The Washington PostDemocracy Dies in Darkness

How climate change destroyed Britain’s ‘Atlantis’

Professor David Sear from the University of Southampton took sonar readings of the ruins of an old city destroyed by climate change off the coast of Dunwich. (Video: David Sear/University of Southampton)

There was an entire city out there, David Sear knew.

Beyond the faded town and crumbling cliffside, past the skeleton of a long-abandoned church that was itself just one strong storm away from tumbling into the water, through the sand and scrubby sea grass and under the waves, lay the remains of a British Atlantis. There were shipyards and guild halls, mansions and market squares, two friaries, six or seven churches, an untold number of homes.

Sear, a small child on vacation with his family, would perch on the ruins of the old church and listen for the bells that people said could still be heard tolling from the city’s submerged steeples.

He never heard them. But he never gave up trying to imagine the marine metropolis just off shore.

Several decades later, Sear is a professor of physical geography at the University of Southampton and the lead researcher on an effort to reconstruct what happened to the sunken city of Dunwich, England, where he spent so many childhood vacations. The venture has involved poring over 900-year-old tax records from dusty old archives, examining marsh cores in florescent-lit labs, diving into the murky waters of the North Sea to map with sound ruins that can’t be seen. It’s part science project, part historical investigation, part archaeology dig, Sear said.

Put the pieces all together, “and you get this 900-year story of a coastal settlement being affected by climate change,” he told The Washington Post on Tuesday.

Once among the most important cities in England, Dunwich was the victim of ferocious storms that lashed Britain’s eastern coast as Europe’s climate cooled going into the period now known as “the Little Ice Age.” Sonar maps, sediment samples and contemporary accounts revealed how the successive storms eroded the cliff the city once stood on, destroyed its economy and ultimately demoralized its inhabitants so thoroughly they all moved away.

Dunwich’s decline offers a fascinating history lesson, Sear said, but it’s also something of a cautionary tale. What happened to Dunwich may presage the fate of coastal communities being affected by climate change today.

But that’s where the story of Dunwich ends. It begins some 2,300 years ago, on the cliffs 115 miles northeast of London, overlooking the chilly North Sea.

A neolithic scraper and shards of Anglo-Saxon pottery uncovered during a dig last year revealed that Dunwich (pronounced “dun-itch”) was settled well before its medieval heyday. The dig was organized by the same Touching the Tide project that has helped fund the last three years of Sear’s research. Sear puts the start date for the settlement around 300 B.C., during the Iron Age.

For centuries after that, Dunwich remained more or less a sleepy seaside town. A 1086 accounting in William the Conqueror’s “Domesday Book” put the city at just one church, Sear said — in those days, the number of churches was more or less a direct reflection of a place’s cosmopolitanism.

But a few decades later, the city took off. By the 13th century, Dunwich was among the top six biggest ports in Britain. Its fishing fleet practically circumnavigated the country, its harbor sent ships around the continent. The city was to medieval Britain what the port of New Orleans is to the United States today — a hub of activity, culture and commerce.

“But around 1250, things started to go a bit wrong,” Sear said.

He can tell from requests for tax relief sent by town officials to the British crown. Year after year, Dunwich seemed unable to pay its usual amount — a storm had damaged the harbor, the letters said, or battered its ships.

A New Year’s tempest in 1287 shifted the city’s coastline, sending water pouring into the town and buildings plummeting into the sea. Another huge storm hit a few decades later, in 1347. Water and waves eroded the cliff face and demolished at least 20 percent of the town, Sear said. Hundreds of houses were lost, as were several churches. And the storm surge was so dramatic that it shifted a huge mass of sand until it blocked the harbor entrance. Dunwich had just been pulverized, and it had lost the means to recover.

These were the worst storms to hit during Dunwich’s trouble years, but they were not the only ones.  As the decades went on and as Europe transitioned out of a relatively warm period known as the “medieval climactic anomaly” and into the cooler times of “the Little Ice Age,” unstable conditions in the North Atlantic contributed to increasingly severe and increasingly common storms.

With each century, more and more of the Dunwich coastline was swept into the sea. In 1740, “inundations” from a particularly bad storm ripped open the Dunwich cliff where one of the medieval city’s many churches stood, tossing the chapel, the churchyard and its buried inhabitants into the waves.

“The sea raged with such fury that Cock and Hen hills which the preceding summer were upwards of 40-ft high had their heads leveled … and the ground all about them rent and torn,” the city’s mayor, Thomas Gardner, observed. “The foundations of St Francis chapel, which had lain between the hills, and the secret repositories of the dead were exposed to open view, several skeletons on the ooze, divested of their coverings, some keeping in pretty good order, others scattered as the surges carried them.”

“Imagine something like a hurricane hitting the coast and removing 20 percent of an international port including iconic buildings,” Sear explained. “That would be a shocking thing to happen, wouldn’t it?”

“Now imagine getting another storm the next year. And the next one. And the next one.”

Eventually, the community began to give up. Fishermen moved elsewhere, traders sought new ports, the monks abandoned their ruined monasteries.

“And they leave, and so Dunwich dwindles,” Sear said. “Eventually, it’s a collection of ruins.”

Historians knew the basic outline of this story even in the 1960s, when Sear visited with his family. But they didn’t know why it happened, or the extent of what was lost.

Sear and his colleagues have been working to give detail to the saga of Dunwich’s decline, filling in the holes in the narrative he’d been told as a boy. For example, what caused the terrible storms that started in the 13th century? How do we know that they were really so severe? How did the people of Dunwich respond? What’s left of the city they once inhabited? Is there anything those ruins can still tell us?

They made the connection between Europe’s cooling climate and the increased intensity of Dunwich’s storms at the end of the medieval era. They also corroborated the contemporary accounts of the storms with soil samples from the nearby marshes: for every year in which Dunwich residents described particularly bad weather, Sear said, he and his colleagues found excess sand in the cores that had clearly been blown in by the storm.

Biggest of all was their extensive, underwater map of Dunwich’s ruins, which they published in 2013. Using acoustic imaging — technology not so different from the kind used in an ultrasound — they found the ruins of the city’s churches, markets and shipyards, all of it exactly where medieval accounts said it should be.

Meanwhile, pollen analysis revealed how people “gave up on Dunwich,” Sear said — showing a decline in food production as the city’s population dwindled.

It’s a lesson in how communities respond when their environment is irrevocably altered. Sear compared Dunwich to New Orleans after Hurricane Katrina.

“What would happen if the city got hit by another hurricane, and then another?” he said. “Communities respond well to one-off big events. They pull together, and the nation can help and the region can help.”

“But when a community is faced by an increased frequency, that’s when it has to make a difficult decision,” he continued. “It’s hard to keep saying, ‘We’re going to stick this out.'”

Most of Dunwich didn’t. Now just 100 or so people leave in the tiny community, which is so small it doesn’t even have a parish council — just a town meeting any resident can attend.

And the town is still taking a lashing. The ruins of All Saints Church, where Sear once sat as a boy and listened for phantom bells, have since been buried in a sand bank just off the beach.

Now a single tombstone from the building’s churchyard is all that remains.

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