skies were less cloudy than now.35 With the glaciers in the Alps during the late Bronze Age being only about 20 percent of the size of the ice in the nineteenth century, merchants made their way through the Brenner Pass, the dominant link between northern and southern Europe. Northern Europeans exchanged tin for manufactured bronze from the south. Alpine people mined gold and traded it for goods crafted around the Mediterranean. Prior to around 2500 to 1750 B.C., northwestern India, which is now very dry, enjoyed greater rainfall than it does in the twentieth century.36 In the Indus Valley, the Harappas created a thriving civilization that reached its apogee during the warmest and wettest periods, when their farmers were growing cereals in what is now a desert.37 The area was well watered with many lakes. This civilization disappeared around 1500 B.C. at a time when the climate became distinctly drier.38 Virtually all change can make some worse off and the warming after the last Ice Age is no exception. As the ice sheets melted, the sea level rose sharply and probably peaked around 2000 B.C.39 Although as the population explosion indicates most humans benefited, the growing warmth harmed some people, especially those who lived near the coast or who had earned their living hunting large animals. During the many centuries in which the waters mounted, storms often led to ocean flooding of coastal communities. Cooler, More Varied, and Stormy Times From the end of the Optimum period of sustained warmth until around 800 A.D. to 900 A.D., what we know of the world's climate and, in particular, the European varied between periods of warmth and cold. Based on the height of the upper tree lines in middle latitudes' mountains, the temperature record following the peak warm period around 5000 B.C. demonstrates a more or less steady decline right up to the 20th century.40 Tree ring data for New Zealand indicate that after temperatures reached a maximum around 6000 to 8000 B.C., the climate subsequently cooled in that part of the world. After 1000 B.C. the climate in Europe and the Mediterranean cooled sharply and by 500 B.C. had reached modern average temperatures.41 The period from 500 B.C. to 600 A.D. was one of varied warmth, although cooler on average than the previous 4,500 years. However, the climate became more clement and somewhat more stable from 100 35Lamb [1977]: 254. 36Lamb [1977]: 251. 37Lamb [1977]: 389. 38Claiborne [1970]: 295. 39 Lamb [1977]: note 1, p. 257. 40Lamb [1982]: Fig. 43, p. 118. 41Lamb [1988]: 22. B.C. to 400 A.D., the period of the Roman Empire.42 The Italians grew grapes and olives farther north than they had prior to this period. During these centuries of varied weather, Classical Greece flourished and then declined; the Roman Empire spread its authority through much of what is now Europe, the Middle East and North Africa, only to be overrun by barbarians from central Asia whose eruption out of their homeland may have been brought on by a change in the climate. After 550 A.D. until around 800, Europe suffered through a colder, wetter, and more stormy period. As the weather became wetter, peat bogs formed in northern areas.43 The population abandoned many lakeside dwellings while mountain passes became choked with ice and snow, making transportation between northern Europe and the south difficult. The Mediterranean littoral and North Africa dried up, although they remained moister than now. Inhabitants of the British Isles between the seventh and the ninth centuries were often crippled with arthritis while their predecessors during the warmer Bronze Age period suffered little from such an affliction. Although some archaeologists have attributed the difficulties of the dark age people to harder work, the cold wet climate between 600 and 1000 A.D. probably fostered such ailments.44 The High Middle Ages and Medieval Warmth From around 800 A.D. to 1200 or 1300, the globe warmed considerably and civilization prospered. This Little Climate Optimum generally displays, although less distinctly, many of the same characteristics as the first climate optimum.45 Virtually all of northern Europe, the British Isles, Scandinavia, Greenland, and Iceland were considerably warmer than at present. The Mediterranean, the Near East, and North Africa, including the Sahara, received more rainfall than they do today.46 North America enjoyed better weather during most of this period. China during the early part of this epoch experienced higher temperatures and a more clement climate. From Western Europe to China, East Asia, India, and the Americas, mankind flourished as never before. The timing of the medieval warm spell, which lasted no more than 300 years, was not synchronous around the globe. For much of North America, for Greenland and in Russia, the climate was warmer between 950 and 1200.47 The warmest period in Europe appears to have been later, roughly between 1150 and 1300, although parts of the tenth 42Lamb (1988): 23. 43Lamb [1968]: 63. 44Lamb [1977]: 261. 45 Lamb [1968]: 64. 46Lamb (1968): 64-65. 47Lamb [1977]: 435. century were quite warm. Evidence from New Zealand indicates peak temperatures from 1200 to 1400. Data on the Far East is meager but mixed. Judging from the number of severe winters reported by century in China, the climate was somewhat warmer than normal in the ninth, tenth, and eleventh centuries, cold in the twelfth and thirteenth and very cold in the fourteenth. Chinese scholar Chu Ko-chen reports that the eighth and ninth centuries were warmer and received more rainfall, but that the climate deteriorated significantly in the twelfth century.48 He found records, however, that show that the first half of the thirteenth century was quite clement and very cold weather returned in the fourteenth century. 7.49 The evidence for Japan is based on records of the average April day on which the cherry trees bloomed in the royal gardens in Kyoto. From this record, the tenth century springs were warmer than normal; in the eleventh century they were cooler, the twelfth century experienced the latest springs; the thirteenth century was average and then the fourteenth was again colder than normal.50 This record suggests that the Little Climate Optimum began in Asia in the eighth or ninth centuries and continued into the eleventh. The warm climate moved west, reaching Russia and central Asia in the tenth through the eleventh, and Europe from the twelfth to the fourteenth. Some climatologists have theorized that the Mini Ice Age also started in the Far East in the twelfth century and spread westward reaching Europe in the fourteenth.51 Europe The warm period coincided with an upsurge of population almost everywhere, but the best data are for Europe. For centuries during the cold damp "dark ages" the population of Europe had been relatively stagnant. Towns shrank to a few houses clustered behind city walls. Although we lack census figures, the numbers from Western Europe after the climate improved show that cities grew in size; new towns were founded; and colonists moved into relatively unpopulated areas. - it had The change in the climate from a cold, wet one to a warm, drier climate more rainfall, but more evaporation reduced bogs and marshy areas must have played a significant role. In the eighth through the eleventh centuries, most people spent considerable time in dank hovels avoiding the inclement weather. These conditions were ripe for the spread of disease. Tuberculosis, malaria, influenza, and pneumonia undoubtedly took many small children and the elderly — those over 30. 48Ko-chen [1973]: 235. 49Ko-chen [1973]: 237 & 238. 50Lamb [1977]: Tables 17.3 and 17.4, pp. 443 & 447. 51Ko-chen [1973]: 239-240. With a more pleasant climate people spent longer periods outdoors; food supplies were more reliable. Even the homes of the peasants would have become warmer and less damp. The draining or drying up of marshes and wetlands reduced the breeding grounds for mosquitoes that brought malaria. In all the infant and childhood mortality rate must have fallen spawning an explosion in population. The warmth of the Little Climate Optimum made territory farther north cultivable. In Scandinavia, Iceland, Scotland, and the high country of England and Wales, farming became common in regions which neither before nor since have yielded crops reliably. In Iceland, oats and barley were cultivated. In Norway, farmers were planting further north and higher up hillsides than at any time for centuries. Greenland was 4° to 7°F warmer than at present and settlers could bury their dead in ground which is now permanently frozen. Scotland flourished during this warm period with increased prosperity and construction.52 Greater crop production meant that more people could be fed, and the population of Scandinavia exploded.53 Farmers and peasants in medieval England launched a thriving wine industry south of Manchester. Good wines demand warm springs free of frosts, substantial summer warmth and sunshine without too much rain, and sunny days in the fall. Winters cannot be too cold — not below zero Fahrenheit for any significant period. The northern limit for grapes during the Middle Ages was about 300 miles above the current commercial wine areas in France and Germany. These wines were not simply marginal supplies, but of sufficient quality and quantity that, after the Norman conquest, the French monarchy tried to prohibit British wine production.54 The rapid growth in numbers in turn propelled and sustained the Viking explorations and led to the foundation of colonies in Iceland and Greenland. In addition to the land north of the Alps, the warm rainier climate benefited southern Europe, especially Greece, Sicily and southern Italy. All of the Mezzogiorno in the Middle Ages did well.55 In the West, Charlemagne, creator of the Holy Roman Empire, may have inaugurated the era of the High Middle Ages while Dante, writing The Divine Comedy, may have closed it. In A History of Knowledge, Charles Van Doren contended that: “the ... three centuries, from about 1000 to about 1300, became one of the most optimistic, prosperous, and progressive periods in European history."56 All across Europe, the 52Lamb [1977]: 437. 53 Claiborne [1970]: 348-364. 54Lamb [1977]: 277. 55 Cheetham [1981]: 37. 56yan Doren [1991]: 111. population went on an unparalleled building spree erecting at huge cost spectacular cathedrals and public edifices. Byzantine churches gave way to Romanesque, to be replaced in the twelfth century by Gothic cathedrals. Virtually all the magnificent religious edifices that we visit in awe today were started by the optimistic populations of the eleventh through the thirteenth centuries, although many were not finished for centuries. In southern Spain, the Moors laid the cornerstone in 1248 for perhaps the world's most beautiful fortress, the Alhambra. Economic activity blossomed throughout the continent. Banking, insurance, and finance developed; a money economy became well established; manufacturing of textiles expanded to levels never seen before. Farmers were clearing forests, draining swamps and expanding food production to new areas.57 Starting in the eleventh century European traders developed great fairs that brought together merchants from all over Europe. At their peak in the thirteenth century they were located on all the main trade routes and served not only to facilitate the buying and selling of all types of goods but also functioned as major money markets and clearing houses for financial transactions. During the High Middle Ages, technology grew rapidly. New techniques expanded the use of the water mill, the windmill, and coal for energy and heat. Sailing improved through the invention of the lateen sail, the sternpost rudder and the compass. Governments constructed roads and contractors developed new techniques for use of stone in construction. New iron casting techniques led to better tools and weapons. The textile industry began employing wool, linen, cotton, and silk and, in the thirteenth century, developed the spinning wheel. Soap, an essential for hygiene, came into use in the twelfth century. Mining, which had declined since the Romans, at least partly because the cold and snow made access to mountain areas difficult, revived after the tenth century. The Arctic From the ninth through the thirteenth centuries agriculture spread into northern Europe and Russia where it had been too cold to produce food before. In the Far East, Chinese and Japanese farmers migrated north into Manchuria, the Amur Valley and northern Japan.58 As mentioned above, the Vikings founded colonies in Iceland and Greenland, a region that may have been more green than historians have claimed. It was also during this period that Scandinavian seafarers discovered “Vinland”. somewhere along the East Coast of North America. Viking explorers were venturing into Greenland, 57 Bartlett [1993]: 2. 58McNeill [1963]: 559. |