Chapter 23 Lesson 2

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Chapter 23 Lesson 2
2
The Environment

• The Earths temperature is rising.
• Process called global warming.
• Gradual increase in the average temperature of
  Earths surface.
• Scientist agree that the temperature is rising
  but they cannot agree on why it is rising.

3
The Environment

• Carbon Dioxide and other gases trap heat in the
  Earths atmosphere.
• Process called the greenhouse effect.
• Some scientist think that carbon dioxide has
  increased by as much as 25 since the mid 1800s.
• Caused mostly by burning of fossil fuels.

4
The Environment

• In the 1960s many people became aware of how the
  actions of humans were affecting the environment.
• Believed that economic development was harmful to
  nature.
• Rachel Carson
• Scientist who wrote Silent Spring
• Described how pesticides (chemicals used to kill
  insects) were also killing birds.

5
The Environment

• Carson wrote in her book
• Early mornings are strangely silent where once
  they were filled with the beauty of bird song.
• Silent Spring convinced some people to become
  environmentalist.
• Person who favors taking measure to protect
  Earths natural environment.
• Congress set up the Environmental Protection
  Agency in 1970.
• Serves as a watchdog for the environment.
• Congress later passed laws to protect endangered
  species.
• Animals and plants that could die out.
• Green Political Parties formed in Europe.
• Work to pass environmental laws.

6
Problems and Solutions

• Some environmentalist think that global warming
  will continue unless people take steps to slow or
  stop it.
• Kyoto Protocol
• Officials from 160 countries met in1997 to sign a
  treaty that urged the countries to reduce the
  production of greenhouse gases.
• Most nations have not adopted the treaty because
  they believe it will disrupt their economies.
• Must be ratified by 55 countries.

7
Problems and Solutions

• Another problem the world faces is feeding the
  rapidly growing populations.
• Deforestation is occurring where farmers cut down
  trees to grow crops.
• Deforestation of rainforest in South America,
  Africa, and Southeast Asia has added to global
  warming.
• Removes trees that absorb carbon dioxide.
• As a result people have started planting trees.

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Problems and Solutions

• Global warming not the only example of climate
  change caused by human activity.
• Desertification
• Process of loosing land that was once fertile.
• Farmers plow fields and animals overgraze the
  land.
• Topsoil becomes loose, dries up, and blows away.
• Devastating to parts of Africa.
• Great American Dust Bowl of the 1930s.

9
Problems and Solutions

• The effect on the environment has also reached
  the poles of the Earth.
• Antarctica
• Fifth largest continent on Earth and the last one
  to be explored.
• Only scientist live there.
• Tourism has grown in recent years.
• 15,000 tourist visit there each year.

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Problems and Solutions

• People leave rusted cans and plastic wrappers.
• Polluted parts of Antarctica.
• Process of making the environment dirty.
• Garbage is a visible form of pollution.
• A solution is to recycle aluminum, paper, and
  glass.