The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World
1. THE OLDEST STORY EVER TOLD
THE R/V KNORR was a storied ship in the annals of science, known for its ability to take a pounding in rough seas and its unusual arrangement of propellers in the bow and stern that made it highly maneuverable. Scientists had used the Knorr, a 244-foot steel-hulled research vessel that was operated by Woods Hole Oceanographic Institution, for thousands of research expeditions around the world, including one that led to the discovery of the wreck of the RMS Titanic. A few years ago, I spent a month aboard the Knorr. On my trip, we were looking for nothing more glamorous than good, thick mud on the floor of the North Atlantic. By drilling cores in the mud and analyzing the shells of creatures buried within it, researchers can better understand past ocean temperature and salinity, which are important as scientists attempt to reconstruct the history of the Earth’s climate.
Most of our time was spent cruising around the Bermuda Rise, a cluster of extinct underwater volcanos near Bermuda, pausing to take core samples of the mud whenever the conditions looked good. At one point, we were about a hundred miles off the coast of New York City when we drifted over a place known to scientists as the Hudson Canyon, which is where the Hudson River used to drop over the continental shelf twenty thousand years ago when seas were lower. From the ship, a device called an acoustic echo machine painted colorful real-time images of the canyon as we passed over it. It was a remarkable sight: you could see where the Hudson had cut a path through the shelf, creating terraces and high walls. The canyon extends over 450 miles across the shelf, eventually reaching a depth of over 10,000 feet. “It’s bigger than the Grand Canyon,” Lloyd Keigwin, the chief scientist on the trip, told me as I looked down in wonder.
Twenty thousand years ago, near the peak of the last ice age, the world was a very different place than it is today. Temperatures were about seven degrees Fahrenheit cooler and the climate was, in most places, drier. In North America, all the ice-age creatures we know and love from Ice Age, the movie—mammoths, sloths, saber-toothed tigers—roamed through the plains and forests. In the West, you could walk from what’s now San Francisco to the Farallon Islands. The Laurentide ice sheet, thousands of feet thick in places, covered most of Canada and the Upper Midwest and spread along the East Coast all the way to New York City. In Europe, it was dry land from London to Paris, and up north, from Scotland all the way over to Sweden. In Asia, you could walk from Thailand to Indonesia, and then take a boat down to Australia.
And people did. One wave of migration, as every American kid learns in middle school, brought humans across the land bridge between Asia and North America, thus laying the groundwork for the birth of Hollywood, Silicon Valley, and Ben & Jerry’s ice cream. Exactly why and when human beings made the trip across the land bridge in the first place is much debated. Until recently, the best guess for the date of the arrival of humans in North America was 13,200 years ago. Many anthropologists believed it couldn’t have been much earlier than that because although the land bridge was open, much of North America was covered in an ice sheet until then, making it virtually impossible for even the most intrepid early explorers to travel down into the interior of the continent.
But that narrative has been challenged. In 2012, Jessi Halligan, a young anthropologist at Florida State University, led a team of divers to explore the Aucilla River about seventy-five miles from Tallahassee. The Aucilla is a slow, dark, mysterious river that winds across northern Florida’s limestone plateau toward the Gulf of Mexico. Earlier archaeologists had pulled up boatloads of bison bones, saber-toothed tiger bones, and mastodon bones and tusks, some with markings that looked like humans could have made them. During the ice age, the sea had met the land a hundred miles farther out, and the area where the Aucilla now flows was high savannah. Springwater bubbled and pooled in the limestone, creating watering holes where animals gathered to drink. As the seas rose and the water backed up, these watering holes filled with sediment, covering and preserving the bones of the animals that had died along the waterholes.
In May of 2013, Halligan’s team made one of those scientific finds that change the way we view the world. In a sinkhole in the river, surrounded by mastodon dung, they found a two-faced knife that could only have been made by humans. More important, Halligan was able to precisely carbon-date the knife to 14,500 years ago.
14,500-year-old knife found in Florida’s Aucilla River. (Photo courtesy of the Center for the Study of the First Americans, Texas A&M University)
That finding is important in a number of ways. First, it is indisputable proof that humans were hanging around in Florida a thousand years earlier than had been previously understood. There was other evidence that humans had been in North America earlier, including artifacts at archaeological sites in places as far-flung as Oregon and Chile, but none were as solid as this one. Second, it suggests that these early immigrants were more creative and resourceful than researchers had previously understood. “We know that until about twelve thousand, six hundred years ago, the route from Alaska down to the interior of the continent was blocked by ice,” said Halligan. “The only way people could have gotten from Asia to this spot in Florida fourteen thousand, five hundred years ago that doesn’t involve time travel or teleporting is if they came by boat.” Halligan suggested they might have come down the West Coast, perhaps to Central America, then across the Gulf to Florida. If this is true, then these Paleolithic hunter-gatherers were building boats, understanding currents, navigating coastlines, and storing food and water. Of course, looking for evidence of this path down the coast is nearly impossible—many artifacts and campsites are now under three hundred feet or so of Pacific Ocean.
What is most important about this discovery—at least for the purposes of this book—is that the date of the double-sided knife corresponds with the sudden disintegration of the ice sheets at the end of the last ice age.
Scientists refer to the event as Meltwater Pulse 1A. It occurred just as the Earth was warming at the end of the last ice age. In coral reefs and other geologic sites around the world, scientists have seen that in the space of about 350 years, starting 14,500 years ago, the oceans began rising at a dramatic rate—more than a foot per decade. They know that this kind of sudden rise could only come from the collapse of a very big chunk of ice; the most likely candidates are the Laurentide ice sheet that covered North America and the glaciers of Antarctica. Scientists don’t know the mechanism for the collapse, whether it was the sudden breaking of a giant ice dam in North America that was holding back meltwater from the Laurentide, or warm ocean water getting up under the ice sheets of West Antarctica. But the geological evidence for the event itself is indisputable. It happened.
Due to the flat topography of coastal Florida, the rising seas would have been particularly dramatic to anyone living there. Halligan estimates that the seas moved inland at a rate of five hundred to six hundred feet a year. That’s a mile of coastline lost per decade—fast enough that you could almost watch the water come in while you gutted fish on the beach.
Halligan doubts that sea-level rise was the reason people abandoned the watering hole, since evidence so far suggests that the butchery at the site occurred over a very short period (they left no written accounts, which isn’t surprising, since writing hadn’t been invented yet). But whatever happened, it’s clear that rising seas were radically reshaping the world they lived in. And they weren’t the only ones who were dealing with it. At the time of Meltwater Pulse 1A, there were about three million people living on the Earth—nearly the population of Los Angeles today. They were living in small groups, making tools, hunting game, taking baby steps on the long ladder to modern life. What did they think about? What did they fear? Researchers can only make inferences from campsites, tools, and stray artifacts.
The most revealing clues, however, may come from the stories they left behind.
Nicholas Reid is an Australian linguist who studies the dying languages of Australian aborigines. Back in the 1970s, during his undergraduate days, he read a book called A Grammar of Yidi, about a nearly extinct aboriginal language spoken in northern Australia. For years, one particular sentence in the book stuck with him: “It is, however, worth noting that a theme running through all the coastal Yidinji myths is that the coastline was once where the barrier reef now stands (as in fact it was some 10,000 years ago), but the sea then rose and the shore retreated to its current position.” The idea lingered with Reid over the years. Was it possible that a ten-thousand-year-old event such as sea-level rise could be the basis for aboriginal myths?
In 2014, Reid mentioned the idea to a colleague, Patrick Nunn, a marine geologist who had studied sea-level rise in the Pacific. Nunn suggested that if the specifics in the myths were clear enough and detailed enough, they could be corroborated with geological data, allowing him and Reid to essentially date the origins of the myths.
Aboriginal societies have existed in Australia for around sixty-five thousand years, isolated until the European colonization of the continent in 1788. Australia was undoubtedly a hard environment to live in, and survival through the generations depended on passing down information about food, the landscape, and the climate. But that didn’t necessarily mean the stories the Aboriginals told were, after thousands of years of retelling, in any sense “precise.”
“It had long been assumed by linguists that the oldest oral stories are eight hundred years old—after that, any specific references in the stories are lost,” Reid explained to me. “How could a story be told accurately, over and over again, for ten thousand years?”
Still, it was a fascinating possibility. Reid began reading aboriginal myths, many of them collected in the late nineteenth and early twentieth centuries by Western researchers. Without trying too hard, he found twenty-one examples of stories about sea-level rise. Each one was different, but they seemed to be chronicling a time when the sea was rising and the people who lived on the coasts and the islands were grappling with how to deal with it. In regions of Australia where the coastal land had a low topography, even a small rise in sea level would have claimed large chunks of land relatively quickly. “People must have been aware that every year the sea was getting higher,” Reid said. “And they must have had stories from their fathers and grandfathers, and great-grandfathers, that the sea used to be out even further.”
Here is one example:
In the beginning, as far back as we remember, our home islands were not islands at all as they are today. They were part of a peninsula that jutted out from the mainland and we roamed freely throughout the land without having to get in a boat like we do today. Then Garnguur, the seagull woman, took her raft and dragged it back and forth across the neck of the peninsula, letting the sea pour in and making our homes into islands.
This story is about the origin of the Wellesley Islands off the northern coast of Australia, and it parallels other stories from other parts of Australia. Along the south coast, stories written down early in colonial times told about when these areas were dry, a time when people hunted kangaroo and emu there, before the water rose and flooded them, never again to recede.
“There are numerous Aboriginal stories from this area about a time when the shoreline was further out ‘where the barrier reef now stands,’” Reid told me. According to one of the stories, the barrier reef was the original coast at a time when a man called Gunya was living there. Gunya consumed a customarily forbidden fish, which made the gods angry. To punish him, they caused the sea to rise in order to drown him and his family. “He evaded this fate by fleeing to the hills but the sea never returned to its original limits,” Reid said.
Another story collected from the Yidinji people of the Cairns area—now a coastal town that is a frequent jumping-off point for expeditions to the Great Barrier Reef—recalls a time when Fitzroy Island, which is now a mile or so off the coast, was part of the mainland. The story describes several named landmarks with remembered historical-cultural associations that are now underwater. According to Nunn and Reid, based on the details in the story, researchers can be almost certain that the people of this area occupied the coast “where the Great Barrier Reef now stands” during the last ice age, when it was a broad floodplain with undulating hills, bordered by steep cliffs—which are now islands like Fitzroy.
“Our expectation originally was that the sea level must have been creeping up very slowly and not been noticeable in an individual’s lifetime,” Reid told me. “But we’ve come to realize through conducting this research that Australia must in fact have been abuzz with news about this. There must have been constant inland movement, reestablishing relationships with the country, negotiating with inland neighbors about encroaching onto their territory. There would have been massive ramifications of this.”
Still, the idea that these stories were a chronicling of actual events was remarkable. “If you are talking about ten thousand years, you are really talking about three hundred to four hundred generations,” Reid said. “The idea that you can transmit anything over four hundred generations is extraordinary.” But Reid believes a key feature of Australian Aboriginal storytelling culture—a “cross-generational cross-checking” process—could explain the stories’ endurance through the millennia. In this process, a father will pass down the story to his sons—and the son’s nephews and nieces will be responsible for ensuring that their uncle knows those stories correctly.
These stories, of course, tell us nothing about what these aboriginal tribes thought or felt about the seas rising around them. But they do capture how deeply significant and strange this experience must have been, how inexplicable.
The best-known flood story in the Western world, of course, is Noah’s. In the Old Testament, the story is told of how Noah builds an ark and loads all the animals into it so they can survive the flood that God sends to cleanse the Earth. In God’s view, there is just too much corruption and debauchery going on in his lovingly created paradise, and he has to do something about it. It’s a powerful story of sin and redemption, but it’s not original to the Old Testament. Most Biblical scholars believe that the story of Noah is based on an even earlier flood story in The Epic of Gilgamesh, which is the tale of the adventures of a Mesopotamian king that was written two thousand years before the Bible.
There is nothing in the Bible itself—or in Gilgamesh—that suggests these stories have anything to do with sea-level rise ten thousand years ago—or any other time. In both cases, the flood is caused by epic rains.
But two scholars think it’s more complex than that. William Ryan and Walter Pitman, both geologists at Columbia University, argue that Gilgamesh, as well as the later Noah flood story, are based on a real event that occurred in the Black Sea about seven thousand years ago, when the seas were still rising at the end of the last ice age. At the time, the Black Sea was an isolated freshwater lake, cut off from the Mediterranean Sea by a high, narrow strip of land in what is now Turkey. Small groups of people lived on the fertile land around it, fishing from small boats and experimenting with growing crops for food.
As the ice melted, the Mediterranean rose higher and higher, and by about 5600 BCE, it had risen to a point where it was 500 feet above the Black Sea. Then the strip of land between them collapsed, and the seawater flowed over it. So much water poured in so fast it cut a flume—now the Bosporus Strait—280 feet wide and 450 feet deep. Ryan and Pitman calculated that ten cubic miles of water rushed through each day, two hundred times what goes over Niagara Falls, enough to cover Manhattan each day with water a half mile deep. The level of the lake rose six inches a day, inundating the deltas and invading the flat river valleys—moving upstream as much as a mile each day. “It’s hard to imagine the terror of those farmers, forced from their fields by an event they could not understand, a force of such incredible violence that it was as if the collected fury of all the gods was being hurled at them,” Pitman and Ryan have written. “They fled with family, the old and the young, carrying what they could, along with fragments of other languages, new ideas, and new technologies gathered from around the lake.”
After two years, the lake water had risen 330 feet, until the lake was at the same level as the Mediterranean Sea. The people who had lived around the lake scattered to Europe and the Middle East, spreading their agricultural skills and know-how into the West and down into what became Mesopotamia, where stories of the flood became the basis for the flood story in Gilgamesh—and later, the Bible.
It’s not a thesis all scientists accept. Liviu Giosan of Woods Hole Oceanographic Institution and colleagues from the University of Bucharest drilled cores in the area, examining the sedimentary data near where the Danube River empties into the Black Sea. They found evidence that Black Lake/Sea water levels rose only about half as much as Ryan and his colleagues proposed and would have drowned only about 800 square miles of land (about half of Rhode Island), rather than the 25,000 square miles (more than the entire state of West Virginia) that Ryan and Pitman suggested.
“The Deluge,” from 19th-century French artist Gustave Doré’s illustrated edition of the Bible. (Photo courtesy of Wikimedia Commons)
However serious the Black Sea flood may have been, researchers will likely never know for sure whether or not it inspired the flood stories in Gilgamesh or the Bible. But it is certainly true that flooding was a frequent and destructive occurrence in the ancient world and a common metaphor for political and social dissolution. In both Gilgamesh and the Bible, the flood is a catastrophe—but it’s also a cleansing, and a way of preparing the fallen world for a new order to emerge.
Unlike other ice-age mammals, humans had adapted to a changing climate and rising seas pretty well. One group who probably managed this better than most was the Calusa, a Native American tribe who lived in South Florida until they were wiped out by smallpox-bearing Europeans in the eighteenth century. To get better insight into how they lived, I visited Mound Key Archaeological State Park, which is on an island on Florida’s Gulf Coast that was the ancient capital of the Calusa.
My guide was Theresa Schober, an archaeologist and former museum director who had been studying the Calusa for more than a decade. I met her at the boat launch at Lovers Key State Park near Fort Myers and we loaded our gear onto a sixteen-foot fishing boat that was piloted by a friend of hers. Schober, then forty-six, was tall and thin and muscular, with an infectious enthusiasm for Calusa lore. We sped across Estero Bay, dodging Jet Skis and other fishing boats beneath a sky that was full of the towering, tumbling clouds that Florida is so good at creating. From a distance, Mound Key looked like any other Florida island—low and green and peaceful. The only thing remarkable about it was that it was entirely artificial, an island built by the Calusa from their discarded seashells.
We approached the island through a tangle of mangroves, idling up a narrow channel that felt like a portal to another time. As Schober explained to me while we struggled out of the boat onto a small beach, Calusa meant “fierce people” in their language. No one knows exactly how long the Calusa lived in this region, but it was likely thousands of years. Their first European encounter was in 1513 with Ponce de León, the Spanish explorer who, legend has it, was in search of the Fountain of Youth. The Calusa attacked his ships and drove them away. Unwisely, he returned to the area nearly a decade later. The Calusa attacked again—this time, they shot de León with an arrow poisoned with the sap of the manchineel, an applelike tree that grows among the mangroves in Florida. The Spanish name for it is árbol de la muerte, or “tree of death,” because the sap contains nasty toxins, including an organic compound called phorbol. De León died a few weeks later in Puerto Rico.
I dug my heel into the sand on the beach, thinking I might see an ancient oyster shell. “You’ll have to go a little deeper,” Schober joked. It was hard to believe that this entire island—all 125 acres—was created by generations of early Americans tossing oyster and mussel shells out the back door of their palapas. It was basically a well-engineered dump. Hunter-gatherers left these shell middens, as they are called, all over the world, from Australia to Denmark. In Florida, there are middens on both coasts and alongside most rivers. Many coastal middens are underwater or have been destroyed by development. But Mound Key, Schober explained, was in pretty good shape.
As we headed down a path through the mangroves, Schober told me that when the Spanish arrived, there were about a thousand people living on and around the island. But they were hardly isolated. They traded furs, food, glass beads, and other goods with neighboring tribes—there’s even evidence that they canoed all the way to Cuba.
“Did they leave behind any art? Any stories?”
“Nothing,” Schober said. “They were wiped out. These middens are it.”
After hiking for twenty minutes or so, we came to what looked like a wide, shallow ditch cutting across the trail. “This was the grand canal,” she explained. “The Calusa were very good at engineering with water. They built canals, with locks to control the water, as well as big water courts that functioned like a city square. Water was not something they resisted—it was deeply a part of their lives.”
“The Pinelands Site,” by Florida artist Dean Quigley. Early Floridians like the Calusa were well adapted to living with water. (Illustration courtesy of Dean Quigley)
Of course, the Calusa were not the only people who knew how to live with water. In New England, Native Americans lived in wood-framed houses that were covered with grass mats or bark so they could be taken down and transported by water. In parts of Newfoundland, a practice called launching is still common: when the waters rise or the shore changes, houses are dragged on wooden sleds to new locations. During the Revolutionary War, Tories escaping from Maine brought their houses with them to New Brunswick, where they still line the harbor. Houses on Cape Cod were also moved and recycled. One observer found that the residents thought of their “houses less as family seats, founded for the ages, than as temporary shelters, like the borrowed shells of hermit crabs, to be shifted about and exchanged, in location and function, as the need arose.”
Much of this is forgotten knowledge now.
“I was living here in South Florida when Hurricane Charley came through,” Schober said. Charley was a Category 4 hurricane that blew through the area in 2004. “People lost power, couldn’t get gas for their cars. It was a total disaster for lots of people.” Schober pointed out that the Calusa had to deal with hurricanes and storms too, but for them, it was probably not a big deal. “They just rebuilt their homes; it was part of their lives. If the storm changed the shoreline, that was how it was. If it blew over their huts, they could rebuild them. I don’t think they had a sense of permanence, a sense that their world was settled. Their world was changing every day.”
We left the canal and climbed a narrow trail through the mangroves to the top of the midden, which was about thirty feet high. In South Florida, that feels like Mount Everest. “The chief’s house would have been up here,” Schober explained. “The higher your house, the more prestigious it was—just like in cities today.”
It was an oddly hopeful moment: here I was, standing on an artificial island built by Calusa a thousand years ago, one oyster shell at a time. Schober explained how the shells interlocked and calcified together over time, creating a solid structure that has survived for thousands of years. It was not just a monument to human ingenuity, but also a sign that living with water is something our ancestors have been doing for a very long time. Of course, the Calusa didn’t have to worry about salt water corroding electrical wiring, or property values crashing, or nuclear power plants melting down as they got swamped by rising seas.