The most abundant scarce resource
On a planet with deserts like the Sahara, sand might be the last resource you'd expect to be scarce. Yet, we are running out fast.
A society without sand would look nothing like ours does. Imagine wherever you are right now without the buildings, roads, glass—from your windows to your phone screen—and microchips. Though neither the wooden table nor metal chair legs consist of sand, they owe their existence to a world dependent on sand for their production.
Humanity consumes 50 billion tonnes of sand every year, averaging 18 kilogrammes per person per day.
Couldn't deserts provide us with sand forever?
We more or less have an infinite supply of sand at our disposal. But there are two problems.
Sand consists of crushed rock—it is super heavy. If you're planning to, say, build a megacity in China, you don't want to ship it halfway across the map from the Sahara. Ideally, you'd extract the sand where you need it.
But even if you could get your sand delivered from any desert, it wouldn't make a difference. Millennia of wind and erosion have ground desert sand to beautifully fine and smooth grains. It is no good as a construction material. Building a sand castle using desert sand is like building a house with marbles.
Wrecking the sand factory
To get a grip, you'll need sand that is a bit more jagged around the edges. This you will find where the sand is formed: at the bottom of rivers or beaches.
And here, the illusion of infinite sand breaks down.
Rivers form biodiversity highways between natural areas and are vital ecosystems themselves. Entering these ecosystems with the biggest excavators in the history of humankind has devastating impacts on the riverbed itself, and wherever the river flows after. Unsustainable sand mining destroys natural environments and their ability to generate new sand at a rate that is difficult to imagine.
It takes time—ages—for a river to grind its bedrock into fine particles. We are extracting sand faster than it can be replenished. And so we are digging ourselves into a hole that is hard to get out of.