What Caused the little Ice Age

The Little Ice Age lasted around 350 years from the 15th century to the 19th century, causing social, economic and political problems. It was preceded by The Medieval Warm Period, an unusually warm time. Researchers have studied The Little Ice Age endlessly and advanced theories but no one really knows its cause.

What happened during the Little Ice Age? In the Northern Hemisphere temperatures dropped to very low levels, severe weather, heavy rain, snow, harsh winters, and flooding including from the sea, were constant features of The Little Ice Age.

The severe weather reduced crop harvests throughout Europe. Small harvests drive prices upwards and depress the economy. People spend more money on food and have less to spend on other things. Food shortages caused food riots and revolutions during the period. Meat was in short supply because poor harvests meant shortages of animal fodder. Starvation, malnutrition and opportune diseases associated with poor nutrition flourished during the Little Ice Age. Extremely bad harvests during some years of the period affected everyone, not just the poor. 

Contemporary accounts detail weather changes and their effects. Rivers, like the River Thames in London froze firmly enough to hold fairs on the ice. Peculiar weather events, heavy rainfall, blizzards and hail are all documented. Even Art was affected by the weather more paintings showed dark, snowy landscapes than before The Little Ice Age.

The Earth’s climate is naturally cyclical and there were other ice ages in history. The Little Ice Age provides clues to understanding the pre-historic ice ages because there is documentary evidence of the weather events, unusual occurrences and everyday life.

Some researchers say that The Little Ice Age was caused by high volcanic activity. There is some evidence for this; in 1815 Tambora, a volcano in Indonesia, had a major eruption sending huge amounts of ash into the atmosphere. 1816 was called “the year without a summer”, frost and snow occurred in June and July, in New England and much of Europe. The theory is that ash in the atmosphere blocked the sun’s rays from the earth.

Other scientists say a weak Gulf Stream caused The Little Ice Age. The Gulf Stream is the ocean current that carries warm water from the tropical mid- Atlantic up the Western Coast of Europe giving these countries more temperate weather than Labrador, Northern Canada, on the same latitude. Evidence for the weak Gulf Stream during The Little Ice Age came from sediment cores taken from The Florida Straits, the point at which The Gulf Stream enters The North Atlantic Ocean. The cores contain a calcified type of plankton, foraminifera, detected by the isotope, oxygen 18, which depends on the sea water’s salinity and temperature thus indicating the water’s density and flow. The Gulf Stream’s flow during the Little Ice Age was 10% less in volume than now.

Researchers at Utrecht University in The Netherlands point to another possible cause of The Little Ice Age; The Black Death in the 14th century. Historians reckon that up to 25 million people, a quarter of Europe’s population, died in The Black Death. The balance between cereal and tree pollen, and leaf data in cores taken from lake bed sediments in The Netherlands indicate millions of trees sprang up on abandoned farmland sucking up carbon dioxide from the atmosphere, thus cooling the climate.

The real causes of The Little Ice Age may be a combination of all these credible theories. The Earth goes through climactic cycles. Those who say that current climactic changes are not man-made always point to the climate’s cyclical nature. This ignores the fact that the present climactic change is happening too fast for it to be a completely natural phenomenon. Plants and animals cannot evolve and adapt quickly enough to survive. Humans should remember that, although they may be highly evolved, they are animals too and that they are the only animal that can do anything about modern climate change.