Guest Author - Helen B. Wharton

Watch the news on television or check the headlines on the internet, on any given day, and the chances are good there will be at least one story about Climate Change and Global Warming. Climatic fluctuations are not new. The climate of the Earth seems to follow a cyclic ebb and flow, sometimes globally, sometimes only regionally or only in one Hemisphere. In this article, the second of 2 about how weather may have influenced the history of the Medieval and Renaissance periods, we will look at the Little Ice Age.

The Little Ice Age was a period of very unstable climatic conditions with increased rain and floods, crop failures and very cold winters; lasting from the 14th Century to the 19th Century.

From the 9th Century to the 14th Century there was approximately 500 years of mild winters and stable weather known asThe Medieval Warm Period in which harvests were productive the population of Europe soared, and people thought it was permanent. People became dependent on cereal crops, like wheat, barley and oats, which thrived in the warm, stable climate.

Starting in the Autumn of 1314 the rain began. There is evidence of extremely cold, wet weather across Northern Europe which started very abruptly. For 5 years there was flooding, crops failed and previously arable lend became swamps. The cereal crops could not survive in the colder, wetter climate.

In a 10 year span the average annual temperature in the Northern Hemisphere dropped 4 degrees! This is a startling change in so short a period of time.

From 1315 to 1317 one of the worst famines in European history, The Great Famine, occurred. After years of cold, floods and famine, the people who were still alive were in a weakened condition when, in 1348 The Black Plague was introduced to Europe by ships from the East arriving in Genoa. The Plague ultimately lead to a 40% to 50% average reduction in the population of Europe.

There are several possible causes which scientists think may have contributed to the climatic changes of the Little Ice Age.

One theory is that the Medieval Warm Period may have caused melting of glaciers and polar ice which decreased the salinity of the Atlantic Ocean, resulting in a disruption of the Thermohaline Current. This could have caused the Gulf Stream to stall and the climate of Europe to chill.

Another event which could have contributed to the cold climate is decreased Solar, or Sun spot activity. The coldest part of the Little Ice Age, the years from 1645 to 1715 coincide with a period of very few Sun spots known as the Maunder Minimum.

During the Little Ice Age there was an increase in volcanic activity around the world. Each time a volcano erupts it puts a large amount of ash into the atmosphere that can block the Sun's warmth from reaching the surface of the Earth for up to 2 years. Volcanoes also release sulfur gas which turns into sulfuric acid when it reaches the outermost layer of the atmosphere, and has the ability to reflect sun light away from the Earth.

The effects of climate on culture and history can hardly be underestimated. The radical decline in population can be credited with an increased value of human life seen in the philosophy of Humanism, a hallmark of the Renaissance. The art of the Northern Renaissance is full of Winter scenes, the unique sound of Stradivarius violins can be, in part, the effect of dense wood from trees growing in a colder climate. The defeat of the Spanish Armada, off the coast of England, in 1588, is in part due to horrific weather.

The surprising thing, to me, is that during the Medieval Warm Period, when conditions were good, culture and history didn't change as amazingly as during the Little Ice Age, when millions died.