Field Notes From a Catastrophe: Man, Nature, and Climate Change (13 page)

DeMenocal also recalls his subsequent dismay when he went to learn more. “It struck me that they were calling on this climate-change argument, and I wondered how come I didn’t know about it,” he said. He looked at the
Science
paper in which Weiss had originally laid out his theory. “First of all, I scanned the list of authors and there was no paleoclimatologist on there,” deMenocal said. “So then I started reading through the paper and there basically was no paleoclimatology in it.” (The main piece of evidence Weiss adduced for a drought was that Tell Leilan had filled with dust.) The more deMenocal thought about it, the more unconvincing he found the data and the more compelling he found the underlying idea. “I just couldn’t leave it alone,” he told me. In the summer of 1995, he went with Weiss to Syria to visit Tell Leilan. Subsequently, he decided to do his own study to prove—or disprove—Weiss’s theory.

Instead of looking in, or near, the ruined city, deMenocal focused on the Gulf of Oman, a thousand miles downwind. Dust from the Mesopotamian floodplains, just north of Tell Leilan, contains heavy concentrations of the mineral dolomite, and since arid soil produces more wind-borne dust, deMenocal figured that if there had been a drought of any magnitude it would show up in gulf sediments. “In a wet period, you’d be getting none or very, very low amounts of dolomite, and during a dry period you’d be getting a lot,” he explained. He and a graduate student named Heidi Cullen developed a highly sensitive test to detect dolomite, and then Cullen assayed, centimeter by centimeter, a sediment core that had been extracted near where the Gulf of Oman meets the Arabian Sea.

“She started going up through the core,” deMenocal told me. “It was like nothing, nothing, nothing, nothing, nothing. Then one day, I think it was a Friday afternoon, she goes, ‘Oh, my God.’ It was really classic.” DeMenocal had thought that the dolomite level, if it were elevated at all, would be modestly higher; instead, it went up by 400 percent. Still, he wasn’t satisfied. He decided to have the core reanalyzed using a different marker: the ratio of strontium 86 and strontium 87 isotopes. The same spike showed up. When deMenocal had the core carbon-dated, it turned out that the spike lined up exactly with the period of Tell Leilan’s abandonment.

Tell Leilan was never an easy place to live. Much like, say, western Kansas today, the Khabur plains received enough annual rainfall—about seventeen inches—to support cereal crops, but not enough to grow much else. “Year-to-year variations were a real threat, and so they obviously needed to have grain storage and to have ways to buffer themselves,” deMenocal observed. “One generation would tell the next,‘Look, there are these things that happen that you’ve got to be prepared for.’ And they were good at that. They could manage that. They were there for hundreds of years.”

He went on, “The thing they couldn’t prepare for was the same thing that we won’t prepare for, because in their case they didn’t know about it and because in our case the political system can’t listen to it. And that is that the climate system has much greater things in store for us than we think.”

Shortly before Christmas 2004, Harvey Weiss gave a lunchtime lecture at Yale’s Institute for Biospheric Studies. The title was “What Happened in the Holocene,” which, as Weiss explained, was an allusion to a famous archaeology text by V. Gordon Childe, titled
What Happened in History
. The talk brought together archaeological and paleoclimatic records from the Near East over the last ten thousand years.

Weiss, who is sixty years old, has thinning gray hair, wire-rimmed glasses, and an excitable manner. He had prepared for his audience—mostly Yale professors and graduate students—a handout with a time line of Mesopotamian history. Key cultural events appeared in black ink, key climatological ones in red. The two alternated in a rhythmic cycle of disaster and innovation. Around 6200 B.C., a severe global cold snap—red ink—produced aridity in the Near East. (The cause of the cold snap is believed to have been a catastrophic flood that emptied an enormous glacial lake—Lake Agassiz—into the North Atlantic.) Right around the same time—black ink—farming villages in northern Mesopotamia were abandoned, while in central and southern Mesopotamia the art of irrigation was invented. Three thousand years later, there was another cold snap, after which settlements in northern Mesopotamia once again were deserted. The most recent red event, in 2200 B.C., was followed by the dissolution of the Old Kingdom in Egypt, the abandonment of villages in ancient Palestine, and the fall of Akkad. Toward the end of his talk, Weiss, using PowerPoint, displayed some photographs from the excavation at Tell Leilan. One showed the wall of a building—probably intended for administrative offices—that had been under construction when the rain stopped. The wall was made from blocks of basalt topped by rows of mud bricks. The bricks gave out abruptly, as if construction had ceased from one day to the next.

The monochromatic sort of history that most of us grew up with did not allow for events like the drought that destroyed Tell Leilan. Civilizations fell, we were taught, because of wars or barbarian invasions or political unrest. (Another famous text by Childe bears the exemplary title
Man Makes Himself
.) Adding red to the time line points up the deep contingency of the whole enterprise. Civilization goes back, at the most, ten thousand years, even though, evolutionarily speaking, modern man has been around for at least ten times that long. The climate of the Holocene was not boring, but it was dull enough to allow people to sit still. It was only after the immense climatic shifts of the glacial epoch had run their course that agriculture and writing finally emerged.

Nowhere else does the archaeological record go back so far or in such detail as in the Near East. But similar red-and-black chronologies can now be drawn up for many other parts of the world: the Indus Valley, where, some four thousand years ago, the Harappan civilization suffered a decline after a change in monsoon patterns; the Andes, where, fourteen hundred years ago, the Moche abandoned their cities in a period of diminished rainfall; and even the United States, where the arrival of the English colonists on Roanoke Island, in 1587, coincided with a severe regional drought. (By the time English ships returned to resupply the colonists, three years later, not a single one was left.) At the height of the Mayan civilization, population density was five hundred per square mile, higher than it is in most parts of the United States today. Two hundred years later, most Mayan territory had been completely depopulated. You can argue that man through culture creates stability, or you can argue, just as plausibly, that stability is for culture an essential precondition.

After the lecture, I walked with Weiss back to his office, which is near the center of the Yale campus, in the Hall of Graduate Studies. In 2004, Weiss decided to suspend excavation at Tell Leilan. The site lies only fifty miles from the Iraqi border, and, owing to the uncertainties of the war, it seemed like the wrong sort of place to bring graduate students. When I visited, Weiss had just returned from a trip to Damascus, where he had gone to pay the guards who watch over the site when he isn’t there. While he was away from his office, its contents had been piled up in a corner by repairmen who had come to fix some pipes. Weiss considered the piles disconsolately, then unlocked a door at the back of the room.

The door led to a second room, much larger than the first. It was setup like a library, except that instead of books the shelves were stacked with hundreds of cardboard boxes. Each box contained fragments of broken pottery from Tell Leilan. Some were painted, others were incised with intricate designs, and still others were barely distinguishable from pebbles. Every fragment had been inscribed with a number, indicating its provenance.

I asked what he thought life in Tell Leilan had been like. Weiss told me that that was a “corny question,” so I asked him about the city’s abandonment. “Nothing allows you to go beyond the third or fourth year of a drought, and by the fifth or sixth year you’re probably gone,” he observed. “You’ve given up hope for the rain, which is exactly what they wrote in ‘The Curse of Akkad.’ ” I said I would like to see something that might have been used in Tell Leilan’s last days. Swearing softly, Weiss searched through the rows until he finally found one particular box. It held several potsherds that appeared to have come from identical bowls. They were made from a greenish-colored clay, had been thrown on a wheel, and had no decoration. Intact, the bowls had held about a liter, and Weiss explained that they had been used to mete out rations—probably wheat or barley—to the workers of Tell Leilan. He passed me one of the fragments. I held it in my hand for a moment and tried to imagine the last Akkadian who had touched it. Then I passed it back.

Chapter 6

Floating Houses

In February 2003, a series of ads on the theme of inundation began appearing on Dutch TV. The ads were sponsored by the Netherlands’ Ministry of Transport, Public Works, and Water Management, and they featured a celebrity weatherman named Peter Timofeeff. In one commercial, Timofeeff, who looks a bit like Albert Brooks and a bit like Gene Shalit, sat relaxing on the shore in a folding chair. “Sea level is rising,” he announced, as waves started creeping up the beach. He continued to sit and talk even as a boy who had been building a sand castle abandoned it in panic. At the end of the ad, Timofeeff, still seated, was immersed in water up to his waist. In another commercial, Timofeeff was shown wearing a business suit and standing by a bathtub. “These are our rivers,” he explained, climbing into the tub and turning on the shower full blast. “The climate is changing. It will rain more often, and more heavily.” Water filled the tub and spilled over the sides. It dripped through the floorboards, onto the head of his screeching wife below. “We should give the water more space and widen the rivers,” he advised, calmly reaching for a towel.

Both the beach chair and the shower ads were part of a public-service campaign titled, somewhat ambiguously, “
Nederland Leeft Met Water
” (“The Netherlands Lives with Water”), which also included radio spots, free tote bags, and newspaper announcements drawn in the form of cartoons. Its tone was consistently lighthearted—other commercials showed Timofeeff trying to start a motorboat in a cow pasture and digging a duck pond in his backyard—either in spite of the fact that, or maybe precisely because, its message for the Dutch was so devastating.

Fully a quarter of the Netherlands lies below sea level, on land wrested from either the North Sea or the Rhine or the Meuse Rivers, or one of the hundreds of natural lakes that once dotted the countryside. Another quarter, while slightly higher, is still low enough that, in the natural course of events, it would regularly be flooded. What has made this arrangement possible is the world’s most sophisticated water management system, which, according to government figures, comprises 150 miles of dunes, 260 miles of sea dikes, 850 miles of river dikes, 610 miles of lake dikes, and 8,000 miles of canal dikes, not to mention countless pumps, holding ponds, and windmills.

Historically, whenever flooding has occurred, the Dutch response has been either to reinforce the dikes or to add new ones. In 1916, for example, after the defenses gave out along an inlet of the North Sea known as the Zuiderzee, the Dutch dammed up the Zuiderzee, creating an artificial lake as large as Los Angeles. In 1953, storms overwhelmed the dikes in the province of Zeeland, killing 1,835 people. Immediately afterward, the government embarked on a massive, five-and-a-half-billion-dollar construction project known as the Delta Works. (The last phase of the project, the Maeslant barrier, which was finally completed in 1997, is supposed to protect Rotterdam from storm surges with the aid of two moveable arms, each the size of a skyscraper.) People in Holland like to joke, although they are not really joking, “God made the world, but the Dutch made the Netherlands.”

“The Netherlands Lives with Water” signals the end of this five-hundred-year project. Looking ahead, the same engineers who built the Maeslant barrier have determined that even such monumental public works projects are no longer adequate. From now on, instead of reclaiming land from the water, the Dutch, they have decided, are going to have to start giving back.

The Nieuwe Merwede looks like a river, but is actually a canal, dug in the 1870s in the delta of the Rhine and Meuse Rivers. It runs on a winding course west from the city of Werkendam until it meets up with another man-made river to form what is known as the Hollandsch Diep, which, in the confusion of the delta, splits again, and eventually empties into the North Sea.

On the north side of the canal, in a pocket-sized national park called Biesbosch, is a nature center, which, at the time that I visited, was running an exhibit on climate change. By way of decoration, large black umbrellas had been hung from the ceiling, and in the background, the soundtrack of a church bell—the traditional Dutch flood warning—tolled periodically. One kid-friendly display allowed visitors to turn a crank and, in effect, drown the countryside. By 2100, the display showed, the Nieuwe Merwede will be running, at peak flows, several feet above the top of the local dikes.

There are several reasons why global warming produces flooding. The first has to do simply with the physics of liquids. As water warms, it expands. In a small body of water, the effect is small; in a big body, it’s commensurately larger. Most of the sea level rise predicted for the next hundred years—a total of up to three feet—is purely a function of thermal expansion. (Even if greenhouse gas levels are eventually stabilized, sea levels will continue to rise for several centuries, owing to the oceans’ thermal inertia.)

Meanwhile, a warming Earth means changing precipitation patterns. Just as some regions, like the American Midwest, are predicted to suffer from drought, others will experience more—or at least more intense—rainfall. The effect is likely to be particularly punishing in some of the most densely populated regions on Earth, including the Mississippi Delta, the Ganges Delta, and the Thames basin. A study commissioned a few years ago by the British government concluded that under certain conditions, floods of a magnitude now expected no more often than once a century could, by 2080, be occurring in England once every three years. (As it happened, the very week I was in the Netherlands, thirteen people were killed by exceptionally heavy winter storms in Britain and Scandinavia.)