Brian Fagan, 
Floods, Famines, and Emperors: El Niño and the Fate of Civilizations
(Basic Books, 1999). 

 (  And if you want to read the full-scale treatment, see Fagan's The Little Ice Age (Basic Books, 2000).  Copyright 1999 Brian Fagan.


The Little Ice Age



I came to an immense mass of ice . . . . It was two or three pikes thick, and as wide as the range of a strong bow. Its length stretched indefinitely inwards, so you could not see its end. To anyone look­ing . . . it was a horrifying spectacle, its horror enhanced by one or two blocks the size of a house which had detached themselves from the main mass.

-Sebastian Munster, on a Rhone glacier, August 4, 1546



Only 150 years ago, Europe came to the end of a 500 year cold snap so severe that thousands of peasants starved. The Little Ice Age changed the course of European history. Dutch canals froze over for months, shipping could not leave port, and glaciers in the Swiss Alps overwhelmed mountain villages. Five hundred years of much colder weather changed European agriculture, helped tip the balance of political power from the Mediterranean states to the north, and con­tributed to the social unrest that culminated in the French Revolu­tion. The poor suffered most. They were least able to adjust to changing circumstances and most susceptible to disease and increased mortality. These five centuries of periodic economic and so­cial crisis in a much less densely populated Europe are a haunting reminder of the drastic consequences of even a modest cooling of global temperatures.

The Little Ice Age was the most recent of three relatively long cold snaps during the past ten thousand years. The Younger Dryas that triggered agriculture in southwestern Asia was the most severe, for it brought glacial conditions back to Europe. Another cold snap in about 6200 B.C. lasted four centuries and caused widespread drought. The Little Ice Age had more impact on history than its two predecessors, for it descended on the world after centuries of unusually warm temperatures. One can reasonably call it the mother of all history-changing events.

El Niños have destroyed civilizations and caused unimaginable suf­fering for at least five thousand years. They lie at one end of the climate-change spectrum -- short, often severe events that roll across the tropical regions of the world and leave destruction in their path. By overthrowing powerful rulers and entire societies, such events have been as dramatic in their historical impact at the local level as the much longer climatic oscillations, measured in centuries, that have affected entire continents. All these fluctuations, whether El Niños or La Niñas, cycles of unusually stormy weather, or suddenly much colder temperatures, are part of a complex global climatic machine that in­cludes oscillations on all scales. We know the machine is driven at least partially by complex interactions between the atmosphere and the oceans, and by deep-ocean circulations that transfer warm and cold water from the tropics to higher latitudes and back again. But many of the connections between such phenomena as El Niño and longer-term cycles such as the Little Ice Age remain a complete mystery.

This chapter changes climatic gears and tells the story of four cen­turies of unusually cold weather that altered the course of European history. The Little Ice Age operated on a different scale from a short­-lived El Niño; it danced to a different climatic drummer than the pro­tean Christmas Child. We do not know what caused this, or earlier, cold snaps, beyond a suspicion that deep-ocean circulations and arctic downwelling were important parts of the climatic equation. We know more about the causes of El Niños than we do about the much longer Little Ice Age.

The Little Ice Age was not a monolithic deep freeze, but a period of constant, and sometimes remarkable, climatic shifts between torrid summers and subzero winters. Like the Pacific, the Atlantic has a pressure oscillation of its own. A high North Atlantic Oscillation pressure gradient brings rain, strong westerly gales, and warmer temperature Cold years come when the North Atlantic Oscillation is low. These periods of warmer and colder conditions, which came and went Burin the Little Ice Age with unpredictable rapidity, were caused by complex and still little-studied phenomena such as movements of the Intertropical Convergence Zone at the equator and complex atmospheric rote actions in the tropical Atlantic and Pacific. In another generation many of these subtle teleconnections will be better understood. We will then discover whether the constant seesaw of the Southern Oscillation on the other side of the world played a role in shaping European history. In the meantime, the four centuries of the Little Ice Age offer a instructive lesson in the ability of long-term climatic oscillations change the course of history in both gradual and sudden ways.


As Maya civilization collapsed in A.D. 900 and the Anasazi suffered through the great drought of the twelfth century, Europe enjoyed five and a half centuries of warmer temperatures and ample rainfall, commonly called the Medieval Warm Period. Average temperatures in the British Isles between 1140 and 1300 were up to 0.8 degrees C higher than those of 1900 to 1950. Only today are some summer temperatures reaching Medieval Warm Period levels.

Greenland ice sheets tell us there was a burst of warmer weather the far north between A.D. 600 and 650, followed by a more pr longed warm period that began about 800 and climaxed between 1150 and 1300. Norwegian farmers grew wheat north of Trondheim at an unprecedented sixty-four degrees north. English vintners planted grapes as far north as Herefordshire in western England at altitude of 200 meters above sea level. Landowners in the Lammermuir Hills of southeastern Scotland grew crops at 425 meters above sea level, during a golden age of Scottish history when interclan war­fare was virtually unheard of. A burst of cathedral building spread across Medieval Europe in the twelfth century. Chartres Cathedral, built in a mere quarter-century after 1195, is a miracle in glass and stone, where ten thousand worshipers from the surrounding country­side once gathered on festival days to pour out their love for God. Chartres and its contemporaries, were celebrations of the bounty of the soil, of generations of prosperity.

These were the climatically benign centuries when the Norse colo­nized Greenland and voyaged west to North America, William the Conqueror landed in Britain and imposed Norman rule, and Inca civilization rose to prominence in the high Andes. Warmer tempera­tures and higher sea levels affected New Zealand and the southwest Pacific, perhaps stimulating widespread Polynesian voyaging. It may be no coincidence that canoe travelers from the Society Islands set­tled New Zealand's North Island during this period, although the ex­act date of first settlement is unknown.

But the climate became more erratic during the thirteenth century. Alpine glaciers began to advance, and seasonal temperature changes became more extreme. As Arctic regions cooled, the thermal con­trast between the Greenland‑Iceland region and middle Atlantic lati­tudes steepened, causing greater storminess. Great westerly gales conspired with the prevailing high sea levels to cause vast destruc­tion. Powerful wind storms and surging sea floods inundated low-­lying North Sea coasts, drowning hundreds of thousands of people in some of the worst weather disasters ever recorded. The floods of 1240 and 1362 saw over sixty parishes in southern Denmark's dio­cese of Slesvig "swallowed by the salt sea." To add to the difficulties, tidal ranges increased after 1300, reaching a peak in 1400.

The Little Ice Age had begun.


The colder conditions of the Little Ice Age were not confined to Europe and North America. The world was on average one or two degrees Celsius cooler than it is today (during the late Ice Age it was six-to-nine degrees cooler). Precisely dated stalagmites from Cold Air Cave as far away as northern South Africa provide evidence of cooler temperatures during the Little Ice Age. Glaciers advanced, tree lines fell, and seas cooled.

The twelve-kilometer Franz Josef Glacier in New Zealand's Southern Alps once reminded me forcibly how much glaciers moved durin­g minor climatic shifts like the Little Ice Age. I walked up to the glacier face, which thrusts down a deep valley backed by mountains that rise to the precipitous heights of Mount Tasman, 3,494 meters above sea level. The path wound through the barren valley floor and across fast-running streams fed by the melting glacier, native rain fores­t rising on either side. Changes in the vegetation on the valley walls marked the limits the ice had reached in recent centuries. We wended our way between massive blocks of hard rock polished into humps by the abrasive debris collected by the ice as it advanced and retreated along the valley. The slowly retreating glacier front glistened in the hot sun, a shadow of its former self even a century before. Franz Josef is a glacier on the move.

Eight centuries ago, Franz Josef was a mere pocket of ice on a frozen snowfield. Then the Little Ice Age began, and the glacier thrust into the valley below, smashing into the great forests that flour­ished there and coming within three kilometers of the Pacific. Today signs mark its retreat. Between about 1850 and 1893, the ice retreated rapidly as the Little Ice Age ended. The twentieth century has seen advances and retreats, with a cumulative fall back of about one kilometer from its front between 1871 and 1946. The occasional adva­nces in this century, a few hundred meters over two or three years, are temporary interruptions in a steady retreat up the valley that will be reversed only by another oscillation in global climate.

The Little Ice Age was nowhere near as severe as the thousand­-year‑long Younger Dryas that triggered agriculture ten thousand years ago. At its height, between A.D. 1550 and 1700, mean tempera­tures were 1.2--1.4 degrees Celsius below those of the Medieval Warm Period.

 What caused the Little Ice Age? Scientists are still deeply divided over that question. All agree that it was an episode of profound im­portance to modern understanding of climatic change, for it unfolded during six hundred years of recent history when humanly caused global warming was not a potential factor.

    As we have seen, the complex circulation patterns and interactions of the atmosphere and ocean area major driving force in short‑term climatic change. Could a massive influx of freshwater into northern waters from thawing glaciers and sea ice have turned off the "switch" that drives the North Atlantic Current and the Great Ocean Conveyor Belt in the deep ocean, as scientists like Wallace Broecker theorize? Or did variations in ground-level solar intensity cause the Little Ice Age? The scientific jury is still out. A decrease of 1 percent in the radiation output of the sun would be enough to lower global average temperatures by one or two degrees Celsius, causing continental sea ice and snow cover to expand, with resulting changes in atmosphere and ocean circulation patterns. For instance, sunspot activity was exceptionally low from 1715 to 1845, one of the coldest spells of the Little Ice Age. Could the sun's brightness and energy output have di­minished enough to cause a global temperature drop? Unfortunately, no one knows exactly how solar variability affects climatic change.

The Little Ice Age witnessed remarkable volcanic activity: an aver­age of five major eruptions per century that equaled the intensity of the Krakatoa eruption in 1883. Such episodes inject massive quanti­ties of microparticles and gases into the atmosphere, causing massive dust veils that dim the moon and sun and affect global temperatures. The ash content of a central Greenland ice core shows that the years of the Medieval Warm Period between 1100 to 1250 were quiet vol­canically. Between 1250 and 1500 and between 1550 and 1700, how­ever, there were many eruptions, including a massive one in 1600 at an unknown location. Many scientists are sure that volcanic activity produced brief climatic extremes during the five cold centuries. They know the eruption of Mount Pinatubo in the Philippines in 1991 low­ered the world's average temperature by about one degree for two years. They also point to 1816, "the year without a summer," as proof of the power of volcanic activity.

Between April and June 1815, Mount Tambora, a volcano on the island of Sumbawa in Indonesia, erupted massively. The explosion was heard in Sumatra, sixteen hundred kilometers away. Only twenty-six of the island's twelve thousand people survived. Ash clouds fell in Java, over five hundred kilometers away. Tambora was the largest volcanic eruption in modern times. The exploding volcano pumped into the atmosphere ten times the amount of ash produced by the notorious Krakatoa. Huge quantities of dust and sul­phur dioxide produced a reverse greenhouse effect, forming in effect a sunscreen around the earth. Europe and North America shivered in 1816. Glaciers in the European Alps advanced vigorously. Snow fell in New England in June and July, crops failed throughout Europe, and famine was widespread. The raw summer weather caused the vacationing English poet Percy Bysshe Shelley and his wife Mary to stay indoors during their holiday on the shores of Lake Geneva. They entertained their friends by telling horror stories. Mary dazzled her audience with one called Frankenstein, about a monster that perishes with its creator in the frozen arctic.

Perhaps a dimmer sun and intense volcanic activity were players in the Little Ice Age equation. Whatever its cause, the five centuries of cooler weather brought profound changes in European history.

In about A.D. 982, the Norseman Eirik Thorvaldsson the Red sailed west from Iceland to explore the mysterious lands that sometimes ap­peared on the far horizon when the winds blew from the north. Three years later he and his men returned with stories of a fertile uninhabited land where fish were plentiful and the grazing grass lush and green. Eirik named it the Green Land, "for he said that people would be much more tempted to go there if it had an attractive name."

Eirik persuaded twenty-five shiploads of settlers to sail for Green­land in 986. They founded the village of Brattahlid in the southwest and a "Western Settlement" at Gotthab some 650 kilometers to the north. Life was never easy. The restless and adventurous Greenlanders occupied lowland areas around the inner shores of fjords, where they could pasture their stock and perhaps attempt to grow corn. All animals lived inside during the long winters, when the settlers lived off dried meat, fish, and stored dairy products. Their staple diet was seal meat, collected by the ton when harp seals migrated northward along the west coast in May and June.

The Greenland Norse always lived on the edge. Their lives de­pended on making full use of seasonal migrations of harp seal and caribou to obtain winter meat supplies. During the summers, the settlers mounted polar bear and walrus hunting expeditions to Nordsetur, the "northern coast" around Disko Bay, more than eight hundred kilometers north of the main western settlements. Bearskins and walrus tusks were the only trade goods of interest to the outside world. The Greenland Norse paid their annual church tithe to distant Norway in walrus tusks. Sometimes the tithe was more than four hundred tusks, far more than they could collect around their own settlements.

The colonists were expert seamen who explored every fjord and bay of western Greenland. Very early on, bold young men ventured far north toward the arctic ice and across the foggy and hazardous Davis Strait to the Ubygdir, the "unpeopled tracts," new lands beyond the western horizon.

During the 990s, Leif Eiriksson, son of Eirik the Red, sailed across to Baffinland, then southward in front of a northeast wind along the Labrador Coast to Newfoundland and the mouth of the Saint Lawrence River. Eiriksson wintered over in a wooded land he named Vinland, after the wild grapes that grew there, perhaps in Passamaquoddy Bay in northern Maine. The following year he and his thirty‑five men returned safely to Greenland with a full load of timber.

The Norse never settled permanently in North America. They could survive on harsh Greenland coasts as long as the climate was relatively predictable, but they lacked the numbers and resources to expand and maintain pioneer settlements far to the west, where they had to compete with large indigenous populations and sail on ice-­strewn, hazardous seas. Nor were there strong motives for coloniza­tion-- such as religious persecution at home, or promises of gold and fertile land to attract greedy adventurers. So the Norse voyaged west­ward sporadically in search of timber, which was in short supply in Greenland.

The Greenlanders depended on the constancy of temperature swings and ice conditions from one season to the next. Even small perturbations greatly affected the abundance of food. During a cycle of slightly cooler years between 1954 and 1974, for instance, summer harp seal catches in the Gotthab area of western Greenland declined sharply. Further north, the Kapisigdlit station, situated in a sheltered fjord, saw the percentage of harp seals in the annual catch fall from 30 percent to a mere 4 percent. If even this minor cooling caused such a profound drop, we can only imagine the consequences of a more prolonged and severe cold snap on a population living close to the edge. At the same time the harp seal catch was failing, longer win­ters would have required that domesticated animals be kept indoors longer in years when a shorter growing season had yielded much less hay. Colder and longer winters could also have deepened the snow cover, leading, in turn, to a dramatic reduction, even the temporary extinction, of caribou in parts of southwestern Greenland.

With their food base thus contracted, Norse fortunes declined rapidly. Malnutrition and premature deaths plagued even well-established settlements. Isolated communities became more vulnerable to attack from hostile Inuit groups. Meanwhile, the Inuit flour­ished in the cooler conditions, for they had adapted to Greenland's harsh and unpredictable environment for many thousands of years. They wore layered, tailored skin clothing that allowed them to hunt in subzero temperatures. Light Inuit skin boats and kayaks were ideal for operating in ice‑strewn waters. Their harpoon technology, fash­ioned from bone and ivory, was among the most sophisticated in the world, so they could hunt cold-loving ring seal and fish through the ice in the depths of winter. Unlike the Norse, they were not solely de­pendent on the summer‑migrating harp seal.

Unable to hunt sea mammals in winter, and apparently reluctant to change their lifeway, the Norse succumbed to climatic stress. By 1350 they had abandoned the Gotthab settlement, perhaps after an attack by local Inuit. By 1500 the larger eastern settlement was also empty. When the ice spread farther south and endangered the most direct sailing route to the Green Land, even the most tenuous links evaporated as the bitter cold of the Little Ice Age caused major economic disruption throughout Europe. 

Like the Greenlanders, Icelanders were at the mercy of sudden climatic changes. They subsisted mainly on fish and cattle, so land and sea temperatures and hay harvest yields were of vital concern. Hay grass is highly sensitive to air temperatures. Colder-than-average winters with intense frosts and deep snow cover can retard growth or even kill off the grass crop before summer. The soil may stay frozen until late spring, when a quick thaw floods the ground and kills the new grass all at once. In the exceptionally cold 1967 growing season, for example, hay production fell by one-fifth, with yields of 870 kilograms less per hectare than normal. Experts have calculated that a tempera­ture deviation of one degree Celsius from the 1901-1930 norm of 3.2 degrees Celsius reduces the carrying capacity of the land by 30 percent. Despite modern farming practices, the Icelandic government still has to purchase and transport hay in cold years, at enormous expense.

Sea temperatures around Greenland and Iceland dropped precipi­tously for much of the time between 1600 and 1830, decimating cod populations, another staple of the Icelandic diet. Cod flourish in wa­ters between two and thirteen degrees Celsius, but their kidneys do not function in colder water. Even a minor shift in polar water causes the fish to follow warmth. The Norse had subsisted off cod during the heyday of their settlements in Greenland, but there were no stocks off Greenland during the Little Ice Age. Cod disappeared completely from the Norwegian Sea during the seventeenth century as polar water spread southward.

Iceland has exported fish since the fourteenth century, although the size of cargoes was limited until the introduction of decked ships in 1890. But the industry has always been at the mercy of cooler sea temperatures. Even with modern industrial-scale fishing, herring and cod catches rise and fall with water temperatures. One of the major reasons for Iceland's bitter confrontations with Britain in the 1960s over fishing rights was the deterioration of fish stocks around Iceland as a result of falling sea temperatures. Iceland's dependence on cod and herring has made it vulnerable to sudden climatic change and resulted in firm, even extreme, political stands on fishing rights.

Until the onset of the Little Ice Age, the Icelanders also grew a hardy strain of barley in the north, south, and southeast of their homeland. However, the farmers had abandoned barley cultivation in the north by the end of the twelfth century. By the fifteenth century, no one grew cereal crops. Despite occasional experiments, barley did not return for eight centuries.

The Little Ice Age caused great suffering in Iceland from the sev­enteenth to the nineteenth century, a period during which mountain glaciers advanced, hay crops fell sharply, and thousands of cattle died of hunger and cold. In 1757 the sheriff of Salasysla in the northwest reported that "just in this year 21 cows and bulls, 1,292 sheep, 3,209 young lambs, and 151 horses have died in this one district. Forty-five people have died of hunger and wretchedness, and 15 dwellings have been deserted." He also reported poor fishing and noted that it "will be a pure miracle if a third of the population does not die of hunger." The Icelanders fished from open boats. Even when they could launch their vessels into the ice-strewn water, they could not venture far from land. In the brutally cold years from 1750 to 1758, many fisherfolk moved inland and descended on hungry farming rel­atives. Nearly seventeen thousand people out of an island population of fifty thousand souls perished of hunger and associated ailments.

The start of the Little Ice Age had an immediate effect on European agriculture. Northern European vineyards went out of production between 1300 and 1310. Between 1313 and 1317, a series of exception­ally wet and unusually cold summers caused widespread crop failures and famine that killed thousands of people. There were outbreaks of cannibalism, and entire villages were abandoned or their populations decimated. The wet, cool summers and disastrous harvests under­mined the viability of many small farming villages. Thirty years later the Black Death savaged Europe. Many of the hardest hit were those weakened by earlier famines.

     By the beginning of the fifteenth century, most northern European farmers had abandoned wheat cultivation altogether. Wheat was a tricky crop at the best of times in the north, requiring constant tilling, frequent and careful manuring, and meticulous rotation from field to field. English visitors to a Danish wedding in 1406 commented on the widely sodden ground and lack of wheat fields. In Norway, where the cold weather and plague had reduced the population by two-thirds over the preceding century, upland farms lay deserted. By the 1430s many district tax yields had fallen to one-quarter of their level in 1300. Many poor families ate rye bread, which, a French doctor wrote in 1702, "is not as nourishing as wheat and loosens the bowels a little." However, the bread crops never created abundance. Farmers ate beans and peas and made flour from buckwheat or chestnuts. Cattle were as important as cereal crops, for they provided meat and milk as well as manure. But the farmers were caught in a vicious circle, for they needed animals to draw plows and to fertilize the soil. Their beasts in turn required more grazing land at the expense of cul­tivated fields. A fourteenth‑century almanac adjured the farmer to "multiply his livestock for it is this which will give the land the ma­nure that produces rich harvests." Nor did crops like barley, oats, and rye produce higher crop yields. The plants choked one another. From the fourteenth to the eighteenth century, Europe's peasants subsisted on coarse soups and gruels, as they had in prehistoric times.

The 1430s saw long spells of severe winter weather interspersed with very dry, hot summers and exceptionally wet springs and falls that caused havoc from England to the Alps. The Scottish Highlands erupted in warfare between hitherto peaceful clans. The severe winters reduced many Highlanders to making bread from tree bark. The murder of King James I, while hunting near Perth in 1436, was a direct result of famine-related social disorder, an event that caused the capital to be moved to the fortress at Edinburgh.

    By 1500 European summers were about seven degrees Celsius cooler than they had been during the Medieval Warm Period. The growing season in England was shortened by about three weeks, and by as much as five by the seventeenth century. At the same time, the ground grew wetter. Marshes spread, and rivers flowed more strongly, making agriculture even more of a struggle. In northern Norway, the highest altitude level at which farming was possible fell by at least 150 meters between 1300 and 1600. Fortunately, the warm Atlantic currents had kept the Icelandic and Norwegian fisheries op­erating when agriculture was in decline. During the early 1500s the climate warmed up somewhat, giving momentary relief. Wheat yields and land values increased slightly, only to fall again as the Little Ice Age reached its climax between 1550 and 1700. This time, temperatures in northern seas dropped sharply and cod catches fell dramatically, adding to the distress.

Some of the greatest suffering came in the shadow of the Alps. In June 1644, a procession of three hundred people led by the bishop of Geneva, Charles de Sales, made its way high in the Alps to "the place called Les Bois above the village where hangs, threatening it with total ruin, a great and terrible glacier come down from the top of the mountain." The villagers had good reason to worry, for the Les Bois glacier was advancing "by over a musket shot [120 meters] every day, even in the month of August." The bishop duly blessed the glacier and repeated his invocations at a whole ring of ice sheets, which hemmed in seven small villages. It was as well that his blessings worked and the glaciers retreated, for the Les Bois glacier had blocked the valley of Chamonix itself and threatened to transform it into a lake. A quarter-century later, the ice sheets had retreated, but "the land they occupied [was] so barren and burned that neither grass nor anything else has grown there."

Still, the worthy bishop's efforts had little immediate effect. Between 1640 and 1650, a decade with cool and extremely wet summers, glaciers throughout the European Alps advanced farther than at any time since the Ice Age. In desperation, the people again prayed for mercy. By September 1653, the Aletsch glacier threatened so much farmland that the local people asked the Jesuits for assis­tance. Fathers Charpentier and Thomas preached reassurance to the community' for a week. Then a solemn procession walked for four hours, bareheaded in the rain, to the "snake-shaped" glacier. The supplicants heard mass and a short sermon, before the priests sprinkled the front of the glacier with holy water in the name of Saint Ignatius and recited "the most important exorcisms." "On that very spot just in front of the glacier, they set up a column bearing his effigy: it looked like an image of Jupiter, ordering an armistice not just to his routed troops, but to the hungry glacier itself."

We are told that Saint Ignatius stopped the glacier in its tracks, but rapidly advancing Alpine ice sheets continued to threaten farming communities in the foothills. In the eastern Alps the expanding Vernagt glacier repeatedly dammed river valleys and formed lakes behind rubble barriers that broke repeatedly, flooding everything downstream. At Christmas 1677, one village burned a vagrant suspected of practicing magic to block the valley. Hundreds of people died in unexpected, catastrophic floods. Farming populations fell sharply as people fled the encroaching ice. The hovering glaciers in the Chamonix area brought bone-chilling cold, perennial frosts, and "such strong winds that they sometimes carry away part of the hay and grass after it has been cut."

The parish records of tiny mountain communities high in the Alps chronicle great suffering during the Little Ice Age. The French historian Le Roy Ladurie has likened the fluctuations of Alpine glaciers to the endless cycles of ocean tides. After centuries of "low water" during the Middle Ages, the ice sheets were high in the mountains. Then, around A.D. 1300, the tide began to rise and the glaciers spread downslope. A glacial "high tide" brought the ice deep into foothill valleys between 1590 and 1850. The greatest thrusts occurred in the seventeenth century and again in 1818--1820 and 1850--1855, scarring villages and decimating Alpine pastures. By 1860 the tide had turned and a great retreat began. By 1900 many glaciers had re­ceded more than two kilometers deeper into the mountains in just forty years. In the 1990s the tide is still out, as we live through some of the warmest weather in six centuries.

A few contemporary weather records serve to show how extreme conditions were. With the southward spread of arctic water into northern seas, ice occasionally blocked the Denmark Strait between Iceland and [Greenland] and in 1695 it even mantled the entire Norwegian coast. Winter temperatures in England were up to one and a half degrees Celsius lower than the average for 1900-1950. In 1608 sev­eral meters of ice covered the Thames River. The exceptionally cold winter of 1684 froze the ground in parts of southern England to a depth of over a meter, while ice formed a five-kilometer belt along the English Channel coast. The length of winter frosts was much longer and the depths of snow cover much higher than in the twentieth century -- up to 112 days at Zurich, Switzerland, in 1684. Interestingly, the most destructive weather often came in March, which in the 1880s was as much as three degrees Celsius colder than the twentieth-century average. This had serious consequences for local farmers, who ran out of hay and had to feed their cattle on pine branches and straw. They slaughtered many of their beasts while also enduring poor harvests, caused in part by a parasite that was active under snow cover and attacked growing corn.

Not that it was always exceptionally cold. There were some very mild winters during the height of the Little Ice Age, often soon after extremely cold years. Europe enjoyed tremendous variation during these centuries: The standard deviation of winter temperatures in England and the Netherlands was about 40 percent to 50 percent greater during the severest centuries of the Little Ice Age than during the early twentieth century, when westerly winds from the Atlantic Ocean dominated the weather pattern. There were occasional sum­mer heat waves, too, notably in late June and July 1665, when the plague decimated London. The following year saw the twelfth­warmest summer temperatures in the previous 320 years and the Great Fire of London.

Despite their hardships, Londoners made the most of cold winters.  They skated and partied on frozen rivers and used them as roads. On January 24, 1684, the diarist John Evelyn wrote of "frost . . . more & more severe, the Thames before London was planted with bothes [booths] in formal streets, as in a Citty . . . . It was a severe judgement on the Land: the trees not onely splitting as if lightning-strock, but Men & Catell perishing in divers places, and the very seas so locked up with yce, that no vessells could stirr out, or come in." The still, cold air trapped ascending coal smoke, causing serious air pollution. The "fuliginous steame of the Sea Coal" prevented one from seeing across the street and filled Londoners' lungs with "grosse particles." Evelyn heard stories of extremely cold weather as far south as Spain "& the most southern tracts."

As Londoners partied, the Scots suffered grievously. Up to one­third of the upland population died between 1693 and 1700, during the years immediately preceding the union with England in 1707. The harsh climate may have helped make union inevitable. A contempo­rary official wrote: 

During these disastrous years the crops were blighted by easterly "haars" or mists, by sunless drenching summers, by storms, and by early bitter frosts and deep snow in autumn. For seven years the calamitous weather continued, the corn [i.e., grain] barely ripen­ing .... Even in the months of January and February, in some districts many of the starving people were still trying to reap the remains of their ruined crops of oats, blighted by the frosts, and perished from weakness, cold, and hunger. 

Throughout northern and western Europe, the coldest years of the 1690s, the years around 1740, and 1816-1819 were periods of constant famine. The harvest of 1693 was the worst in western Europe since the Middle Ages. France became a "great desolate hospital without provisions." Crop failures resulting from unusually heavy rainfall, part of worldwide climatic anomalies perhaps connected to the great ENSO episode in the late 1780s and early 1790s, contributed to the unrest that led to the French Revolution.

Unexpected salvation came from South America. Before the dis­covery of the Americas, European farmers depended primarily on cereals like barley, wheat, oats, and rye. Bread and various porridges made from these grasses, like Scottish oatmeal, formed the staple diet of millions of peasants. Except for a few roots eaten as side dishes - carrots, parsnips, and turnips - they relied almost exclusively on cereals. Crops like barley and wheat, which grow on long stalks high above the ground, are vulnerable to strong winds, hail, and excessive rainfall. Birds and insects eat the ripening grain. Cereal agriculture could be extremely productive in warmer, Mediterranean climates, but in northern Europe extreme weather and the resulting crop failures brought severe cereal shortages. The agriculture that had flour­ished during the Medieval Warm Period was ill suited to the Little Ice Age.

The solution to endemic famine came in the form of an ugly tuber first domesticated high in the Peruvian Andes.

The highland Andean Indians grew at least three hundred varieties of potatoes. Like maize and tobacco, potatoes were carried to Europe by Spanish conquistadors. Europeans spurned the new root crop at first. Folktales alleged that the misshapen potato caused leprosy. Some Russian Orthodox priests proclaimed potato eating a sin and named it the "devil's plant." Prussian servants threatened to change masters if fed potatoes. For two centuries the potato was little more than a curiosity, grown in some monastery gardens and by some gourmets as a novelty food. Cultural resistance to the potato was so strong that farmers would willingly endure repeated famine rather than change their diet.

Once introduced, however, potatoes flourished in northern Europe, an environment as cool and damp as their Andean homeland. Ireland was the first country to grow the potato on a large scale. Legend has it that the tubers arrived aboard shipwrecks from the Spanish Armada in 1588, but they did not become a staple until the late sev­enteenth century. Irish farmers discovered that a piece of land that would feed one person on wheat could feed two on potatoes. The population of Ireland almost tripled as a result, from 3.2 million in 1754 to 8.2 million in 1845. Had the Irish followed the Native American practice of diversifying their potato strains, they might have avoided the disastrous effects of the potato blight that caused the dreadful famines of the mid‑nineteenth century.

From Ireland, potato agriculture spread eastward across Britain and into the Low Countries. The great economist Adam Smith drew attention to the potato in his Wealth of Nations, published in 1776, and predicted it would feed large numbers of working people, making men stronger and women more beautiful. By the late eighteenth century, Frederick the Great of Prussia was forcing his subjects to grow potatoes or starve. Other monarchs did the same. Their advisers had learned that potatoes yielded more nutrition for less work per hectare than any grain crop, over a growing season of three to four months as opposed to almost double that for cereals. Potatoes grew in a wider variety of soils, needed less attention after planting, and, unlike oats and wheat, did not require lengthy grinding and processing. They could be stored for up to a year and made into bread or all manner of different dishes.

Once adopted, the new crop rapidly became a staple. Between 1693 and 1791, grain consumption in Flanders alone fell from 758 grams per person per day to 475 grams as potatoes replaced about 40 percent of cereal consumption. Nutritional diseases declined throughout Europe. By the 1830s northern Europe had become a major economic force, partly because the potato had reduced the famine cycles so typical of the Little Ice Age. In France, for example, there were 111 famines between 1371 and 1791, sixteen of them in the eighteenth century alone. The potato effectively eliminated this cata­strophic cycle. The productivity and reliability of potato farming helped increase Europe's population and freed more workers for nonagricultural employment --such as manning the factories of the Industrial Revolution.

The cold centuries ended in the 1850s, as the Industrial Revolution was at its height. The world entered a new era of warmer tempera­tures and less extreme climatic swings, apparently triggered by entirely natural causes. (Some experts do wonder whether the higher levels of carbon dioxide released into the atmosphere by the growing forces of the Industrial Revolution contributed to the warm-up.) The warming has continued to this day, interrupted by occasional colder episodes. The three severe winters of 1939-1942 frustrated Adolf Hitler in France and Russia. Between 1940 and 1975, the world's climate cooled very slightly despite increased carbon dioxide levels, prompting talk of an imminent Ice Age. Since the 1970s the warming has continued.

Climatologists report that 1997 was the warmest year in the twentieth century, with 1998 promising to be as warm if not warmer. How much of this warmth is due to the burning of fossil fuels and other human activities is a matter of debate. Perhaps another Little Ice Age is less likely now than it would have been had not the burning of fossil fuels increased so dramatically during the twentieth century. But we would be foolish to assume that another Little Ice Age is an impossibility.

Five centuries of cold caused subsistence crises in Europe. Today the same landscape produces large food surpluses on an industrial scale. But elsewhere people still starve. Now Africa suffers from hunger, caused by drought, social disorder, war, and massive cultural changes.


The following section on scapegoating is from Fagan's The Little Ice Age (Basic Books, 2000):

 “As climatic conditions deteriorated, a lethal mix of misfortunes descended on a growing European population.  Crops failed and cattle perished by diseases caused by abnormal weather.  Famine followed famine bringing epidemics in their train, bread riots and general disorder brought fear and distrust.  Witchcraft accusations soared, as people accused their neighbors of fabricating bad weather….  Sixty-three women were burned to death as witches in the small town of Wisensteig in Germany in 1563 at a time of intense debate over the authority of God over the weather.  Witch panics erupted periodically after the 1560s. Between 1580 and 1620, more than 1,000 people were burned to death for witchcraft in the Bern region alone.  Witchcraft accusations reached a height in England and France in the severe weather years of 1587 and 1588.  Almost invariably, a frenzy of prosecutions coincided with the coldest and most difficult years of the Little Ice Age, when people demanded the eradication of the witches they held responsible for their misfortunes.  As scientists began to seek natural explanations for climatic phenomena, witchcraft receded slowly into the background.”