A lecture from a physical science class

Narrator
Listen to part of a lecture from a physical science class.

Prof: The Little Ice Age, or L-I-A for short, was a period of climatic and social upheaval in the northern hemisphere that brought severe winters and bad, er, unpredictable weather to many parts of the world, particularly Northern Europe. People [false start] scientists disagree on the LIA's precise beginning and ending dates, but unusual weather has been documented from the early 1300s to the mid-1800s, and it made significant impacts on agriculture, economics, um, health, and, uh, politics, and produced weather phenomena that have not been experienced since. London's Thames River in London froze twice, for example, in 1607 and 1814, and in 1780 the entire New York harbor became frozen. People could actually walk from Staten Island to Manhattan!

The weather changes began about, oh, 1250, when icepacks in the North Atlantic Ocean and glaciers in Greenland began spreading south. In 1300, summers in Northern Europe began growing colder, and in 1315, three years of steady rains led to a European famine. Then, about 1550, glaciers throughout the world began to grow, er, expand, and in 16 - uh, 1650, the worldwide temperature dropped to a record low. This was the first of three times it would do so between then and 1850, which is generally considered the end of the LIA. What caused these dramatic climate changes? Scientists aren't sure. But during the LIA time period they have noted significantly decreased sunspot activity and an increased number of volcanic eruptions. Volcanoes emit ash that blocks sun radiation and can cool subsequent worldwide temperatures for as long as two years. A good example is the 1815 eruption of a volcano in Indonesia. The following year, 1816 is still called "the year without a summer."

OK. So whatever the cause, the cold winters and damp summers seriously hindered agricultural production in Northern Europe, as one might expect. At the coldest points of the LIA, the growing season in England was shortened by one to two months. Now, at that time this had a profound impact, because growers lacked the...they lacked the versatile seeds we have today, which can withstand harsher weather. We have some evidence that before the LIA, England rivaled France for wine production. But the, uh, plummeting temperatures of the 1400s inhibited the growth of grapes, which eventually wiped out vineyards in the British Isles. During the LIA farms in the extreme northern countries, such as, um, Switzerland and Norway, remained buried in snow well into spring, which affected not only crops but also starved the livestock that fed off of hay. In France, a failed crop harvest in 17 -- I'm sorry, 1693 -- resulted in a famine that killed millions of people. This was the second famine attributed to the LIA. Economically, the events sparked by the LIA, such as storms, glacier growth, and famines, destroyed farms and depleted fisheries. This in turn led to decreased tax revenues. It even affected one of the wealthiest men in the world -- the Archbishop of Salzburg. When glaciers expanded in the Austrian Alps, they buried his gold mines. Ah, poor soul!

So. Although the agricultural and economic consequences of the LIA were severe indeed, its most dire impact was on human health. It completely wiped out one entire Northern European group during the 1400s -- the Greenland Vikings -- because they couldn't grow enough food to survive. The population of Iceland was halved, perhaps due to disease caused by a volcanic eruption there in 1783. The suddenly damp summers caused grain to develop a fungus called ergot blight. This produced a disease, -- called Saint Anthony's Fire -- that caused convulsions, gangrene, and even death. Um, in addition, general malnutrition during the LIA weakened people's immune systems, leaving them vulnerable to a variety of diseases, including the Bubonic Plague that killed about 25 million Europeans in the mid-1300s, as well as outbreaks of influenza and, uh, malaria in England, where the death rate was greater than birth rate for most of the 1550s.

Can you imagine that? People were dying faster than they were being born, the skies were likely dark, food was scarce. It must have seemed like the end of the world. So, it might not be surprising that those who survived the worsening climate of the LIA became more and more desperate, and began to demonstrate in a series of public outbursts. Residents of the Scottish highlands raided lowland cattle, killing King James I in 1436 while the king hunted at the boundary of the Highland region. In the bitterly cold winter of 1709, which killed lots of people in France, citizens in many cities rioted to pre [false start] to stop merchants from selling off the precious remaining little wheat that they had. Some historians attribute one of the world's most famous quotations partially to the effects of the LIA. In 17 eighty [pause] eight, yeah 1788, northern France suffered a severe winter followed by an unusually hot summer and a July hailstorm, which shriveled up the grain. This led to demonstrations -- riots, in fact -- the following year due to lack of bread. And it was during these riots that Queen Marie Antoinette allegedly said, "Let them eat cake," the words that helped precipitate the French Revolution.

Prof: Well, at any rate, in the mid-1800s -- 1850, as we've said -- the climate in the Northern Hemisphere began warming again, and it's been getting steadily hotter to this day. New evidence suggests that the Little Ice Age, whatever year it began, ended abruptly, perhaps within as few as 10 years. In its place comes a new concern: climate changes caused by global warming.