Apple Demonstration

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Apple Demonstration
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Essential Question

• How do humans change the physical environment?

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Land vs. Water

• ¾ of world is water
• ¼ of world is land
•  

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Uninhabitable land

• Land that people cannot live on.
• Examples Mountains, Deserts
• ½ of land is uninhabitable

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Habitable Land

• Land that people can live on.
• 1/8 of world is habitable.

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Arable Land

• Land that can grow crops.
• 1/32 of world is arable.

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Unarable Land

• Land that cannot grow crops.

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Remember we do not live in the core or the
mantle.
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We live on the crust.
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Topsoil

• Not just the soil on Top. ?
• Soil that has nutrients needed to grow crops.
•  

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Renewable resource

•  A resource that the earth can reproduce.
• Example Trees

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Non-renewable resource

• A resource that the earth cannot reproduce.
• Example Fossil Fuels

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Facts on topsoil

•  Topsoil reproduces at the rate of 1 inch per 500
  years.
• USA currently loses 1 inch per 16 years.  
• In 1800 the US had 21 inches of topsoil.
• In 2000 the US had 6 inches of topsoil.
• At this rate, the US could have zero topsoil by
  the year 2096.

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Causes of topsoil loss

• Deforestation
• Construction
• Over-farming
• Over-grazing

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Over-Grazing Fact

• The land used to feed all the cows on the earth
  could grow enough food to feed 8.7 billion humans.

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Homework

• Write a letter to the editor explaining the
  problem with topsoil loss.
• Offer a solution for how one organization could
  establish better practices to help preserve
  topsoil.