We are the planet's greatest diggers and miners. For tens of thousands of years humans have chipped away beneath the soils of this vast rocky planet, plundering its hard surface for tools, building materials and sparkling jewels. The question is what’s driven our hunger to churn up more and more of our planet's rocks and sediments and spread it around the surface, and does it matter?
We’re not the only species to recognise the value in strong, inert materials – chimps use stone tools and Neanderthals mined flint in Europe – but we’re the only creatures to have delved further to reach the metals and other minerals within. Whole civilizations have been based on this – some metals became so important that they defined cultural periods, the Iron Age and the Bronze Age, for example. Empires extended across the seas in search of precious metals, gems and fuels. The Romans invaded Britain for its metals, using hydraulic mining to harvest gold from deep within the rocks. Spain’s wealth 400 years ago is largely attributable to silver scraped from the hills of Potosi in Bolivia.
Some of this unearthed treasure, such as iron, was created billions of years ago inside a star; others, such as coal, were more recently formed from living forests that were buried in bogs and compressed by sediments some 300 million years ago. Some of these mined materials, like iron, are common in the Earth’s crust, some are rare, but none of these are replaceable or renewable within a thousands-of-years timeframe.
The industrial revolution, which made Britain the powerhouse of the world, catalysed a sharp increase in the volume of mining. Steam power, fuelled by coal, rapidly increased our capacity to delve for materials (including coal), as well as transporting and processing it. In 1700, more than 80% of the world’s coal was mined in Britain. Over the 18th and 19th centuries, as technologies improved, speculators explored new territory across Africa, Australia and the United States, looking for gold and other high-value metals and gems.
But it is over the past 60 years that we’ve witnessed a truly global revolution in the scale of our mining and extractions. We now move more than three times as much sediment and rocky materials than all the world’s rivers, glaciers, wind and rain combined, according to sedimentary geologist James Syvitski of Instaar, University of Colorado, Boulder.
“Every year, rivers move about 13 gigatonnes (billion tonnes) of sediment. To put that in perspective, 1 GT [gigatonne] is equivalent to 2 Great Walls of China,” Syvitski says. “We already mine around 9 GT of coal each year – by 2030, it will be 13 GT of coal. And we produce 13 GT of aggregate, 2 GT of iron ore each year….”
We are sculpting the Earth’s surface and taking material away at rates not seen before in geological time, says Syvitski. “There are millions of holes and burrows through the rock – kilometres long – from our drilling expeditions,” he says. We’ve left 568,000 mines abandoned in the US alone, and many millions more throughout the world.
We are even plundering some of the most inhospitable places on the planet, such as the freezing Arctic Ocean, the burning Atacama Desert and the deepest Atlantic, to reach oil and gas, diamonds and copper, uranium and rare metals that were unknown decades earlier but are now an indispensable part of the conveniences of modern life.
New “finds” promise untold wealth to the territories they lie beneath – and to the speculating companies that dig and drill – so nations from Uganda to Brazil are eagerly pursuing all explorations. The world has already seen some of the poorest nations dramatically rise to prosperity after substantial finds. Saudi Arabia, for example, is now one of the wealthiest nations after vast oil and gas wells were drilled, and Botswana has rapidly risen from poverty to a functioning, economically healthy democracy after diamonds were discovered.
However, such wealth has not come without its problems. Mining is a dirty, dangerous business. The world watched in horror as dozens of miners were trapped for months below ground in Chile in 2010. They were rescued, but a few months later workers in a New Zealand mine were less fortunate. These incidents occurred in some of the world’s best-run mines operated by the biggest companies: every year, thousands of small-time miners, many operating in illegal shafts under terrible conditions, perish without publicity. In China alone, around 50 miners die each week.
Mines are often plunged into land owned by poor local people with few rights, who have received little or no profit or compensation for their polluted fields, air, waterways or wildlands. Nigeria’s Niger Delta is a ruined slick of oil spills and leaks, which continues to poison the health of some of the world’s poorest people, infiltrates their drinking water and farmland, and kills fish. The ongoing environmental catastrophe there shows no signs of abating while one of the world’s richest oil companies pollutes with near-impunity and the poor continue to illegally tap the pipes, spilling and spreading the noxious liquid. Across the globe, from the Amazon to the Gulf of Mexico, oil formed from the burial, millions of years ago, of algae and plankton has been spilt and spread around the terrestrial surface with ecologically devastating consequences.
Coal and oil are not the only buried pollutants we’re bringing to the surface. Mining involves huge amounts of energy – obtained from burning fossil fuels – and water, often in places where both are scarce, which increases environmental pressure, as well as producing greenhouse gases that are warming the planet. And the methods used to separate out desired metals from the rest of the rock are often poisonous – whole river systems have been contaminated with mercury from gold panning, for example.
In our haste to reach the buried materials, we have resculpted the landscape, carving the tops from mountains, boring and shattering the ground with fracking, creating new mountains of slag and rock, even making artificial islands where none have existed before. The palm-shaped island off the coast of Dubai was formed from some 400 million tonnes of geological material, says Simon Price of the British Geological Survey, who studied it. "All the materials we use to build our modern world – our cities of glass and concrete and steel – are made from geological ingredients that are mined and put together in unnatural combinations," Price says.
Our hunger to reshape the planet with Earth-moving machinery is inching us closer and closer to a troubling end-point: we are depleting some resources to the extent that they are in danger of running out, or at least becoming economically unviable to extract, and our mining is moving into ever-more environmentally fragile areas.
In the next column, I'll be asking whether it's time to slow our planetary plundering, and I'll be looking at what happened in the last 60 years to produce such an escalation in our lust for Earthly materials.
On Wednesday 21 November, you can hear my conversation with Simon Price and others, as we discuss the changes humans are making to the planet in the Anthropocene, on Frontiers, BBC Radio 4 at 2100 GMT.