Paradise is a beach, we are told. Pristine white or coral pink. We leaf through brochures in search of perfect sand. There is a Paradise Beach on Barbados, and in Croatia, and Thailand, and South Africa, too. In every tourist-hungry part of the globe, in fact. The naturalist Desmond Morris believes that, as descendants of water-loving apes, we are hard-wired to seek out these places, lulled by the rhythmic advance and retreat of the ocean as we soak up the sun, sand grains trickling through our workless fingers.

And so much to go around. Man has always used sand as an analogy for the infinite, a limitless resource, ordinary and yet magical, incapable of exhaustion. When astronomers seek to impress upon us the size of the universe, they speak of stars being more numerous than grains of sand. There are quite a few grains, as it happens – 7.5 x 10 to the 18th power, according to researchers at the University of Hawaii. That’s 7 quintillion, 500 quadrillion – give or take the odd trillion.

Yet sand in the right places is anything but infinite. Our insatiable appetite for new buildings, roads, coastal defences, glass, fracking, even electronics, threatens the places we are designed by evolution to love most. The world consumes between 30 and 40bn tonnes of building aggregate a year, and half of this is sand. Enough material to build a wall 27m high and 27m wide around the equator. Sand is second only to water as a natural material extracted by humans, and our society is built on it, quite literally. Global production has risen by a quarter in just five years, fuelled by the insatiable demands of China and India for housing and infrastructure. Of the 15 to 20bn tonnes used annually, about half goes into concrete. Our need for concrete is such that we make almost 2 cubic metres worth each year for every man, woman and child on the planet.

But what of those oceans of sand stretching from the Atlantic to the Persian Gulf – the Sahara and the Arabian Desert? The wrong kind of sand, unfortunately. Wind action in deserts results in rounded grains that are too smooth and too small to bind well in concrete. Builders like angular sand of the kind found on riverbeds. Sand, sand everywhere, nor any grain to use, to paraphrase Coleridge. A textbook example is the Burj Khalifa in Dubai, the world’s tallest skyscraper. Despite being surrounded by sand, it was constructed with concrete incorporating the “right kind of sand” from Australia. Riverbed sand is prized, being of the correct gritty texture and purity, washed clean by running fresh water. Marine sand from the seabed is also used in increasing quantities, but it must be cleansed of salt to avoid metal corrosion in buildings. It all comes at a cost.

The Burj Khalifa, Dubai: ‘Despite being surrounded by sand, it was constructed with concrete incorporating the “right kind of sand” from Australia.’ Photograph: Bloomberg via Getty Images

China leads the charge in today’s sand-fuelled construction boom, consuming half the world’s supply of concrete. Between 2011 and 2014 it used more concrete than the United States did in the entire 20th century. Aggregate is the main ingredient for roads, and China laid down 146,000km of new highway in a single year. By 2050, two-thirds of humanity will live in urban areas, a product of migration and population growth. The population of India, second only to China in its hunger for concrete, is expected to grow from 1.32bn to 1.7bn by the middle of the century. Mumbai, India’s commercial capital, is one of the world’s top 10 mega-cities, with a population of 22m. China and India rely largely on national supplies of sand – to minimise transport costs – but as the skyscrapers rise in Shanghai and Mumbai so does the price of this once-humble ingredient. China’s hunger for sand is insatiable, its biggest dredging site at Lake Poyang produces 989,000 tonnes per day.

International trade in sand is rising as local supply outstrips demand. The destruction of habitats vital to fish, crocodiles, turtles and other forms of riverine and marine life accompanies the destruction of sand barriers and coral reefs protecting coastal communities, as in Sri Lanka. Sand extraction lowers the water table and pollutes drinking water, as in the Mekong Delta of Vietnam, while stagnant pools created by extraction on land foster malaria.

No one knows how much damage is being done to the environment because sand extraction is a largely hidden threat, under-researched and often happening in isolated places. “We are addicted to sand but don’t know it because we don’t buy it as individuals,” says Aurora Torres, a Spanish ecologist who is studying the effects of global sand extraction at Germany’s Centre for Integrative Biodiversity Research. “Extraction has grown strongly over the past four decades and has accelerated since 2000. Urban development is putting more and more strain on limited accessible deposits, causing conflict around the world. Sand dredging degrades corals, seaweeds and seagrass meadows and is a driver of biodiversity loss, threatening species already on the verge of extinction. Our consumption of sand is outstripping our understanding of its environmental and social effects.”

Why buy expensive sand from a legal mine when you can suck up a riverbed? Or nick a beach? Or an entire island?

Sand accounted for 85% of the total weight of mined material in 2014, yet it is replenished by rock erosion only over thousands of years. Booming demand means scarcity, scarcity means money and money means criminality. Globally, sand extraction is estimated to be worth £50bn per year, a cubic metre of sand selling for as much as £62 in areas of high demand and scarce supply. This makes it vulnerable to illegal exploitation, particularly in the developing world. Why buy expensive sand, sourced from licensed mines, when you can anchor your dredger in some remote estuary, blast the sand out of the riverbed with a water jet and suck it up? Or steal a beach? Or dismantle an entire island? Or whole groups of islands? This is what the “sand mafias” do. Criminal enterprises, their illegal mining operations in Asia, Africa and elsewhere, are protected by officials and police paid to look the other way – and powerful customers in the construction industry who prefer not to ask too many questions.

From Jamaica to Morocco to India and Indonesia, sand mafias ruin habitats, remove whole beaches by truck in a single night and pollute farmlands and fishing grounds. Those who get in their way – environmentalists, journalists or honest policemen – face intimidation, injury and even death. “It’s very attractive for these sand mafias,” says Torres, who is one of the few academics studying this Cinderella issue – overshadowed as it is by climate change, plastic pollution and other environmental threats. “Sand has become very profitable in a short time, which makes for a healthy black market.”

Reporting on this illegal trade can get you killed in India. In March this year, Sandeep Sharma, a reporter with a local television station, was mown down by a sand truck after filming a police officer accepting a bribe in return for turning a blind eye to sand mining in a crocodile sanctuary. Last month, a special branch constable in Tamil Nadu also paid with his life for gathering intelligence at an illegal mining site. Mumbai environmentalist Sumaira Abdulali is India’s foremost campaigner against illegal sand mining, a distinction that led to an attempt on her life in 2010. “The problem extends even to tourist beaches in Goa, Kerala and elsewhere,” she says. “Most people are afraid to complain – even government officials and police officers are afraid to approach illegal sites. Murders, threats and acts of intimidation between them probably number in the hundreds.”

In southeast Asia, sand is a crucial ingredient in geopolitics. China’s imperial ambitions in the South China Sea are being furthered by the construction with sand of artificial islands hosting military bases intended to reinforce its claims in the region. This novel form of territorial expansion is also being pursued by rich but tiny Singapore, resulting in conflict with its bigger neighbours. The population of the city state has more than trebled to 6m since independence from Britain in 1963, resulting in a literal land grab. The world’s biggest importer of sand, Singapore has contrived a 20% increase in its land area using sand sourced from Indonesia, Malaysia, Cambodia and Thailand, much of it illegally. In 2008, it claimed to have imported only 3m tonnes of sand from Malaysia, but the real figure, according to the Malaysian government, was 133m tonnes, almost all of it smuggled, allegedly. As Singapore grows so its vast neighbour Indonesia shrinks. Illegal sand extraction threatens the very existence of some 80 small low-lying Indonesian islands bordering Singapore, playing havoc with marine ecology.

Singapore is the world’s biggest importer of sand, increasing its size by 20% using sand from Indonesia, Malaysia, Cambodia and Thailand. Photograph: aiqingwang/Getty Images

Given the vast forces at work, the incomes and even lives of small farmers and fishermen in sand-rich areas are considered expendable. Bhaskar Rao Patil has never known wealth but the waters he fishes once provided enough to meet the modest needs of his family. Now they are barren, ruined by sand dredging. Patil lives in Bankot, a small coastal fishing town some 200km south of Mumbai. Across the estuary of the Savitri River, his nemesis is hard at work: a sand dredger, sucking up the bed of the river before depositing its “catch” in barges which then discharge their cargo into dumper trucks destined for Mumbai. Sought-after fish caught at the rate of 50 an hour in good times now number just five a day. A fishing boat of the kind he uses once supported five families; now it is two.

“The only time we think about sand is on a beach holiday, but our lives are built on it,” says London-based Indian researcher Kiran Pereira, who has interviewed many people affected by rapacious sand mafias. Their accounts are published on her website, sandstories.org. “In some cases, people initially welcome sand mining because it creates jobs,” she says. “But once they see the effects it is too late to change.” The fishermen of western India must collude in the destruction of their fast-disappearing world. Around Mumbai, some 80,000 of them have changed their catch from fish to sand, so spoiled are their fishing grounds and so high is the demand for this basic material.

Sand extraction is a developed world problem, too. In the US, sand mining for fracking has despoiled areas of Wisconsin, provoking protests from local people. And in the UK, Friends of the Earth has been fighting a long battle to curb sand dredging on Lough Neagh in Northern Ireland, one of Europe’s most important wetlands. Some 1.7m tonnes of sand are sucked up each year by dredging companies, despite the lake, the largest in the British Isles, being a protected area under domestic and European law. Friends of the Earth claim the local bird population has declined by more than 75% in the past 30 years, and fish habitats have been harmed by worsening water quality. “Despite rich layers of protection, the government has for decades turned a blind eye to the scouring of the bed of our biggest nature reserve,” says James Orr, director of Friends of the Earth in Northern Ireland. “It is a Klondyke on Lough Neagh.”

The British love affair with the seaside encourages this unnatural practice

The demands of the construction industry are not the only problem, however. Around the world, the natural coastline is threatened by other forms of human interference. “Most natural sand beaches are disappearing, partly due to rising sea levels and increased storm action, but also to massive erosion caused by development of the shore,” says Andrew Cooper, professor of coastal studies at the University of Ulster and co-author of The Last Beach. The building of sea defences and so-called “beach nourishment” (dumping fresh sand on tourist beaches to combat erosion) store up trouble for the future, he says, disrupting the natural movement of waves and sand along the shore.

“Beach nourishment is not a panacea for coastal erosion,” says Cooper. “It is, like a seawall, a means of holding a naturally mobile coast in place. And, like a seawall, it requires ongoing maintenance. Beach nourishment causes damage in the source area, killing all that goes into the dredger, before smothering and killing most things on the beach where it is placed. The beach it creates may serve as a recreational platform, but many studies have shown that nourished beaches are very poor substitutes for the natural ecosystems they replace.”

Yet the British love affair with the seaside, sustained by memories of idyllic bucket-and-spade holidays in youth, encourages this unnatural practice. In 2006, Lyme Regis turned to France for sand to replace that washed away by the constant motion of the English Channel, the Dorsetshire resort’s burghers justifying the expense by claiming that Gallic sand grains were less easily washed away than Anglo-Saxon ones. More sand (English this time) was needed in Dorsetshire to rebuild beaches washed away by the vicious storms of January 2014. Bournemouth, meanwhile, has opted for cosmetic surgery to maintain its appeal, spending £3.6m to dump 320,000 cubic metres of supposedly “perfect” sand, sourced locally, on to its denuded beaches.

Of course, you can always steal sand to nourish your beach, rather than buy it. In 2008, at Coral Spring on the north coast of Jamaica, 500 truck-loads of pristine sand was spirited away in a single night, never to be seen again. And when sand was required last year for a new resort in the Canary Islands it was imported (illegally, say environmentalists) from Western Sahara, the former Spanish colony now occupied by Morocco. Sand looted from beaches and riverbeds in the disputed territory is shipped north to Morocco for construction and to nourish the kingdom’s tourist beaches. “Beach nourishment is like a sticking plaster,” says Cooper. “It does not remove the underlying reasons for erosion. Worse, it provides a false sense of security. In future, as sea levels rise, it will demand bigger and bigger volumes of sand to be effective.”

If the natural coastline, with its inconvenient shingle, its messy flotsam and jetsam, its sheer reality, does not suit, one can always visit a pop-up beach. These ersatz paradises spring up each year in major cities, created with sand imported by lorry. In London, a fiver will buy you access to “Fulham Beach” this summer, and “Hampstead Beach” is free. Brent Cross shopping centre may not be a contender for Condé Nast Traveller’s top 10 beach settings, but you can sun yourself there on imported sand until September. Landlocked Birmingham, meanwhile, boasts access to several urban and pop-up beaches, including the “Costa del Solihull”.

Our demand for sand appears ever more insatiable. Can rampant sand extraction be curbed? A win-win solution is the use of waste plastic in making concrete. Research suggests small particles of plastic waste – “plastic sand” – can replace 10% of the natural sand in concrete, saving at least 800m tonnes per year. Another solution is more intelligent design: concrete structures are often over-engineered, incorporating beams that are thicker than necessary. A team at Cambridge University is using computer modelling to size concrete more efficiently and cut waste.

Aurora Torres warns that such measures will not eliminate the continuing need for sand mining on a vast scale and that stricter monitoring and enforcement in the developing world are required. “This is a hidden ecological disaster in the making,” she says. “We will be hearing a lot more about sand in the coming years.”