Wikibooks: Saylor.org's Ancient Civilizations of the World/The Development of the Neolithic Age in Africa, the Americas, Asia, and Europe

• Format: Book
• Language: English
• Subjects: Ice Sheet
• Online Access: https://en.wikibooks.org/wiki/Saylor.org%27s_Ancient_Civilizations_of_the_World/The_Development_of_the_Neolithic_Age_in_Africa,_the_Americas,_Asia,_and_Europe

=The Last Ice Age= Perhaps it would be better to call it the most recent Ice Age because in fact the Earth has had many Ice Ages. In fact climatologists people who study long term weather conditions have found at least four earlier ice ages and an older age for the Earth. Ice Ages tend to be similar every time they occur. The whole planet becomes significantly cooler and a vast majority of the planet s water becomes locked in ice at high altitudes and at the North and South Poles. Sea levels drop precipitously and a sheet of ice extends outwards from the poles and from high mountains like the Alps in Europe and the Rockies in North America to cover huge swaths of the planet s land area. The ice sheet can be more than a mile thick in places and the ice is so heavy and moves so forcefully in places that the underlying soil is ripped up and the bedrock below the soil is pummeled cracked and ground into huge boulders and tiny pebbles. Everywhere else sea levels drop about fifty feet shorelines in some places stretch outwards more than a mile beyond the present shores and numerous small islands and shoals appear even beyond that. The last Ice Age which geologists call the Würm III Ice Age lasted from about 20 000 years ago until about 15 000 years ago. All of Canada and much of the United States were swaddled in ice sheets as far south as Oregon Wyoming Illinois and Pennsylvania. Europe north of the Alps was almost totally covered as was much of central Russia. Tibet western China and northern India vanished under the ice buildup on the Himalayas. World temperatures dropped an average of 12° F enough to make even Florida or India unpleasantly cool. =Hunting and Gathering= Anthropologists believe that at the start of the last Ice Age the human population of Earth was less than a million people. Their existence revolved around a style of living which still exists today although it is gradually being wiped out everywhere by a combination of economic political and social pressures as well as outright violence. People ...