What if the world runs out of sand? | 91TV
Transcript
- VOICEOVER: In 2008, an entire beach in Jamaica vanished.
- 500 truckloads of glittering white sand
- was stolen under the cover of darkness and never found.
- In fact, sand is being stolen all over the world,
- highlighting how this seemingly plentiful material
- is now so valuable
- that people will go to extraordinary lengths to obtain it.
- Sand isn't just the gritty granules that trap between your toes
- when you're at the beach,
- it's a mirror of the Earth's history that takes thousands,
- if not millions, of years to form.
- The colours of sand tell stories of landscapes long gone.
- On tropical beaches, sand gleams white,
- formed from the crushed skeletons of coral and marine life.
- Along volcanic shores,
- it turns black from basalt born of molten lava.
- Red sands carry the tale of ancient iron-rich rocks oxidised over time.
- And it's not just what sand's made of,
- it's also what can live in it.
- The Machair sand dunes in Scotland
- are home to hundreds of plants and animals
- and show just how vibrant and full of life sand can be.
- Like tree rings, the layers of a sand dune tell its history.
- In the Namib Desert,
- scientists use optical luminescence to reveal the sand's age,
- calculating the last time it saw sunlight.
- In Utah, petrified Jurassic dunes, formed 180 million years ago,
- are hardened into a magnificent alien landscape.
- Sand exhibits mysterious and unusual physics.
- In the Sahara, singing sand dunes produce a haunting hum
- heard for kilometres.
- This phenomenon occurs when a disturbance, like a small avalanche,
- sets the dune vibrating like a plucked cello string.
- 28 million years ago,
- a meteor struck the Libyan Desert sand,
- and out of the intense forces
- forged one of the rarest materials -
- Libyan Desert glass.
- So rare and prized, it sits in the centre of Tutankhamun's breastplate,
- carved as a golden scarab.
- Sand's versatility as a building material
- was understood by the Romans.
- They figured out how to make sand with lime and volcanic ash
- to create concrete,
- an invention that's literally stood the test of time.
- The Romans constructed vast networks of roads,
- aqueducts and structures
- whose remains have survived for two millennia.
- The Pantheon in Rome has the world's largest unreinforced concrete dome.
- 4,000 years ago, in ancient Mesopotamia,
- humans first crafted glass
- using a simple mixture of sand, lime and soda,
- heated, then rapidly cooled.
- Today, it's in the windows we peer through,
- the screens we touch,
- and the fibre optic cables that carry our thoughts
- close to the speed of light.
- Silicon chips - the brains behind everything
- from smartphones to space shuttles -
- are also made from precious quartz sand.
- We're literally surfing the internet on sand particles.
- It's hard to imagine our world running out of sand
- when we have deserts like the Sahara
- covering 8% of the planet
- and totalling over nine million square kilometres,
- but desert sand, with its smooth, rounded grains shaped by wind,
- is useless in construction.
- It's like trying to build with marbles.
- Instead, the world's insatiable need
- for concrete buildings, bridges and motorways
- demands sand from rivers and coastlines
- which has angular grains that lock together like a jigsaw puzzle.
- And this usable sand is running out.
- Mining sand from rivers and coastlines disrupts ecosystems
- and threatens species that depend on those sediments.
- Sand flows down rivers, protecting shorelines,
- builds deltas and helps prevent flooding.
- When too much is taken, a chain reaction is set off,
- leading to severe floods and erosion
- and making us more vulnerable to nature's forces,
- and scarcity leads to crime.
- In parts of the world, so-called sand mafias,
- illegal mining gangs, dredge for sand so intensely
- that it's causing river banks to collapse, destroying villages.
- Those who oppose them often face violent retaliation.
- Sand has become a commodity so valuable
- that people are willing to kill for it.
- Today, concrete is the most common building material on the planet.
- If it were a country,
- it would rank among the world's top carbon emitters.
- If we were to embrace more sustainable building practices
- based on local materials and conditions,
- sand could be preserved
- for essential purposes
- and protected from overextraction.
- Vulnerable rivers and dunes could also be protected
- using cattle or sheep to naturally manage vegetation,
- shift sand and boost biodiversity,
- or by planting natural barriers like mangroves,
- to shield coastlines.
- So the next time you're walking on a beach,
- take a moment to feel the sand under your feet.
- You're standing on one of humanity's most prized resources,
- the remains of ancient ecosystems,
- and perhaps even the stuff that powers your smartphone.
- These tiny grains of sand are our history, sure,
- but they're also our future.
From concrete to mobile phones, modern life has long relied on sand as a key resource. But despite huge deserts and many thousands of beaches around the world, usable sand is running out.
Made in partnership with @bbcideas
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