The Little Ice Age: How Climate Made History 1300-1850
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The great French historian Emmanuel Le Roy Ladurie once remarked that there were two kinds of historians: parachutists and truffle hunters. The parachutist observes the past from afar, slowly floating down to earth, while the truffle hunter, fascinated by treasures in the soil, keeps a nose close to the ground. Some of us are by temperament parachutists in everyday life. Many others are truffle hunters, with fine minds for detail. We bring this baggage with us when we study the past. I burden under the impedimenta of a parachutist in this book, which glosses over many passionate historical controversies. In writing it, I have relied on the advice of many colleagues, who are far more learned in the business of history than I. It is impossible to acknowledge everyone's help here. I hope that those not mentioned below will accept the homage of a neophyte historical parachutist.
The Little Ice Age has involved navigating a highly complex, diffuse literature in many disciplines and interviews with scholars with many specialties. I never expected to explore the esoteric byways of Hudson's Bay Company history, European oil paintings, the North Atlantic Oscillation, and Dutch sea defenses, but the journey has been exceptionally rewarding. My special thanks to my historian colleague at Santa Barbara, Sears McGhee, who jump-started me into the complex literature of European history and gave me much sage advice. Professor Theodore Rabb kindly read a rough draft of the hook and made invaluable suggestions. I am grateful to David Anderson, William Calvin, Jan De Vries, Peter Gruntfuttock, John Hurst, Phil Jones, Terry Jones, William Chester Jordan, George Michaels, Tom Osborn, Christian Pfister, Prudence Rice, Chris Scarre, Alexa Schloe, Andrew Selkirk, Crispen Tickell, William Truckhouse, Richard Unger, Charlie Ward, and many others for advice, en couragement, and references. As always, Steve Cook and Shelly Lowenkopf were pillars of encouragement when the going got rough and I found myself batting my head against literary walls. Our weekly coffee drinking is a true learning experience.
My greatest debt is to my editor, William Frucht of Basic Books. He has been a wonderful sounding board, ruthless critic, and vital catalyst for what has turned out to be an engrossing and extremely demanding project. I am in awe of his perceptions and superb editorial skills. Jack Scott designed and drew the illustrations with his usual skill. My agent Susan Rabiner has encouraged me at every turn. And, finally, a word of thanks to my family for their patience, and to our cats, who have, as usual, sat on my keyboard with unerring accuracy at just the wrong moments. I fervently hope this is a sign of approval, even if flicking tails suggest otherwise.
All measurements in this book are given in metric units. A meter is slightly longer than a yard, and sixteen kilometers is roughly ten miles. Water freezes at 0' Centigrade and boils at 100`C. An ideal temperature to be outdoors is about 25'C (77° Fahrenheit).
Place names are spelled according to the most common usages. Archaeological sites and historical places are spelled as they appear most commonly in the sources used to write this book.
Nonmeteorologists and nonsailors should note that wind directions are described, following common maritime convention, by the direction they are coming from. A westerly wind blows from the west. Ocean currents, however, are described by the direction they are flowing toward. Thus, a westerly wind and a westerly current flow in opposite directions.
WARMTH AND ITS AFTERMATH
-Geoffrey Chaucer, Canterbury Tales
And what a wonder! Some knights who were sitting on a magnificently outfitted horse gave the horse and their weapons away for cheap wine; and they did so because they were so terribly hungry.
A German chronicler of 1315
Major historical and climatic events, 950 to 1500
Anonymous, Hafgerdinga Lay
("The Lay of the Breakers')
he fog lies close to the oily, heaving water, swirling gently as a bitterly cold air wafts in from the north. You sit gazing at a featureless world, sails slatting helplessly. Water drips from the rigging. No horizon, no boundary between sea and sky: only the gray-shrouded bow points the way ahead. The compass tells you the boat is still pointing west, barely moving through the icy chill. This fog can hug the water for days, hiding icebergs and the signs of rapidly forming pack ice. Or a few hours later, a cold northeaster can fill in and sweep away the murk, blowing out of a brilliantly blue sky. Then the horizon is as hard as a salt-encrusted knife, the sea a deep blue frothing with white caps. Running easily under reduced sail, you sight snow-clad peaks far on the western horizon a halfday's run ahead-if the wind holds. As land approaches, the peaks cloud over, the wind drops, small ice floes dot the now-calm ocean. The wise mariner heaves to and waits for clearer weather and a breeze, lest ice block the way and crush the ship to matchwood.
Icebergs move haphazardly across the northern seas. Pack ice floes undulate in broken rows in the endless ocean swell. Far to the north, a ribbon of gray-white light shimmers above the horizon, the ice-blink of solid pack ice, the frontier of the Arctic world. To sail near the pack is to skirt the barrier between a familiar universe and oblivion. A brilliant clarity of land and sky fills you with keen awareness, with fear of the unknown.
For as long as Europeans can remember, the frozen bastions of the north have hovered on the margins of their world, a fearsome, unknown realm nurturing fantastic tales of terrible beasts and grotesque landscapes. The boreal oceans were a source of piercing winds, vicious storms and unimaginably cold winters with the ability to kill. At first, only a few Irish monks and the hardy Norse dared sail to the fringes of the ice. King Harald Hardrade of Norway and England is said to have explored "the expanse of the Northern Ocean" with a fleet of ships in about A.D. 1040, "beyond the limits of land" to a point so far north that he reached pack ice up to three meters thick. He wrote: "There lay before our eyes at length the darksome bounds of a failing world."' But by then, his fellow Norse had already ventured far over northern seas, to Iceland, Greenland and beyond. They had done so during some of the warmest summers of the previous 8,000 years.
I have sailed but rarely in the far north, but the experience, the sheer unpredictability of the weather, I find frightening. In the morning, your boat courses along under full sail in a moderate sea with unlimited visibility. You take off your foul-weather gear and bask in the bright sun with, perhaps, only one sweater on. By noon, the sky is gray, the wind up to 25 knots and rising, a line of dense fog to windward. The freshening breeze cuts to the skin and you huddle in your windproof foulies. By dusk you are hove-to, storm jib aback, main with three reefs, rising and falling to a howling gale. You lie in the darkening warmth belowdecks, listening to the endless shrieking of the southwester in the rigging, poised for disaster, vainly waiting for the lesser notes of a dying storm. A day later, no trace remains of the previous night's gale, but the still, gray water seems colder, about to ice over.
Only the toughest amateur sailors venture into Arctic waters in small craft, and then only when equipped with all the electronic wizardry of the industrial age. They rely on weather faxes, satellite images of ice condi tions, and constant radio forecasts. Even then, constantly changing ice conditions around Iceland and Greenland, and in the Davis Strait and along the Labrador coast, can alter your voyage plans in hours or cause you to spend days at sea searching for ice-free waters. In 1991, for example, ice along the Labrador coast was the worst of the twentieth century, making coastal voyages to the north in small craft impossible. Voyaging in the north depends on ice conditions and, when they are severe, small boat skippers stay on land. Electronics can tell you where you are and provide almost embarrassing amounts of information about what lies ahead and around you. But they are no substitute for sea sense, an intimate knowledge of the moody northern seas acquired over years of ocean sailing in small boats, which you encounter from time to time in truly great mariners, especially those who navigate close to the ocean.
The Norse had such a sense. They kept their sailing lore to themselves and passed their learning from family to family, father to son, from one generation to the next. Their
maritime knowledge was never written down but memorized and refined by constant use. Norse navigators lived in intimate association with winds and waves, watching sea and sky, sighting high glaciers from afar by the characteristic ice-blink that reflects from them, predicting ice conditions from years of experience navigating near the pack. Every Norse skipper learned the currents that set ships off course or carried them on their way, the seasonal migrations of birds and sea mammals, the signs from sea and sky of impending bad weather, fog, or ice. Their bodies moved with swell and wind waves, detecting seemingly insignificant changes through their feet. The Norse were tough, hard-nosed seamen who combined bold opportunism with utterly realistic caution, a constant search for new trading opportunities with an abiding curiosity about what lay over the horizon. Always their curiosity was tempered with careful observations of currents, wind patterns, and icefree passages that were preserved for generations as family secrets.
The Norse had enough to eat far from land. Their ancestors had learned centuries before how to catch cod in enormous numbers from open boats. They gutted and split the fish, then hung them by the thousands to dry in the frosty northern air until they lost most of their weight and became easily stored, woodlike planks. Cod became the Norse hardtack, broken off and chewed calmly in the roughest seas. It was no coinci dence Norse voyagers passed from Norway to Iceland, Greenland and North America, along the range of the Atlantic cod. Cod and the Norse were inextricably entwined.
The explorations of the Norse, otherwise known as Vikings or "Northmen," were a product of overpopulation, short growing seasons, and meager soils in remote Scandinavian fjords. Each summer, young "rowmen" left in their long ships in search of plunder, trading opportunities, and adventure. During the seventh century, they crossed the stormy North Sea with impressive confidence, raided towns and villages in eastern Britain, ransacked isolated Christian settlements, and returned home each winter laden with booty. Gradually, they expanded the tentacles of Norse contacts and trade over huge areas of the north. Norsemen also traveled far east, down the Vistula, Dnieper, and Volga rivers to the Black and Caspian seas, besieged Constantinople more than once and founded cities from Kiev to Dublin.
The tempo of their activity picked up after 800. More raiding led, inevitably, to permanent overseas settlements, like the Danish Viking camp at the mouth of the Seine in northern France, where a great army repeatedly looted defenseless cities. Danish attackers captured Rouen and Nantes and penetrated as far south as the Balearic Islands, Provence, and Tuscany. Marauding Danes invaded England in 851 and overran much of the eastern part of the country. By 866, much of England was under the Danelaw. Meanwhile, the Norwegian Vikings occupied the Orkney and Shetland Islands, then the Hebrides off northwestern Scotland. By 874, Norse colonists had taken advantage of favorable ice conditions in northern seas and settled permanently in Iceland, at the threshold of the Arctic.
The heyday of the Norse, which lasted roughly from A.D. 800 to about 1200, was not only a byproduct of such social factors as technology, overpopulation and opportunism. Their great conquests and explorations took place during a period of unusually mild and stable weather in northern Europe called the Medieval Warm Period-some of the warmest four centuries of the previous 8,000 years. The warmer conditions affected much of Europe and parts of North America, but just how global a phenomenon the Warm Period was is a matter for debate. The historical consequences of the warmer centuries were momentous in the north. Be tween 800 and 1200, warmer air and sea surface temperatures led to less pack ice than in earlier and later centuries. Ice conditions between Labrador and Iceland were unusually favorable for serious voyaging.
The Norse were not the first visitors to Iceland. Irish monks, seeking peaceful refuges far from the political and social turmoil at home, had preceded them. The oceangoing prelates settled the Faeroe Islands by A.D. 700 and sailed as far north as Iceland by 790. Legend has it they followed the spring migration of wild geese to land. But these remarkable seamen were unable to (or in any case did not) maintain a permanent settlement. Norse ships arrived three-quarters of a century later, at a time when January pack ice rarely reached the island's northern coast and both winter and summer temperatures were usually higher than today.
The ocean currents and atmospheric conditions near Iceland have an important bearing on temperature and rainfall throughout northwestern Europe. Warm water from the Atlantic and cold water from the Arctic converge on Iceland's shores. A branch of the cold East Greenland current sweeps along the north and east coasts of the island. The warmer Irminger current flows along the south shore and is an arm of the North Atlantic current, which, in turn, originates in the Gulf Stream deep in the North Atlantic Ocean. Today, in average years, the January to April pack ice edge lies about 90 to 100 kilometers off the northwestern corner of Iceland. In a mild year, the edge is 200 to 240 kilometers away, whereas an exceptionally cold season can bring pack right to the north coast and even around the eastern side of the island to the southern shore. An Irish monk named Dicuil, writing in A.D. 825, recorded that his brethren living in Iceland found no ice along the south coast but encountered it about a day's sail away from the north shore, the position the pack has occupied for most of the twentieth century. In contrast, during a period of great cold between 1350 and 1380, sea ice came so close to land that Greenland polar bears came ashore.
The new colony would never have survived had not the winters been milder than in earlier centuries. Even in good years, the Icelanders scrabbled for a living from thin soils and bitterly cold seas. In bad years they courted disaster. Oddur Einersson observed in 1580 that "the Icelanders who have settled on the northern coasts are never safe from this most terrible visitor.... Sometimes it is absent from the shores of Iceland for many years at a time.... Sometimes it is scarcely to be seen for a whole decade or longer. . . . Sometimes it occurs almost every year." In a bad ice year, such as those of the 1180s or 1287, people starved, especially when several harsh winters followed one upon the next. In the extreme winter of 1695, ice blocked the entire coast in January and stayed until summer. A contemporary account tells us: "The same frosts and severe conditions came to most parts of the country; in most places sheep and horses perished in large numbers, and most people had to slaughter half their stock of cattle and sheep, both in order to save hay and for food since fishing could not be conducted because of the extensive ice cover."2 Icelandic agriculture is vulnerable to harsh winters to this day. For example, intense icing and low temperatures during the severe winter of 1967 reduced farmers' productivity by about a fifth-this in an era of improved farming methods and livestock, indoor heating, and a sophisticated transport infrastructure.
The Norse brought with them a medieval dairying economy like that at home, which they combined with seal hunting and cod fishing. Warmer summer temperatures allowed them to obtain reasonably ample hay harvests for winter fodder and also to plant barley, even near the north coast, where it was cultivated until the twelfth century. After that, farmers could never grow barley in Iceland until the early 1900s.
Sometime in the late tenth century, Eirik the Red and his father Thorvald Asvaldsson left their home in southwestern Norway "because of some killings." They sailed westward to Iceland but had to make do with farfrom-fertile land. Eirik was quarrelsome and endowed with a temper that matched his red hair. He married a well-connected Icelandic woman, there were more killings, and he was forced out to a farm on a windswept island. Even there he quarreled with a man named Thorgest to whom he had lent his ornamented high seat posts. The resulting bloodshed caused Eirik to be banished for three years. He took his ship and sailed boldly westward to explore some mysterious islands sighted by a drifting ship captained by a relative about a half-century earlier.
Armed with an invaluable body of sailing lore collected over generations by his kin, Eirik set off into unknown waters with a calm confidence that he would find new lands. Like other Norse skippers, he was an expert latitude sailor who used the su
n and North Star to stay on course. He also carried a s6larsteinn, or "sun stone," a bearing dial or sun compass in stone or wood that allowed a ship's captain with a knowledge of the sun's positions to steer by a thin radial shadow cast on the disk when held level in his hand. Eirik sailed westward, steering for some snowy peaks that loomed over the horizon when the expedition was still not far from Iceland. The sailors approached land, then coasted southward and westward until they reached a deeply indented coastline dissected by deep fjords behind sheltering offshore islands. They had reached southwestern Greenland.
They had the land to themselves, a place where green summer pastures and thick willow scrub offered pasture and fuel. The summers were brief and fairly warm, with longer days than Iceland. The winters were long and harsh, but the Norse were accustomed to climatic extremes. They found much better grazing land than that at home, abundant fish and sea mammals, and edible birds aplenty. Eirik sailed back to Iceland with glowing reports of a land so fertile he named it Greenland, "for he said that people would be much more tempted to go there if it had an attractive name."3
He must have been a persuasive leader, for twenty-five ships of potential colonists sailed back to Greenland with him. Fourteen reached what was soon called the Eastern Settlement, in the sheltered waters of the southwest in what are now the Julianehab and Narsaq districts. Eirik built his chieftain's seat at Brattahlid ("Steep Slope") in the heart of the richest farmland. At about the same time, another group of colonists pushed further north and founded the Western Settlement, centered around Sandnes Farm (Kilaarsarfik), in the modern-day Godthab district at the head of the sheltered Ameralik fjord. Life in Greenland was easier than on the crowded, hardscrabble fields of Iceland, with, as yet, no competition from indigenous Inuit people, plenty to eat, and harsh but usually endurable conditions at sea.