Lessons2and3thelittleiceage climate and change Edexcel Geography GCSE B
2.1bi What was it like during the little ice age? To know about the little ice age To understand its impacts on people and the environment Little Ice Age- period between 1300 and 1850 Specification Statement- Natural Climate in the past has affected people and ecosystems
<ul><li>Unusually low solar activity between 1645-1715 likely triggered the 'Little Ice Age' in regions like Europe and North America. A lag time of arguably 10-30 years allowed for the climate system to be affected by an increased ozone layer that altered the heating of the oceans. According to the model, diminished jet stream winds caused by a dimmer sun created cold land temperatures by reducing the transport of warm Pacific air to America and warm Atlantic air to Europe. During this shift, winter temperatures cooled as much as 2 to 4 degrees F - enough to freeze rivers and alter agriculture, economy, disease, etc. </li></ul><ul><li>Pictured is the climate model used by researchers to watch temperature anomalies. As such, 1780 was used as an arbitrary baseline; the ice age period, then, is colder/bluer and 1780 is white or neutral. Redder colours in more modern times reflect warmer temperatures. </li></ul>
<ul><li>MAIN IDEAS </li></ul><ul><li>The Little Ice Age was a period of unusually cool conditions between the years of 1300 and 1850 A.D. </li></ul><ul><li>Humans experienced increased illness and famine during the Little Ice Age. </li></ul><ul><li>Livestock survival and crop productivity decreased. </li></ul><ul><li>Cost of food increased due to shortages and low crop yields. </li></ul><ul><li>The Little Ice Age was preceded and followed by periods of warmer climates. </li></ul><ul><li>Between 1300 and 1850 many parts of the world experienced repeated unusually cool conditions that scientists have called the “Little Ice Age.” During these cooler times, winters were longer and colder than normal, and summers were shorter and cooler. </li></ul><ul><li>What do you think the living conditions would have been like during this time? </li></ul>
Background Information <ul><li>The Little Ice Age (1350-1850) was a period of particularly harsh climate conditions across most parts of the world. </li></ul><ul><li>Most of the documents that record information about the Little Ice Age come from Northern Europe because extensive records were kept. </li></ul><ul><li>A combination of decreased solar activity and numerous large volcanic eruptions cooled Earth’s climate. Cooling caused glaciers to advance and stunted tree growth </li></ul><ul><li>Livestock died, harvests failed, and humans suffered from increased famine and disease. </li></ul><ul><li>The Little Ice Age illustrates changes to climate that occur when the Sun is less active and cooling of Earth is exacerbated by volcanic eruptions. </li></ul><ul><li>Many other examples of climate change due to natural forces exist including the “year without a summer” which followed the 1815 eruption of Tambora, in Indonesia. </li></ul><ul><li>At an earlier time, Europe experienced a warm period which may have helped the Vikings to settle Greenland. </li></ul><ul><li>In order to understand the current climate change debate, one must understand the natural events and cycles that play an important role in determining climate on Earth. </li></ul>
Living during the Little Ice Age <ul><li>http://www.youtube.com/watch?v=GoNHk_pJlRo video 6.44 minutes CNN </li></ul><ul><li>Whilst watching this video make notes under the following headings </li></ul><ul><li>What were the impacts? </li></ul><ul><li>Who were most affected? How? Why? </li></ul><ul><li>What happened in Britain? </li></ul><ul><li>http://www.youtube.com/watch?v=aDXYx9eb7sE&feature=fvw bbc wild europe 4.02 </li></ul><ul><li>How far south did the ice sheet reach? </li></ul><ul><li>Which other European cities were ice covered? </li></ul><ul><li>How might London have looked ½ million years ago </li></ul><ul><li>How far did it reach in rest of Europe? </li></ul><ul><li>What bones are found in the mid North Sea? </li></ul><ul><li>What was North sea like during ice age? </li></ul>
50 40 30 20 20 QUESTION- How does the cost of grain in Germany change between 1500 and 1700?
How does the cost of grain change in Germany between 1500 to 1700? Are there years when grain is inexpensive and other years when it is expensive? What do you think might cause changes in the price of the grain?
<ul><li>Questions- </li></ul><ul><li>In what times was there less food to eat in Scotland? </li></ul><ul><li>How is climate related to grain in Germany and farming in Scotland? </li></ul>
Tasks <ul><li>Look at the graph handouts you have been given </li></ul><ul><li>In which years do you think life in Scotland was very difficult due to lack of food? </li></ul><ul><li>What conditions can cause the death of sheep? </li></ul><ul><li>What conditions do you think might cause a poor harvest? </li></ul><ul><li>How do you think that the death of sheep and a poor harvest combine to affect the conditions for people living in Scotland? </li></ul><ul><li>What happens to the death rate of humans when food is unavailable? </li></ul><ul><li>Which occurs first: harsh winter conditions, death of sheep, poor harvest, or famine? Why do you think so? </li></ul>
<ul><li>How do you think the painting shows the effects of weather or climate? </li></ul><ul><li>Do you think that artwork is based on reality or fiction? Explain your answer. </li></ul><ul><li>What additional information would you like to have in order to know if the artwork represents the real weather or climate conditions of the time? </li></ul>This scene, captured by the artist Peter Bruegel the Elder during 1565, depicts people engaged in a wide range of activities.
An account of one person’s life <ul><li>“ Even in the best of times, rural life was unrelentingly harsh...A Winchester farm worker who survived childhood diseases had an average life expectancy of twenty-four years. Excavations in medieval cemeteries paint a horrifying picture of health problems resulting from brutal work regimes. Spinal deformations from the hard labor of plowing, hefting heavy grain bags, and scything the harvest are commonplace. Arthritis affected nearly all adults. Most adult fisherfolk suffered agonizing osteoarthritis of the spine from years of heavy boatwork and hard work ashore...the human cost in constant, slow-moving toil was enormous. Yet despite the unending work, village diets were never quite adequate, and malnutrition was commonplace” </li></ul>
Impact on Forests During the Little Ice Age <ul><li>A study of the tree populations in forests of Southern Ontario by Campbell and McAndrews (1993) shows how the tree population in Europe might have been changed by the LIA. Their analysis of pollen demonstrated that after the year 1400, beech trees, the formerly dominant warmth-loving species, were replaced first by oak and subsequently by pine. Further, the forest under study appears to have remained in disequilbrium with the prevailing climate of today. That suggests that tree population distribution takes hundreds of years to recover from major climate changes. </li></ul>
Impact on Health <ul><li>The cooler climate during the LIA had a huge impact on the health of Europeans. As mentioned earlier, dearth and famine killed millions and poor nutrition decreased the stature of the Vikings in Greenland and Iceland. </li></ul><ul><li>Cool, wet summers led to outbreaks of an illness called St. Anthony's Fire. Whole villages would suffer convulsions, hallucinations, gangrenous rotting of the extremities, and even death. Grain, if stored in cool, damp conditions, may develop a fungus known as ergot blight and also may ferment just enough to produce a drug similar to LSD. (In fact, some historians claim that the Salem, Massachusetts witch hysteria was the result of ergot blight.) </li></ul><ul><li>Malnutrition led to a weakened immunity to a variety of illnesses. In England, malnutrition aggravated an influenza epidemic of 1557-8 in which whole families died. In fact, during most of the 1550's deaths outnumbered births (Lamb, 1995.) The Black Death (Bubonic Plague) was hastened by malnutrition all over Europe. </li></ul><ul><li>One might not expect a typically tropical disease such as malaria to be found during the LIA, but Reiter (2000) has shown that it was an important cause of illness and death in several parts of England. The English word for malaria was ague, a term that remained in common usage until the nineteenth century. Geoffrey Chaucer (1342-1400) wrote in the Nun's Priest Tale: </li></ul><ul><li>You are so very choleric of complexion. Beware the mounting sun and all dejection, Nor get yourself with sudden humours hot; For if you do, I dare well lay a groat That you shall have the tertian fever's pain, Or some ague that may well be your bane. In sixteenth century England, many marshlands were notorious for their ague-stricken populations. William Shakespeare (1564-1616) mentioned ague in eight of his plays. Oliver Cromwell (1599-1658) died of ague in September 1658, which was one of the coldest years of the LIA. </li></ul><ul><li>Five indigenous species of mosquito are capable of transmitting malaria in England where they prefer the brackish water along river estuaries. The anaerobic bacterial flora of saline mud produces a strong sulfur odor that was widely believed to be the cause of agues in salt marsh areas (i.e. Shakespeare's "unwholesome fens.") The term malaria comes from the Italian term " mala aria " meaning "bad air." </li></ul>
Impact on Economics- Negative <ul><li>In addition to increasing grain prices and lower wine production, there were many examples of economic impact by the dramatic cooling of the climate. Due to famine, storms, and growth of glaciers ,many farmsteads were destroyed, which resulted in less tax revenues collected due to decreased value of the properties (Lamb, 1995.) </li></ul><ul><li>Cod fishing greatly decreased, especially for the Scottish fisherman, as the cod moved farther south. The cod fishery at the Faeroe Islands began to fail around 1615 and failed altogether for thirty years between 1675 and 1704 (Lamb, 1995.) In the Hohe Tauern mountains of the Austrian Alps, advancing glaciers closed the gold mines of the Archbishop of Salzburg who was one of the wealthiest dukes in the empire. The succession of two or three bad summers where the miners could not rely on work in the mines caused them to find employment elsewhere, which resulted in an abrupt end to the mining operations (Bryson, 1977.) </li></ul>
Positive economic impacts <ul><li>Not all of the economic impact was bad. The fertile fishing grounds of the present day Newfoundland Banks were thought to have been found by fisherman in the late 1400's who were looking for the fish stocks that had deserted their former grounds as the result of the movement of colder waters from the north (Lamb, 1995.) </li></ul><ul><li>English fisherman benefited by the southern movement of herring normally found in the waters off Norway. This increase in deep-sea fishing helped to build the maritime population and strength of the country (Lamb, 1995.) The failure of crops in Norway between 1680 and 1720 was a prime reason for the great growth of merchant shipping there. Coastal farmers whose crops failed turned to selling their timber and to constructing ships in order to transport these timbers themselves (Lamb, 1995.) </li></ul>
Living during the Ice Age Task <ul><li>Answer the following questions in your book- </li></ul><ul><li>What was the little Ice Age? </li></ul><ul><li>When did it occur? </li></ul><ul><li>Using the videos, pictures and extracts you have been given describe the impact of the little Ice Age upon </li></ul><ul><li>People </li></ul><ul><li>Farming and agriculture </li></ul><ul><li>The environment </li></ul>
<ul><li>Climate changes were equally striking in other parts of the world. 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 Kiangsi Province, where they had been grown for centuries. In North America, the early European settlers also reported exceptionally severe winters. For example, in 1607-8 ice persisted on Lake Superior until June 1 st </li></ul>
<ul><li>http://www.geology.um.maine.edu/ges121/lectures/11-little-ice-age/little-ice-age.html article for pupils, use with world map and annotate to show how areas were affected </li></ul><ul><li>Read the article annotate your world map with the impacts of the little Ice Age in various places </li></ul>The Little Ice Age
2.1bii What was responsible for the mass extinction at end of little ice age? To understand the role of climate in extinction of megafauna at end of little ice age Megafaunal or "large-animal" extinctions
The sides of the argument… <ul><li>The four camps are known tongue-in-cheek as 1"overkill," 2"overchill," 3"overill," and 4"overgrill” </li></ul><ul><li>ARCHEOLOGIST GARY HAYNES, UNIVERSITY OF NEVADA RENO, AND OTHERS THINK THAT THE CONTINENT'S FIRST HUMAN HUNTERS , FRESH FROM SIBERIA, KILLED THE MEGAFAUNA OFF AS THEY COLONIZED THE NEWLY DISCOVERED LAND. </li></ul><ul><li>DONALD GRAYSON, AN ARCHEOLOGIST AT THE UNIVERSITY OF WASHINGTON, SEATTLE, ALONG WITH COLLEAGUE DAVID MELTZER OF SOUTHERN METHODIST UNIVERSITY, BELIEVES THAT CLIMATE CHANGES AT THE END OF THE PLEISTOCENE EPOCH TRIGGERED THE COLLAPSE. </li></ul><ul><li>MAMMALOGIST ROSS MACPHEE OF THE AMERICAN MUSEUM OF NATURAL HISTORY HAS ADVANCED THE IDEA, WITH VIROLOGIST PRESTON MARX, THAT A VIRULENT "HYPERDISEASE" BROUGHT BY THE FIRST AMERICANS MIGHT HAVE RACED THROUGH SPECIES WITH NO NATURAL IMMUNITY, BRINGING ABOUT THEIR DEMISE. </li></ul><ul><li>IN THE NEWEST HYPOTHESIS ADVANCED, GEOLOGIST JAMES KENNETT, U.C. SANTA BARBARA, AND COLLEAGUES PROPOSE THAT A COMET IMPACT OR AIRBURST OVER NORTH AMERICA DID IT. </li></ul>
<ul><li>Overkill </li></ul><ul><li>1960s, ecologist Paul Martin blamed first Americans for hunting the megafauna to extinction. </li></ul><ul><li>The timing seemed more than coincidental: Humans were thought to have arrived no earlier than about 14,000 years ago, and by roughly 13,000 years ago, most of the megafaunal species abruptly vanish from the fossil record. </li></ul><ul><li>Only 2 types of giants were killed at those 14 sites, mammoth and mastodon. There's no sign that early hunters preyed on giant ground sloths, short-faced bears, or the armadillo-like glyptodonts, for instance. (Forensic studies of a cache of Clovis tools found in 2008 suggest the Clovis people did hunt now-extinct camels and horses.) That's hardly enough evidence, Grayson and Meltzer argue, to lay blame for a continent's worth of lost megafauna at the foot of the first Americans. </li></ul><ul><li>"I don't care what anybody else says, 14 kill sites of mammoth and mastodon in a very short time period is extraordinary," It's one thing to find a campsite with some animal bones in it, he says, quite another to find the actual spot where an ancient hunter felled and butchered </li></ul><ul><li>"It's rare to find a kill site anywhere in the world,". And absence of other megafauna in kill sites doesn't mean they weren't hunted. "There is no doubt Native Americans were eating deer and bear and elk," Haynes says, citing several large mammals that pulled through. "But you cannot find a single kill site of them across 10,000 years." </li></ul><ul><li>The dearth of widely convincing evidence only serves as a spur. </li></ul><ul><li>Could what scholars agree must have been a relatively modest initial population of hunters have emptied an entire continent of its megafauna virtually overnight, geologically speaking? (In fact, it's three continents: South America and, to a lesser extent, Northern Eurasia also lost many large species at the end of the Ice Age.) </li></ul><ul><li>Certain populations of surviving big beasts, including bison in North America and musk oxen in Asia, are known to have fallen precipitously at the end of the Ice Age. "It gets a little bit beyond probability in my view that people could have been so active as to hunt every animal of any body size, in every context, in every possible environment, over three continents." </li></ul>
<ul><li>This map shows how catastrophic large-animal extinctions occurred around the world not long after humans first arrived in a geographical region. Australia and New Guinea suffered their mass extinctions between 15,000 and 30,000 years ago, North and South America theirs between 10,000 and 12,000 years ago, and oceanic islands like the Greater Antilles, major Mediterranean islands, New Zealand, and Madagascar theirs between 1,000 and 6,000 years ago. All these occurred in the wake of initial human colonization. Numbers indicate percentages of extinct genera during the past 100,000 years. </li></ul>
<ul><li>Overchill </li></ul><ul><li>Could climate change have done it? </li></ul><ul><li>Scholars generally agree that North America witnessed some rapid climate adjustments as it shook off the Ice Age beginning about 17,000 years ago. The most significant swing was a cold snap between about 12,900 and 11,500 years ago. Known as the Younger Dryas, this partial return to ice-age conditions may have stressed the megafauna and their habitats sufficiently to cause widespread die-offs, Grayson and others believe. </li></ul><ul><li>Detractors, again, point to the lack of evidence. "There aren't any deposits of starved or frozen or somehow naturally killed animals that are clearly non-cultural in origin that you would expect if there was an unusual climate swing," says Haynes. "I don't think that evidence exists." Another question dissenters have is how the megafauna survived many abrupt glacial and deglacial shifts during the past two million years only to succumb to the one that closed the Pleistocene. "It just doesn't hold water," Jim Kennett (overgrill) told me. </li></ul><ul><li>Grayson admits that overchill advocates have failed to develop the kind of records needed to test climate hypotheses in detail. But he focuses on climate change, he says, because he sees absolutely no sign that people were involved. "You can't look at climate and say climate didn't do it for the simple reason that we don't really know what to look for," Grayson told me. "But what you can do fairly easily is look at the evidence that exists for the overkill position. That position would seem to make fairly straightforward predictions about what the past should have been like, and when you look to see if it was that way, you don't find it." </li></ul>
<ul><li>Overill </li></ul><ul><li>The notion that diseases brought unwittingly by newly arriving people, either in their own bodies or in those of their dogs accompanying rats, could have killed off native species that had no natural immunity. MacPhee devised this hypothesis with Preston Marx after realizing that the link between initial human arrival and subsequent large-animal extinctions was strong not just in North America but in many other parts of the world, but that in his opinion, convincing evidence for hunting as the culprit simply did not exist. </li></ul><ul><li>Despite what he calls "prodigious effort" using DNA techniques and immunological probes, MacPhee and his colleagues have failed to detect clues to any pathogens in megafaunal bones, or nail down a specific disease, like rabies, that could have jumped from animal to animal and wiped out all the big beasts. "There's no evidence, and there's virtually no possibility of getting any evidence," </li></ul><ul><li>“ We can't prove there was hyperdisease," Haynes says. "We can prove people were here, and we can prove climates were changing." Fair enough, says MacPhee, though he points out that the burgeoning ability of Asian bird flu to infect across species boundaries seems to suggest that some diseases are ecologically and genetically preordained to, as he puts it, "go hyper." </li></ul>
<ul><li>Overgrill </li></ul><ul><li>The most recent hypothesis, advanced by Kennett and 25 other scientists in a 2007 Proceedings of the National Academy of Sciences paper, concerns the proposed cosmic impact. Right about the time the Younger Dryas began and at least 15 of those 35 extinct mammals vanish abruptly from the fossil record—that is, right about 12,900 years ago </li></ul><ul><li>According to Kennett, fieldworkers have uncovered fossils of the 15 mammals that survived right up to Younger Dryas times just beneath—Kennett and his team he works with charcoal, soot, microscopic diamonds, and other trace materials at the base of the mat. </li></ul><ul><li>These materials indicate, that a comet (not an asteroid—different constituents) exploded in the atmosphere or struck the surface, likely in pieces. This triggered widespread wildfires and extinctions, changed ocean circulation, and coughed up sun-blocking ash and dust, all of which helped unleash the Younger Dryas. Tokens of this cosmic cataclysm have shown up in the Greenland ice sheet as well </li></ul><ul><li>But sceptics can’t find a crater? Unlike the asteroid strike at the end of the Cretaceous, the one thought to have ended the reign of the dinosaurs, this 12,900-year-old event currently has no hole or holes definitively linked to it. Kennett says it's still early, noting that it took nearly a decade for scientists to discover the dinosaur-ending impact crater after evidence for a cosmic collision 65 million years ago first turned up in sedimentary layers around the world. </li></ul><ul><li>Then again, there may be no crater, Kennett says. He cites Tunguska: In 1908, an object that scholars believe was a meteor or comet exploded high above the Tunguska River in Siberia, leveling trees over 800 square miles but leaving no crater. </li></ul><ul><li>Finally, there are the extinctions themselves. Of the 35 extinct genera, 20 or so cannot be shown to have survived up to the Younger Dryas. The youngest date, for example, for fossils of Eremotherium , a giant ground sloth, is 28,000 years ago. "So the idea that this impact could have caused the extinctions of all these animals just does not make sense," Grayson says. In response, Kennett points out that the fossil record is imperfect, and one would not expect to see the most recent occurrence of rare forms like Eremotherium to extend right up to the Younger Dryas, as the remains of more common animals like mammoths, horses, and camels do. </li></ul>
Blame on hunting- Overkill <ul><li>http://news.bbc.co.uk/1/hi/sci/tech/8112885.stm Human role in big kangaroo demise </li></ul><ul><li>http://news.bbc.co.uk/1/hi/world/asia-pacific/7555206.stm Extinction 'by man not climate' </li></ul>
Blame on climate- Overchill <ul><li>http://news.bbc.co.uk/1/hi/sci/tech/8112885.stm </li></ul><ul><li>Climate key to big-beast demise video </li></ul><ul><li>http://news.bbc.co.uk/1/hi/sci/tech/4042693.stm bison show climate more likely responsible </li></ul>
Blame on comet (Overgrill) <ul><li>http://www.youtube.com/watch?v=1IrxFAFL-oc&feature=PlayList&p=741568C2D58A9793&index=7 video clip (5.37m) </li></ul><ul><li>http://ksjtracker.mit.edu/wp-content/uploads/2007/06/kerr-mammoth-killer.pdf article </li></ul>
Task <ul><li>Having looked at all the information on this debate- </li></ul><ul><li>What do you now believe was the role of climate in the extinction of mega fauna at the end of the last ice age? </li></ul><ul><li>Write a response to the question, remember talk about all theories about the role not just climate iTself </li></ul>
<ul><li>new NASA computer climate model reinforces the long-standing theory that low solar activity could have changed the atmospheric circulation in the Northern Hemisphere from the 1400s to the 1700s and triggered a "Little Ice Age" in several regions including North America and Europe. Changes in the sun's energy was one of the biggest factors influencing climate change during this period, but have since been superceded by greenhouse gases due to the industrial revolution. </li></ul>
<ul><li>http://www.dailygalaxy.com/my_weblog/2009/01/the-little-ice.html </li></ul>The Younger Dryas occurred at a time when orbital forcing should have continued to drive climate to the present warm state. The unexplained phenomenon has been the topic of much intense scientific debate, as well as other millennial scale events. Now an 11-year low in Sunspot activity has raised fears among a small number of scientists that rather than getting warmer, the Earth could possibly be about to return to another cooling period. The idea is especially intriguing considering that most of the world is in preparation for global warming. Could we be preparing for the wrong scenario? A sunspot is a region on the Sun that is cooler than the rest and therefore appears darker. One theory is that a strong solar magnetic field, which causes plenty of sunspot activity, protects the earth from cosmic rays, but that when the field is weak - during low sunspot activity - the rays can penetrate into the lower atmosphere and cloud cover increases, which in turn leads to a cooler surface. Geophysicist Phil Chapman, the first Australian to become an astronaut with NASA, notes that pictures from the US Solar and Heliospheric Observatory show that there are currently no spots on the sun. He believes this is the reason why the world cooled rapidly between January last year and January this year, by about 0.7C. "This is the fastest temperature change in the instrumental record, and it puts us back to where we were in 1930," Dr Chapman writes in The Australian today. "If the temperature does not soon recover, we will have to conclude that global warming is over."