on its own to make a building out of.

Of course, concrete isn't the exclusive use for sand. Sand is used as an ingredient in glass, solar panels, computer chips mortar, paint, and bricks. It's used in casting, making icy road drivable, and more processes. Still, making concrete with it for construction purposes is still the heaviest use we have for sand. In fact, we go through 40 billion tons of sand and gravel each year. Sand extraction is a $70 billion dollar industry annually. Unfortunately, we're going through it at a far, far faster rate than sand is being produced- it's a relatively slow geological process that can take millennia or longer in some regions.

A closeup on sand. [Image source]

Dubai, jewel of the United Arab Emirates, is going through an absurd growth rate. In a few short decades, Dubai has gone from being a minor port city to one of the most prosperous cities on the planet. Over 97 percent of its inhabitants are immigrants. Emiratis are as rare in the city as Native Americans in America. The absurd pace of construction has entirely drained nearby sources of sand usable for construction. It's lead to the truly absurd situation of Dubai having to import sand from Australia, despite being built in the desert. Selling sand to Arabs seems like it should be a saying talking about something that's impossible.

If Dubai's demand for sand is huge, China and India put them to shame. Each are constructing massive megacities left and right, projects that demand immense quantities of sand. India is the global hub of illegal sand mining, with a huge percent of the world's sand mining related murders found there. Over 35 million people are employed by India's construction industry, and without sand, it'll all grind to a stop. The sheer amount of money involved means that powerful officials and politicians are frequently bribed to ignore the problem. The demand is so huge that poor fishermen actually dive 40-50 feet to the bottom of the Thane River to collect sand in buckets, as much as 200 times per day.

Sand being sorted by size at a gravel pit. [Image source]

Methods of sand mining are certainly diverse. In places, men haul it up with shovels and pickup trucks. In other areas, it's dredged out of the ground with massive mining machines. Huge ships dredge river bottoms for sand. Many areas are rapidly running out of such sand, so there are now fleets of thousands of ships vacuuming up sand from the seafloor. Sand mining is even a growth field in the United States- a new sand mine near Lubbock, Texas was just announced two days ago. It'll employ 85 or more new workers and will output 2.6 million tons of sand per year.

All of these methods of mining have serious environmental consequences. The riverine and oceanic sand mining is especially destructive- it creates huge sediment plumes that choke aquatic life and can potentially contribute to deadly algal blooms. Fish and seabirds tend to be especially badly harmed this way. Entire rivers have been lost to sand mining as well. Many rivers have deep, sandy beds that act as aquifers for water, helping regulate water flow. When the beds are removed, water tables drop precipitously and the river dries up. The Manimala River in India, once a respectable 92 kilometer waterway, has now largely dried up thanks to sand mining. Depressingly, it was the very villagers along the river who mined the sand. They sacrificed their very way of life and their land to short term profits, and now the water table is so low they have to ship water in by truck.

The Manimala River, once a mighty torrent as seen here, is now a mere trickle along much of its length. This section only retains any depth due to it being monsoon season and being close to a dam. [Image source]

The land mining can be destructive too- often ground cover is ripped off of sandy substrates so it can be mined, which then results in much of it becoming windblown, creating sandstorms in places unused to them. Sand mining has been known to result in increased reasonable susceptibility to landslides and flooding by stripping beaches, hillsides, riverbanks, and floodplains. Local infrastructure can also be badly damaged. In India, quite a few bridges have been seriously undermined by sand mining in the river reducing their support.

Over two dozen Indonesian islands have been entirely wiped off the face of the map since 2005 by sand mining. Most of their sand has gone to Singapore, the single biggest importer of sand. They require immense amounts in order to keep growing their island farther into the sea, and their demand is so rapacious that it's led to China, Indonesia, Malaysia, and Vietnam all banning exports of sand. It's still mined and sold to Singapore and other locations illegally, however.

*Sand mining in progress. Note the terrible condition of the river and the * [Image source]

Sand mining has been a lucrative source of income for criminal gangs around the world. Literally hundreds of murders have been attributed to sand mafias in India, with as many more elsewhere around the world. Sand related bribes and sexual favors are one of the leading sources of corruption for government officials in a dozen nations. Banning the mining of illegal sand has done little, and enforcement buckets are futile attempts to dam a leaking dike with a finger. (The US has largely banned coastal sand mining, but the US has the most powerful law enforcement abilities of any nation, so it's a bit of a different case.) Sand mining requires incredibly little starting capital, and is done in large part by hordes of faceless independent small miners. Arrest one and a dozen more will take their place. As long as demand remains so high, illegal and environmentally destructive sand mining will continue.

So what are our potential solutions? It is possible to construct sand by smashing rocks, but it's not the best quality sand- and it's often only affordable due to borderline slave labor. Mechanically smashing it would be expensive and contribute huge amounts of carbon to the atmosphere. We've been experimenting with shredding plastic, wood, and other alternatives to sand as a concrete ingredient, but none of them have caught on so far, and are still quite expensive.

Singapore's Marina Bay, built on reclaimed land constructed out of huge amounts of sand dumped into the ocean. The island city-state used up literally all its sand in this and other land reclamation processes, leading to it becoming the world's leading sand importer. Singapore has increased its total size by over 23% through these projects already, and is anticipated to expand by nearly as much again by 2030. [Image source]

Our only real solutions? Reduce our dependence on concrete construction. When we do need sand, be careful to mine it only from rivers that are suffering oversilting problems- often from our own actions, so that mining them could actually be fixing problems we solve. Use more renewable materials like wood & bamboo. Begin recycling old concrete. Like so many environmental problems caused by our technology, the solution cannot be a technological one. That's just slapping a band-aid on the problem. We need to address the fundamental behaviors causing us to damage our ecosystems rather than trying to fix them after the fact.

Bibliography:

-A History of Future Cities, by Daniel Brook