The final event of last year’s beach-volleyball world tour was held in Toronto, in September, in a parking lot at the edge of Lake Ontario. There’s a broad public beach nearby, but few actual beaches meet the Fédération Internationale de Volleyball’s strict standards for sand, so the tournament’s sponsor had erected a temporary stadium and imported thirteen hundred and sixty tons from a quarry two and a half hours to the north. The shipment arrived in thirty-five tractor-trailer loads.

I visited the site shortly before the tournament, and spoke with Todd Knapton, who was supervising the installation. He’s the vice-president of the company that supplied the sand, Hutcheson Sand & Mixes, in Huntsville, Ontario. He’s in his fifties, and he was wearing a white hard hat, a neon-yellow-green T-shirt, dark-gray shorts, and slip-on steel-toed boots. We walked through a gate and across an expanse of asphalt to a pair of warmup courts, which from a distance looked like enormous baking pans filled with butterscotch-brownie batter. “You want to see the players buried up to their ankles,” he said, and stuck in a foot, to demonstrate. “Rain or shine, hot or cold, it should be like a kid trying to ride a bicycle through marbles.”

Ordinary beach sand tends to be too firm for volleyball: when players dive into it, they break fingers, tear hamstrings, and suffer other impact injuries. Knapton helped devise the sport’s sand specifications, after Canadian players complained about the courts at the 1996 Olympic Games, in Atlanta. “It was trial and error at first,” he said. “But we came up with an improved recipe, and we now have a material that’s uniform from country to country to country, on five continents.” The specifications govern the shape, size, and hardness of the sand grains, and they disallow silt, clay, dirt, and other fine particles, which not only stick to perspiring players but also fill voids between larger grains, making the playing surface firmer. The result is sand that drains so well that building castles with it would be impossible. “We had two rainstorms last night, but these courts are ready to play on,” he said. “You could take a fire hose to this sand and you’d never flood it.”

Beach-volleyball promoters all over the world have to submit one-kilogram samples to Knapton for approval, and his office now contains hundreds of specimens. (He also vets beach-soccer sand for fifa.) Hutcheson doesn’t ship its own sand to events overseas, but Knapton and his colleagues often create courts in other countries, after sourcing sand where they can. He took off his hard hat and showed me the underside of the brim, on which he had recorded, in black Sharpie, the names and dates of big events they’ve handled, among them the Olympic Games in Sydney, Athens, Beijing, and London. (The sand for London came from Redhill, in Surrey; the sand for Athens came from Belgium.) The company’s biggest recent challenge was the first European Games, which were held in Baku, Azerbaijan, in 2015. Baku has beaches—it’s on a peninsula on the western shore of the Caspian Sea—but the sand is barely suitable for sunbathing, much less for volleyball. Knapton’s crew searched the region and found a large deposit with the ideal mixture of particle sizes, in a family-owned mine in the Nur Mountains, in southern Turkey, eight hundred miles to the west.

The mine is within shelling distance of the Syrian border. Knapton had planned to transport the sand across central Syria, through Iraq, around Armenia, and into Azerbaijan from the northwest, in two convoys of more than two hundred and fifty trucks each. But geopolitics intervened. “You can cross those borders only at certain hours of the day, and isis was making the guys antsy,” he said. “In the end, we said, ‘Well, we could have handled one war.’ ” Instead, Knapton and his crew bagged the sand in one-and-a-half-ton fabric totes, trucked it west to Iskenderun, and craned it onto ships. “We did five vessels, five separate trips,” Knapton said. “The route went across the Mediterranean, up the Aegean, through the Bosporus, across the Black Sea, and into Sochi.” From there, they took the sand by rail through Russia and Georgia, around Armenia, and across Azerbaijan. “The Syrian exodus was on at that time, and we saw people walking for their lives,” he said. “But these were the first-ever European Games, so everything had to be right.”

Sand covers so much of the earth’s surface that shipping it across borders—even uncontested ones—seems extreme. But sand isn’t just sand, it turns out. In the industrial world, it’s “aggregate,” a category that includes gravel, crushed stone, and various recycled materials. Natural aggregate is the world’s second most heavily exploited natural resource, after water, and for many uses the right kind is scarce or inaccessible. In 2014, the United Nations Environment Programme published a report titled “Sand, Rarer Than One Thinks,” which concluded that the mining of sand and gravel “greatly exceeds natural renewal rates” and that “the amount being mined is increasing exponentially, mainly as a result of rapid economic growth in Asia.”

Pascal Peduzzi, a Swiss scientist and the director of one of the U.N.’s environmental groups, told the BBC last May that China’s swift development had consumed more sand in the previous four years than the United States used in the past century. In India, commercially useful sand is now so scarce that markets for it are dominated by “sand mafias”—criminal enterprises that sell material taken illegally from rivers and other sources, sometimes killing to safeguard their deposits. In the United States, the fastest-growing uses include the fortification of shorelines eroded by rising sea levels and more and more powerful ocean storms—efforts that, like many attempts to address environmental challenges, create environmental challenges of their own.

Geologists define sand not by composition but by size, as grains between 0.0625 and two millimetres across. Just below sand on the size scale is silt; just above it is gravel. Most sand consists chiefly of quartz, the commonest form of silica, but there are other kinds. Sand on ocean beaches usually includes a high proportion of shell pieces and, increasingly, bits of decomposing plastic trash; Hawaii’s famous black sand is weathered fragments of volcanic glass; the sand in the dunes at White Sands National Monument, in New Mexico, is mainly gypsum. Sand is almost always formed through the gradual disintegration of bigger rocks, by the action of ice, water, wind, and time, but, as the geologist Michael Welland writes, in his book “Sand: The Never-Ending Story,” many of those bigger rocks were themselves formed from accumulations of the eroded bits of other rocks, and “perhaps half of all sand grains have been through six cycles in the mill, liberated, buried, exposed, and liberated again.”

Sand is also classified by shape, in configurations that range from oblong and sharply angular to nearly spherical and smooth. Desert sand is almost always highly rounded, because strong winds knock the grains together so forcefully that protrusions and sharp edges break off. River sand is more angular. William H. Langer, a research geologist who retired from the U.S. Geological Survey a few years ago and now works as a private consultant, told me, “In a stream, there’s a tiny film of water around each grain, so when the grains bang together there’s enough energy to break them apart but not enough to let them rub against each other.” The shape of sand deposited by glaciers and ice sheets depends partly on how far the sand was moved and what it was moved over. Most of the sand in the Hutcheson quarry is “sub-angular”: the grains have fractured faces, but the sharp edges have been partly abraded away. Sand that’s very slightly more smooth-edged is “sub-rounded.”

Aggregate is the main constituent of concrete (eighty per cent) and asphalt (ninety-four per cent), and it’s also the primary base material that concrete and asphalt are placed on during the building of roads, buildings, parking lots, runways, and many other structures. A report published in 2004 by the American Geological Institute said that a typical American house requires more than a hundred tons of sand, gravel, and crushed stone for the foundation, basement, garage, and driveway, and more than two hundred tons if you include its share of the street that runs in front of it. A mile-long section of a single lane of an American interstate highway requires thirty-eight thousand tons. The most dramatic global increase in aggregate consumption is occurring in parts of the world where people who build roads are trying to keep pace with people who buy cars. Chinese officials have said that by 2030 they hope to have completed a hundred and sixty-five thousand miles of roads—a national network nearly three and a half times as long as the American interstate system.

Windowpanes, wineglasses, and cell-phone screens are made from melted sand. Sand is used for filtration in water-treatment facilities, septic systems, and swimming pools. Oil and gas drillers inject large quantities of hard, round sand into fracked rock formations in order to hold the cracks open, like shoving a foot in the door. Railroad locomotives drop angular sand onto the rails in front of their wheels as they brake, to improve traction. Australia and India are major exporters of garnet sand, which is crushed to make an abrasive material used in sandblasting and by water-jet cutters. Foundries use sand to form the molds for iron bolts, manhole covers, engine blocks, and other cast-metal objects. I once visited a foundry in Arizona whose products included parts for airplanes, cruise missiles, and artificial hip joints, and I watched a worker pouring molten stainless steel into a mold that had been made by repeatedly dipping a wax pattern into a ceramic slurry and then into sand. The work area was so hot that I nervously checked my arm, because I thought my shirt was on fire. Factories that produce plate glass—by pouring thin layers of molten silica onto baths of molten tin—can be hotter.

In some applications, natural aggregate can be replaced by or supplemented with recycled materials, but the possibilities are limited. And efforts to reduce consumption are complicated by the fact that many environmentally desirable products and activities depend as heavily on aggregate as environmentally undesirable ones do: solar panels are made from silica and silicon; wind turbines are manufactured with foundry sand; autonomous electric vehicles need roads and highways, too.

Last summer, at a quarry in western Connecticut, I put my hand into a big pile of sand that was the pinkish-gray color of calamine lotion. In a couple of months, the pile was going to be trucked to New York City, eighty miles south, and spread on top of Wollman Rink for the annual Rolex Central Park Horse Show. (Afterward, the sand would be trucked back to the quarry, to be stored until the following fall.) Bill Stanley, a vice-president of the construction company that owns the quarry, told me, “We make a customized, proprietary blend of horse-footing sand, and we’re sending it all over New York State and out to the Rocky Mountains. People want it in Europe, too.” The color comes from a dye; fibres and other additives are mixed in as well, to create a material that is sufficiently yielding to protect the feet and legs of very large animals but firm enough to support running and jumping. (It’s too stiff for volleyball.)

There’s no single standard for equestrian sand; different producers have different recipes. The pile I stuck my hand into is known as a manufactured sand, because it was produced by crushing stone—in this case, dolomitic marble. The marble in the quarry is part of the Stockbridge Formation, which runs from eastern New York to Vermont. “You can’t really use it as building marble, because it’s too jointed,” Stanley said. “But it makes exceptionally high-quality sand. It’s all calcium carbonate and magnesium carbonate, and Portland cement chemically bonds with it. We sell it mostly for landscaping and for architectural concrete.” He drove me up a narrow access road to a spot overlooking the main pit. “We developed this quarry for sand,” he said. “Sand is something you’ve got to keep your eye on, to be sure you have a good, reliable source for the long term.” For many years, Stanley’s company bought large quantities of high-quality aggregate from a dredging operation off the southern end of Staten Island, not far from an entrance to New York Harbor, but that operation was shut down in 2015, amid concerns that the dredges were doing environmental damage to the seafloor.

One engineer I spoke to told me that transporting sand and stone for ordinary construction becomes uneconomical after about sixty miles, and that builders usually make do with whatever is available within that radius, even if it means settling for materials that aren’t ideal. In some places, though, there are no usable alternatives. Florida lies on top of a vast limestone formation, but most of the stone is too soft to be used in construction. “The whole Gulf Coast is starved for aggregate,” William Langer, the research geologist, told me. “So they import limestone from Mexico, from a quarry in the Yucatán, and haul it by freighter across the Caribbean.” Even that stone is wrong for some uses. “You can build most of a road with limestone from Mexico,” he continued, “but it doesn’t have much skid resistance. So to get that they have to use granitic rock, which they ship down the East Coast from quarries in Nova Scotia or haul by train from places like inland Georgia.” When Denver International Airport was being built, in the nineteen-nineties, local quarries were unable to supply crushed stone as rapidly as it was needed, so vast quantities were brought from a quarry in Wyoming whose principal product was stone ballast for railroad tracks. The crushed stone was delivered by a freight train that ran in a continuous loop between the quarry and the work site.

Deposits of sand, gravel, and stone can be found all over the United States, but many of them are untouchable, because they’re covered by houses, shopping malls, or protected land. Regulatory approval for new quarries is more and more difficult to obtain: people don’t want to live near big, noisy holes, even if their lives are effectively fabricated from the products of those holes. The scarcity of alternatives makes existing quarries increasingly valuable. The Connecticut quarry I visited is one of a number owned by Stanley’s company, and like many in the United States it’s in operation today only because it predates current mining regulations.

Stanley showed me an old tunnel, barely visible in the underbrush, through which miners in the nineteenth century hauled stone from the quarry’s original pit, on the other side of a tree-covered rise. (In those days, the principal product was lime, which was used to make mortar in the era before Portland cement.) The old pit was abandoned many years ago, and is now almost completely overgrown. “It looks like Jurassic Park,” Stanley said. The company is planning to resume excavation near that area, though, as other sources become depleted. Before the work can begin, a large colony of bats—which took over the tunnel when miners stopped using it—will have to be relocated to a cavelike bat hibernaculum, which the company will build on another part of the property, with guidance from the state’s Department of Energy and Environmental Protection.

Ten years ago, I spent a week in Dubai, which at the time was one of the fastest-growing cities in the world. Construction cranes and imported laborers were everywhere. The work went on all night, and the city’s extraordinary traffic congestion was continually being made worse by road-widening projects intended to relieve it. Exhaust from cars and trucks, in combination with wind-borne dust from the Arabian Desert and humid air from the Persian Gulf, formed a thick, phlegm-colored haze that made breathing unpleasant—an effect exacerbated by the ferocious heat. (Dubai gets so hot during the summer that many swimming pools are cooled, rather than heated.)

One day, I played golf with an Australian who worked for a major real-estate developer. The course, like Dubai itself, had been built on empty desert, and I commented that creating fairways and greens in such a forbidding environment must be difficult. “No,” the Australian said. “Deserts are easy, because you can shape the sand into anything you like.” The difficult parts, paradoxically, are the areas that are supposed to be sand: deserts make lousy sand traps. The wind-blown grains are so rounded that golf balls sink into them, so the sand in the bunkers on Dubai’s many golf courses is imported. Jumeirah Golf Estates—on the outskirts of the city, next to the desert—has two courses, Fire and Earth, both designed by Greg Norman. The sand in the bunkers on the Earth course is white (the most prized color for golf sand) and was bought from a producer in North Carolina. The sand on the Fire course is reddish brown—more like the desert across the road. Norman’s company bought it from Hutcheson, which mined it at its quarry in Ontario, sifted it to make it firmer than volleyball sand, kiln-dried it, dyed it, and loaded it onto a ship.

Unfortunately for Dubai’s builders and real-estate developers, desert sand is also unsuitable for construction and, indeed, for almost any human use. The grains don’t have enough fractured faces for concrete and asphalt, and they’re too small and round for water-filtration systems. The high-compression concrete used in Dubai’s Burj Khalifa, the world’s tallest structure, was made with sand imported from Australia. William Langer told me that other desert countries face similar shortages. “Mauritania is trying to catch up with the world,” he said. “They’ve got sand all over the place, but it isn’t good even for highway construction.” Stone is so scarce in Bangladesh that contractors commonly resort to making concrete with crushed brick.

When I was in Dubai, rich people from across the world were paying such absurdly high prices for its real estate that the government decided to create more of it. From a window in a restaurant on an upper floor of my hotel, seven hundred feet above the Persian Gulf, I looked down on two vast offshore land-creation developments: Palm Jumeirah and the World. Both are artificial archipelagos. From above, Palm Jumeirah resembles a palm tree with spreading branches, or maybe a trilobite fossil. The World consists of three hundred small islands arranged in clusters that (vaguely) suggest a Mercator projection of Earth. Creating so much artificial land required enormous shipments of quarried stone, from across the Emirates, as well as hundreds of millions of tons of sand, which foreign contractors dredged from the floor of the Gulf and heaped into piles. According to a U.N. report, the dredging “exhausted all of the marine sand resources in Dubai,” and also did extensive environmental damage. Seafloor dredging creates the undersea equivalent of choking sandstorms, killing organisms, destroying coral reefs and other habitats, and altering patterns of water circulation. In 2011, a British scientist who had studied the Dubai projects told Nature, “All the ecological trajectories are downhill.”

Dubai’s archipelago developments were profoundly affected by the global recession. Palm Jumeirah survived, and today its curving branches—roughly a hundred yards wide and edged by narrow artificial beaches—are covered with double rows of multimillion-dollar villas, as well as hotels, clubs, and shopping malls. But the World remains undeveloped and has essentially been abandoned, as have two other sites that were intended to be bigger versions of Palm Jumeirah. It seems unlikely that anything significant will ever be built on them, although if construction picks up elsewhere they could conceivably serve as (phenomenally expensive) aggregate mines, since marine sand can usually be used to make concrete, as long as it’s been rinsed sufficiently to remove all the salt and other undesirable materials.

Hurricane Sandy, the most destructive ocean storm ever to strike the Northeast, made landfall on October 29, 2012, near Brigantine, New Jersey, a town on a barrier island just north of Atlantic City. The resulting water surge flooded streets, subway tunnels, and buildings in New York and its suburbs; the storm knocked out power, and did more than sixty-five billion dollars’ worth of damage in a dozen states. (Among other alarming effects, it created twenty-foot waves in the middle of Lake Michigan, six hundred miles to the west.) The devastation in places like Brigantine—and in the Rockaways, in New York—was especially severe. I visited Brigantine two years after Sandy struck, and saw damaged houses that had been raised onto elevated concrete-block foundations in the hope of protecting them from future storm surges. Houses were still awaiting their turn with booked-up contractors; one looked like a doll house, because an exterior wall was missing, revealing the rooms inside.

The barrier island on which Brigantine sits is part of a semi-continuous chain of skinny, shifting accumulations of sand that lie a short distance offshore along much of the Gulf Coast and most of the way up the Eastern Seaboard. Robert S. Young, a geology professor at Western Carolina University, in North Carolina, told me recently, “When people first settled this country, nobody built on the barrier islands. They were too stormy, and they weren’t good places to live.” Today, however, many barrier islands are densely covered with houses—the biggest and the most expensive of which often have the greatest exposure to ocean storms, since they’re the ones with the best water views. The rapid growth in construction has been driven by lax land-use ordinances, below-market flood-insurance rates, the indomitability of the human spirit, and, mainly, the willingness of Congress to cover much of the cost when the inevitable occurs. “The Feds have poured in money over and over,” Young continued. “Folks will say to me, ‘Gosh, Robert, people must be crazy to rebuild their roads and homes again and again, after all the storms,’ and my answer is ‘No, they’re making a perfectly rational economic decision. We’re the crazy ones, because we’re paying for it.’ “

Congress responded to Sandy by passing the Disaster Relief Appropriations Act of 2013, also known as the Hurricane Sandy Supplemental bill. It allocated a little more than forty-nine billion dollars for a long list of relief efforts, including more than five billion for the Army Corps of Engineers. Much of the Corps’s money has been spent on dredging sand from the seafloor and piling it up on shorelines between oceanfront real estate and the water. “The federal government had been involved in similar projects over the past couple of decades,” Young said. “But the projects had become so expensive that money wasn’t really available anymore. Then, suddenly, after Sandy, they all became practical.” An executive of Great Lakes Dredge & Dock—the country’s largest dredging company, and the contractor on many Corps projects—told me that ships belonging to his company began restoring a storm-damaged beach seventy miles up the coast from Brigantine a week after Sandy. “That was actually a preëxisting contract,” he said. “But we really haven’t left New Jersey since then.”

This past October, I watched a Great Lakes crew working on Long Beach Island, a densely developed barrier island up the Jersey coast from Brigantine. The island is a little more than twenty miles long, and for most of that length it’s no wider than two or three residential blocks. The crew I watched was working on a beach in Harvey Cedars, a town near the island’s northern end. Two red-hulled dredging ships were anchored offshore—one in federal waters, three miles out, the other much closer. The far ship vacuumed sand from the ocean floor, fifty feet down, and when its hold was full it switched places with the near ship, which had pumped its own load into a submerged steel pipe that ran all the way to the beach. As the far ship filled, its hull slowly sank from view; as the near ship emptied, its hull slowly rose.

A dozen porpoises swam past, between the near ship and the shore. On the beach, a dark torrent of sand and seawater gushed from the open end of the pipe and through a cagelike screen—whose functions included filtering out unexploded surplus munitions, which the American military dumped in the ocean following the end of the Second World War. Dozens of wading gulls picked edible items from the slurry, and workers with bulldozers and bucket loaders shaped the pumped sand into an extension of the dune I was standing on. That dune, which rose more than twenty feet above the water, looked more like a levee than any natural beachscape. It was roughly trapezoidal in cross-section—a long, unbroken loaf of sand running most of the length of the island, with sprigs of beach grass growing in evenly spaced rows on top of the completed sections, like hair-transplant plugs. When the project began, some homeowners complained that the dune would block their view of the water—as was certainly the case in my ground-floor room at the Drifting Sands Oceanfront Motel, in Ship Bottom.

A woman watching the Great Lakes crew from the same spot told me that she owned one of the houses now protected by the dune. Her house was very large, and, like virtually all the houses closest to the ocean, it stood on what looked like a grove of buried telephone poles: a foundation made of wooden piles, whose purpose is to allow storm surges to pass under the habitable spaces. She said that the heavy machinery on the beach was making her whole house shake. That’s because vibrations were breaking the adhesion between the piles and the sand—an effect called liquefaction. Still, she said, the shaking didn’t bother her very much: “The spin cycle on my washing machine makes my house shake, too.”

Robert Young told me, “Storms are not a problem for barrier islands in their natural state. Think of the undeveloped portions of Fire Island. No one talks about beach erosion there, because in storms the beach doesn’t disappear—it just rolls landward. A storm will take sand from the front and blow it on top and across, and the island will grow on the back side. Barrier islands are dynamic systems, and they actually need storms, because plants and animals indigenous to the islands are adapted to them.”

The problems start when people begin to think of mutable landforms as permanent property. Building houses and creating artificial dunes to protect them are mutually reinforcing interventions, because the houses turn the dunes into necessities and the dunes make the houses seem rational. As in Dubai, the seafloor suffers. Offshore sand dredging has been described as “submerged, open-pit strip mining.” It directly kills organisms that live or feed on the seafloor, including sea turtles, and it stirs up clouds of fine particles, which can suffocate fish by clogging their gills. Young told me that most of the specific effects are still unmeasured and unknown, because the places from which sand is taken are hard to monitor. “They’re underwater and they’re three miles offshore,” Young said. “You can’t just send graduate students out there once a week to see how things are going.” Still, it was easy to tell that the dredges were having an impact: all those feasting gulls hadn’t gathered to eat sand. The Bureau of Ocean Energy Management, which is part of the Department of the Interior, funded surveys after Hurricane Sandy to collect core samples from the outer continental shelf. But the program’s purpose is to identify potential resources for beach nourishment, not to assess biological depredation.

I went back to the dune that evening. The Great Lakes crew was still there, a little farther up the shore, working under lights. The company’s dredges operate around the clock, seven days a week, all year long; they are expensive to run and leaving them idle is uneconomical. And the job is open-ended, since the artificial dune isn’t meant to be permanent: its purpose is to neutralize big waves by allowing them to consume it. The Corps expects to rebuild the entire system, from end to end, on a four-to-six-year cycle. The dredges I was watching were scheduled to move south, to Delaware, as soon as they’d finished on Long Beach Island, and then to begin working their way up the coast again. And then again, and then again after that—until either the money has run out or the ocean has risen too high to be held back by sand.