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Environmental History Chapter 2. Early history  Earth has existed for an estimated 4.6 billion years  Homo sapiens have been on earth only about 60.000.

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Presentation on theme: "Environmental History Chapter 2. Early history  Earth has existed for an estimated 4.6 billion years  Homo sapiens have been on earth only about 60.000."— Presentation transcript:

1 Environmental History Chapter 2

2 Early history  Earth has existed for an estimated 4.6 billion years  Homo sapiens have been on earth only about 60.000 years  Until about 12,000 years ago men were mostly hunter-gatherers.

3 Major Cultural Changes  Agricultural revolution  Industrial revolution  Information and globalization revolution

4 Hunter-gatherers  Survived by eating edible wild plants, fishing, hunting, and scavenging meat killed by other animals  Lived in small bands  Were nomads  They discovered: –Which plants and animals could be eaten and used as medicine –Where to find water –How plant availability changed throughout the year –How game animals migrated

5 Advanced hunter gatherers  Used more advanced tools and fire  Contributed to the extinction of some animals (saber-toothed tiger)  Altered distribution of plants by carrying seeds  OVERALL IMPACT ON THE ENVIRONMENT WAS LOW DUE TO: –Small population –Low resource use/person –Migration allowed ecosystem to repair itself –Lack of technology

6 Agricultural revolution  10,000-12,000 years ago  Also called Neolithic revolution  Gradual shift from nomads to settling in agricultural communities  Domesticated animals and cultivated wild plants

7 Slash-and- burn cultivation  Clear forest (mainly in the tropics)  Burn vegetation and underbrush  This adds nutrients to the soil – which is often nutrient poor  Led to Shifting cultivation

8 3 Harvesting for 2 to 5 years 1 Clearing and burning vegetation 2 Planting 4 Allowing to revegetate 10 to 30 years

9  Most early farmers practiced SUSTAINABLE CULTIVATION  Had little impact on the environment because: –Depended on human muscle power and crude tools –Low population size and density –Land was available for movement to other areas

10 The Industrial Revolution

11  Began in England  Based on dependence on coal (nonrenewable fossil fuel) rather than renewable wood  Invention of the steam engine  Switched from small-scale localized production to large-scale production of machine-made goods.  Movement from rural to cities –Often very bad living and working conditions

12 Resulted in:  Fossil-fuel powered farm machinery  New plant-breeding techniques increasing yield per acre  More reliable food supply  Longer life spans  Increase in population size

13 Information and Globalization Revolution  Many new technologies – telephone, computers, tv, etc  Automated data bases  Remote sensing satellites

14  Positively –Helps us understand earth, economics, etc. –Allows use of remote sensing satellites –Enables use to develop computer models –Can reduce pollution and environmental degredation  Negatively: –Information overload –Confusion and a sense of hopelessness –Increases environmental degradation and decrease in cultural diversity

15 History of United States  Tribal Era –Occupied by indigenous people, called Indians – now called Native Americans –Had a fairly low environmental impact

16 Frontier Era (1607-1890)  Began with European colonists settling North America  Had a FRONTEIR ENVIRONMENTAL WORLDVIEW  The wilderness was there to be conquered and cleared. –Kill the dangerous animals and Native Americans


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