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It was initially believed that the LIA was a global phenomenon; it is now less clear if this is true. The Intergovernmental Panel On Climate Change (IPCC), based on Bradley and Jones, 1993; Hughes and Diaz, 1994; Crowley and Lowery, 2000 describes the LIA as "a modest cooling of the Northern Hemisphere during this period of less than 1°C," and says, "current evidence does not support globally synchronous periods of anomalous cold or warmth over this timeframe, and the conventional terms of 'Little Ice Age' and Medieval Warm Period appear to have limited utility in describing trends in hemispheric or global mean temperature changes in past centuries." There is evidence, however, that the Little Ice Age did affect the Southern Hemisphere. DATING OF THE LITTLE ICE AGE There is no agreed beginning year to the Little Ice Age, although there is a frequently referenced series of events preceding the known climatic minima. Starting in the 13th Century , pack ice began advancing southwards in the North Atlantic , as did glaciers in Greenland. The three years of torrential rains beginning in 1315 ushered in an era of unpredictable weather in Northern Europe which did not lift until the 19th century. There is anecdotal evidence of expanding glaciers almost worldwide. In contrast a climate reconstruction based on glacial length shows no great variation from 1600 to 1850, though it shows strong retreat thereafter. For this reason, any of several dates ranging over 400 years may indicate the beginning of the Little Ice Age:
In contrast to its uncertain beginning, there is a consensus that the Little Ice Age ended in the mid-19th century. NORTHERN HEMISPHERE The Little Ice Age brought bitterly cold winters to many parts of the world, but is most thoroughly documented in Europe and North America . In the mid- 17th Century , glaciers in the Swiss Alps advanced, gradually engulfing farms and crushing entire villages. The River Thames and the Canal s and rivers of the Netherlands often froze over during the winter, and people skated and even held Frost Fairs on the ice. The first Thames frost fair was in 1607; the last in 1814, although changes to the bridges and the addition of an Embankment affected the river flow and depth, hence the possibility of freezes. The freeze of the Golden Horn and the southern section of the Bosphorus took place in 1622. The winter of 1794/95 was particularly harsh when the French invasion army under Pichegru could march on the frozen rivers of the Netherlands, whilst the Dutch fleet was fixed in the ice in Den Helder harbour. In the winter of 1780, New York Harbor froze, allowing people to walk from Manhattan to Staten Island . Sea ice surrounding Iceland extended for miles in every direction, closing that island's harbors to shipping. The severe winters affected human life in ways large and small. The population of Iceland fell by half, but this was perhaps also due to in Greenland died out (in the 15th century) because they could no longer grow enough food there. In North America, American Indians formed leagues in response to food shortages . "In many years, snowfall was much heavier than recorded before or since, and the snow lay on the ground for many months longer than it does today Many springs and summers were outstandingly cold and wet, although there was great variability between years and groups of years. Crop practices throughout Europe had to be altered to adapt to the shortened, less reliable growing season, and there were many years of death and famine (such as the Great Famine Of 1315-1317 , although this may have been before the LIA proper). Viticulture entirely disappeared from some northern regions. Violent storms caused massive flooding and loss of life. Some of these resulted in permanent losses of large tracts of land from the Danish , German , and Dutch coasts [http://www.cdc.gov/ncidod/eid/vol6no1/reiter.htm . The extent of mountain , Maryland , large temperature excursions during the Little Ice Age (~1400-1900 AD) and the Medieval Warm Period (~800-1300 AD) possibly related to changes in the strength of North Atlantic Thermohaline Circulation {Link without Title} . In Ethiopia and Mauritania , permanent snow was reported on mountain peaks at levels where it does not occur today. Timbuktu , an important city on the trans-Saharan caravan route, was flooded at least 13 times by the Niger River ; there are no records of similar flooding before or since. In China , warm weather crops, such as oranges, were abandoned in Jiangxi Province , where they had been grown for centuries. In North America, the early European settlers also reported exceptionally severe winters. For example, in 1607-1608 ice persisted on Lake Superior until June {Link without Title} . Antonio Stradivari , the famous Violin maker, produced his instruments during the LIA. It has been proposed that the colder climate caused the wood used in his violins to be denser than in warmer periods, contributing to the tone of Stradivari's instruments {Link without Title} . ''The Little Ice Age'' (Basic Books, 2000), by anthropology professor Brian Fagan of the University of California at Santa Barbara, tells of the plight of European peasants during the 1300 to 1850 chill: famines, hypothermia, bread riots, and the rise of despotic leaders brutalizing an increasingly dispirited peasantry. In the late 17th century, writes Fagan, agriculture had dropped off so dramatically that “Alpine villagers lived on bread made from ground nutshells mixed with barley and oat flour.” Finland lost perhaps a third of its population to starvation and disease. Life was particularly difficult for those who lived under the constant threat of advancing glaciers in the French Alps. One, the Des Bois glacier on the slopes of Mont Blanc, was said to have moved forward “over a musket shot each day, even in the month of August.” When the Des Bois threatened to dam up the Arve river in 1644, residents of the town of Chamonix begged the bishop of Geneva to petition God for help. In early June, the bishop, with 300 villagers gathered around him, blessed the threatening glacier and another near the village of Argentiere. For a while, salvation seemed at hand. The glaciers retreated for about 20 years, until 1663. But they had left the land so barren that new crops would not grow. Depictions of winter in European painting |
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