In early August 1997, Charles Moore found himself floating through the North Pacific in his Tasmanian-built catamaran. Moore, an oil heir, activist, and yachting captain, had just finished up a two-week race and was heading back from Honolulu to Santa Barbara, California, through what’s called a “gyre”—an area of the ocean like the Sargasso Sea, wrapped inside a giant weather spiral, that serves as a reservoir for flotsam. As he described it in a 2003 article for Natural History, the thousand-mile journey took him through an endless field of plastic—3 million tons of it in all, he guessed, in an area about the size of Texas. Everywhere he looked he saw debris: bottles, bottle caps, wrappers, fragments. And when he returned to this “Garbage Patch” a year later, he found a vast “plastic-plankton soup” and a litany of bigger objects: a volleyball, a cathode-ray tube for a 19-inch TV, a truck tire mounted on a steel rim, and a gallon bleach bottle so brittle that it crumbled in his hands.

Moore’s Garbage Patch would grow in size and fame in the years that followed. The plastic-plankton soup he’d first discovered in 1997—which oceanographer Curtis Ebbesmeyer dubbed the “Eastern Garbage Patch” or the “Pacific Garbage Patch”—gained notoriety in a 2006 series for the Los Angeles Times that won a Pulitzer Prize. Its area had doubled: Now the patch was “twice the size of Texas.” (Some reports went even bigger.) As coverage intensified—the patch’s media profile peaked between 2007 and 2009—the soup coalesced into a garbage landmass with a more official name: the “Great Pacific Garbage Patch.” In 2007, the San Francisco Chronicle called the patch “a massive, eternal, slowly swirling vortex of noxious garbage the size of a continent and the shape of death itself, just floating out there in the middle of the Pacific Ocean, mocking life, humanity, God.”

But the Great Pacific Garbage Patch has always been less substantial than it sounds, less an island in the ocean than a big idea that floats around inside our heads. It’s a throwback to the time when environmental threats were made of solid things—empty bottles, fishing nets, nuclear waste, canisters of slime—that could be gathered up and buried or incinerated. Today’s pollution, both in the air and in the ocean, blows and flows around the planet in clouds of tiny particles, as garbage in a gaseous state. It’s hard enough to grasp, let alone to manage.

In a way, that’s the very problem the Great Pacific Garbage Patch helped to solve, when the concept was invented. Like its mirror image, the hole in the ozone layer, the patch squeezed and flattened all our worries, sequestering them in a far-off region of the globe.

That’s how and why the patch came into being, both as a fully fledged idea and a media phenomenon, at the turn of the millennium. But its history stretches back much further. (I’ve drawn below from Peter G. Ryan’s “A Brief History of Marine Litter Research.”) Jules Verne described the mechanics of a proto–garbage patch 150 years ago. At one point in Twenty Thousand Leagues Under the Sea, the ship Nautilus passes through the quiet waters of the Sargasso Sea, “a perfect lake in the open Atlantic.” Major ocean currents spin around this area, Verne’s narrator explains, sweeping flotsam inward toward its cold and placid center. Picture the fragments of a cork, he says, swished around a vortex in a vase of water: They’ll float to the center, too.

Sure enough, the passengers aboard the Nautilus find a graveyard of organic detritus—“products of all kinds,” Verne writes, “trunks of trees torn from the Andes or the Rocky Mountains, and floated by the Amazon or the Mississippi; numerous wrecks, remains of keels, or ships’ bottoms, side planks stove in, and so weighted with shells and barnacles that they could not rise again to the surface.”

People knew that areas like the Sargasso, encircled by ocean currents, could serve as sinks for floating trash. Verne got his information from oceanographer Matthew Fontaine Maury, whose 1855 work, The Physical Geography of the Sea, described the Sargasso as “the general receptacle of the driftwood and seaweed of the Atlantic,” while noting the existence of an analogous region of the North Pacific. But these “receptacles” didn’t seem to worry anyone until the 1970s. (Verne himself posited that the garbage vortex might be a good thing, potentially serving as a source of energy, “prepared by far-seeing Nature for the moment when men shall have exhausted the mines of continents.”) Around the time of the first Earth Day and the creation of the Environmental Protection Agency—both took place in 1970—researchers began to notice that animals were eating bits of plastic. The Laysan albatross, a large seabird native to Hawaii, seemed especially inclined to fill its gut with bottle caps and other indigestible refuse. But those who cared to look found plastivores throughout the ocean ecosystem: plastic bag–consuming sea turtles, manatees that gobbled fishing lines, and fish that sucked up plastic pellets.

In 1972, two oceanographers from Woods Hole went to the Sargasso Sea, in the wake of the Nautilus, and discovered plastic particles littering its surface. Around the same time, adventurer Thor Heyerdahl wrote up his experiences crossing the Atlantic Ocean in a papyrus boat and noted his dismay at finding bits of tar and other garbage along the route. A third warning came from Elizabeth Venrick, a researcher based in California, who made a trip up to the North Pacific where she found “a startling array of man-made objects, even 600 miles from the next major civilization.” As scholar Kim De Wolff explains in her fascinating dissertation on the Great Pacific Garbage Patch, Venrick kept a “junk log” of her findings at sea: one day a floating coffee can, the next an old balloon, and so forth.

By the 1980s, people knew there was a problem with “marine debris.” Treaties were signed and laws were passed to restrict the dumping of plastic pellets and other chunky waste into the ocean. But interest in the issue waned, even as scientists came to understand that these bigger bits—the bottles and the fishing lines—made up less than half the problem. Ocean plastics were not inert, they realized, nor did they disintegrate and disperse as harmless water dust. Rather, they broke down into tiny pieces of plastic confetti that could soak up toxins and then make their way into the food chain. In other words, the floating coffee cans and old balloons were less of a threat than expansive clouds of plastic micro-garbage.

It was hard to picture micro-garbage, though, and very hard to see it with the naked eye. And it was even harder to imagine how something so diffuse could ever be cleaned up. The problem of marine debris became so abstract, in the 1990s, that it was, for a time, nearly forgotten.

Then came Moore’s discovery of the Garbage Patch, and all the breathless coverage that ensued. It was quickly understood to be a solid thing—like a rubbish reef, or an island where one could moor a ship. (A Russian outlet was the first to use the phrase “trash island,” according to Kim De Wolff, and that notion quickly spread.)

In fact, the Great Pacific Garbage Patch was barely visible, since it comprised mostly micro-garbage. It can’t be scanned by satellites, or scoped out on Google Earth. You could be sailing right through the gyre, as many have observed, and never notice that you’re in the middle of a death-shaped noxious vortex. The patch is such a wishy-washy phenomenon, with wishy-washy impacts, that its extent can’t be described with any certainty. (“No scientifically sound estimates exist for the size or mass,” notes the National Oceanic and Atmospheric Administration.) Nor is it a singular phenomenon: There are two separate garbage patches in the North Pacific, along with several others all around the world, including in the Sargasso Sea.

But Moore’s colorful description of the bigger objects that he’d found in 1998—the volleyball, the television, the bottle caps—provided the raw materials for a fantastical and disturbing image. It was as if the planet had swallowed up the greasy excess of consumer culture, and then left a pool of vomit in the middle of the ocean. It was this false appraisal—this projection of collective guilt as a trash archipelago—that brought the problem of marine debris back into the public eye. It gave us all a way to comprehend, or at least hallucinate, what was otherwise a widespread, microscopic devastation.

Moore tried to backtrack from the metaphor. He begins his 2011 memoir, Plastic Ocean, by touching up the image he’d helped create:

Let it be said straight up that what we came upon was not a mountain of trash, an island of trash, a raft of trash, or a swirling vortex of trash—all media-concocted embellishments of the truth. It would come to be known as the Great Pacific Garbage Patch, a term that’s had great utility, but, again, suggests something other than what’s out there. It was and is a thin plastic soup, a soup lightly seasoned with plastic flakes, bulked out here and there with “dumplings”: buoys, net clumps, floats, crates, and other “macro debris.” I was not a latter-day Columbus discovering a plastic continent.

This shift in focus—it’s not the dumplings, it’s the broth—was meant to reconstitute the problem. Moore didn’t want us all to fixate on a bunch of random crap, like the litter that washes up ashore on public beaches, so much as the global system of emissions. Sociologist and artist Max Liboiron described a similar attempt to tweak the language of the garbage patch as she churned through the gyre on a research ship. Meeting in the galley, the crew of 21 tried to figure out a way to talk about the micro-plastics problem that wouldn’t spawn ill-conceived ideas for how to fix it. They agreed to call the garbage plastic smog instead of plastic soup. “Our cities are the horizontal smokestacks pumping plastic into the ocean,” Liboiron wrote.

How we frame a problem colors how we think about solving it. (Or how not to solve it: If the Great Pacific Garbage Patch really were something like a floating landfill, then we might be wise to leave it where it lies. Would it really make sense to haul that garbage back to terra firma, just so we can dump it in a different concentrated landfill?) But a shift from plastic soup to plastic smog also undermines the metaphor that made the garbage patch compelling. If it’s just another form of invisible pollution, like the stuff that leads to global warming, then the problem starts to seem blurry and intractable.

Perhaps it’s best to leave the Great Pacific Garbage Patch as it is, where it is, in the shallows of the imagination. The same metaphor worked beautifully in the fight against depletion of the ozone layer. That problem, too, was first identified—and partially addressed through legislation—in the 1970s. But a few years later it was pushed aside. A 1984 report from the National Academies of Science found no trend of decreasing ozone, and the media declared the crisis over. The “great ozone scare” was even cited during early congressional hearings on global warming, as an example of alarmism.

Then in 1985, a team of British scientists in Antarctica published observations of a “hole” in the ozone layer. It wasn’t quite a hole, but a relative decrement in the quantity of local ozone near the South Pole during a particular time of year. Still, the global problem of chlorofluorocarbon emissions, leading to the degradation of the atmosphere, had been focused on a single spot. The gases coalesced into a thing that could be measured in a way we understood. How big is the hole in the ozone layer? It’s about 20 million square kilometers—the same size as the North Pacific Subtropical Gyre, home of the Great Pacific Garbage Patch. It’s as if a giant circle of confetti had been punched out of the sky, and fluttered down onto the surface of the ocean.

With the image of the ozone hole in place, efforts to resolve the problem moved quickly. Consumers turned against the use of CFC-emitting spray cans, and activists targeted McDonald’s for its use of clamshell packaging made with ozone-depleting chemicals. An international emissions treaty signed in 1987 codified the switch away from chlorofluorocarbons.

I suspect that visions of the garbage patch have likewise stirred up action on the oceans. A flock of states passed laws last year limiting the use of “plastic micro-beads,” millimeter-scale petrochemical pollutants, in personal cosmetics. A federal law quickly followed, with scarcely any opposition. The Microbead-Free Waters Act of 2015 “sailed through Congress in an age when most legislation plods,” the New York Times noted in amazement.

There are lots of reasons why fixes for the ozone hole and garbage patch were much more likely to be put in place than any cure for global warming, the great emissions crisis of our time. (They’re much smaller-scale and cheaper, for one thing.) Still, it could only help to have a better metaphor for climate change—something more evocative than the threat of shrinking ice caps, and longer-lasting than a violent storm. Scientists have already started dreaming of a way to gather up the world’s emissions into a single spot, hidden somewhere far away. Here’s one idea that’s been seriously considered: Suck up all the greenhouse gases from our smokestacks, compress them into liquid, and pour the liquid into lakes on the bottom of the ocean. The metaphor could become a literal solution: We’d have made a Giant Carbon Patch ourselves.