February 11, 2008
The truth is global warming is responsible for humans. Historically, both in the short term and in the long run, periods of elevated temperature have been associated with economic prosperity and population growth while cold periods are correlated to financial hardship and population contraction.
Prior to the latest global warming event that started more than 20,000 years, human beings existed in small family bands involved in hunting and gathering. With the retreat of the glaciers and the northward moving climate, these nomadic groups gradually developed intensive agriculture techniques as a precursor to civilization. A surplus of food allows for the division of labour and development of a social organization, because those not producing food can direct their efforts in other fields such as arts, industry, war, science or religion.
The earliest civilizations found so far are two 15,000-year-old now submerged metropolises found under the Bay of Khambhat, 250 km northeast of Bombay, India. These two cities were abandoned after being inundated by rising sea levels caused by the receding continental glaciers (sea level rise was greatest between 15,000 and 7,000 years ago). As the Khambhat communities disappeared other societies developed simultaneously, throughout India, China and the Middle East shortly thereafter.
After gradually rising from a paltry 1 million people 12,000 years ago, the world population reached a plateau between 200 and 900 AD. The advent of the Medieval Warm Period (MWP) in the 10th century started a phase of rapid population growth as surpluses of food were able to feed an ever-growing throng of people.
During this climatic anomaly, as with every warming event, the plant climatic zones moved northward. Grapes, which were previously grown only to the south in France, were now part of a flourishing wine industry in Britain. The Vikings took advantage of the ice-free seas at this time to establish colonies in Greenland and L’Anse Aux Meadows on the northern tip of Newfoundland.
Following on the heels of the MWP was the Little Ice Age (LIA), a period of temperature reversal characterized by the resurgence of European glaciers, the growth of Atlantic pack ice, and the destruction of crops and livestock as a result of shorter and unreliable growing seasons. Population crashes occurred periodically as the shortage of food caused widespread famine. Many who did not actually die of starvation, were so weakened from lack of food, they easily succumbed to a multitude of diseases caused by bacterial and viral infections.
The negative effects of the LIA were felt in other aspects of life as well. The colder weather caused massive storms that resulted in permanent massive losses of coastal area in the low-lying areas of Germany, Denmark and Holland. Viticulture disappeared from northern regions, and an increase in pack ice cut off the supply route to the many northern communities including Iceland. The Viking colonies in Greenland, now isolated from outside trade, all perished of starvation.
But the LIA was not all gloom and doom. The Thames River and the canals in Holland began freezing to such an extent that skating became a popular winter pastime. Festivals called frost fairs were held on the ice in winter and it was from this era that the story of Hans Brinker and the silver skates was written.
The cold weather at this time is also attributed the superb sound of the Stradivarius violins. A modern theory proposes that during the cold weather, the growth rings on the trees grew closer together. The denser wood was responsible in part with the tonal qualities that make his musical instruments renowned.
In the shorter term, colder than normal weather aberrations are always associated with economic downturn. Probably the best example of this correlation occurred in is 1816 as a result of the 1815 eruption of Mount Tambora. Also known as the “Year Without Summer”, “The Poverty Year” and “Eighteen Hundred and Froze to Death” 1816 saw devastated crops throughout the northern hemisphere. The crop failures caused North American prices of grain to increase as much a 700%, while food shortages in Europe resulted in widespread famine.
Besides the year without summer, 1915 and 1992 are two of the coldest years in Canada since records were kept. In each of these two years saw major economic repercussions in agriculture and business. The 1992 episode saw freak summer hailstorms and snowstorms in Ontario, early frost across the prairies and stormy weather across the Maritimes. The unseasonably cold weather negatively affected crops, tourism, construction, and even summer beer sales to the tune of half a billion dollars.
Although advances in technology and logistics of food distribution will reduce the impacts of future short-term temperature decreases, a long-term climate reversal however, could spell catastrophe for billions of people worldwide. Since most of the earth’s land area is located in the northern hemisphere, a progressively warmer climate will add millions of acres of arable land in Canada and Russia as the plant climate zones move northwards. Another cooling episode like the LIA would not only decrease the amount of arable land but reduce the yields as well, severely restricting the amount of food to feed the ever-growing world population.