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Global warming
• Global warming:
Refers to the recent and ongoing rise in global average temperature near Earth's surface.
» Is caused mostly by increasing concentrations of greenhouse gases in the atmosphere.
» Is causing climate change.
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• Climate change:
» Refers to any significant change in the measures of climate lasting for an extended period of time.
» Includes major changes in temperature, precipitation, or wind patterns, among other effects, that occur over several decades or longer

Global warming
Earth Temperature
• Planet Earth maintains a relatively even steady temperature due to its atmosphere.
• Earth’s atmosphere produces a natural greenhouse effect to insulate Earth from temperature swings.
• Without the natural greenhouse effect, the Earth's average temperature would be much colder, and the planet would be covered with ice.
– The greenhouse effect that protects us can also be dangerous if we cause it to grow too strong.

Global warming
Earth Temperature
• The Earth's average temperature has increased about 1 degree Fahrenheit during the 20th century.
• Small changes in temperature correspond to enormous changes in the environment.
• At the end of the last ice age, the Northeast United States was covered by more than
3,000 feet of ice. The average temperatures were only 5 to 9 degrees cooler than today.

Global warming
Earth’s Atmosphere Gases:
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Nitrogen (N)
Oxygen (O2)
Argon (Ar)
Water Vapor (H2O)
Carbon Monoxide (CO2)

Global warming
Greenhouse Gases Effects
Natural greenhouse gases in the atmosphere are the substances that trap heat and insulate Earth from temperature swings:
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Water vapor (H2O)
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Ozone (O3)

Global warming
Human activity intensified the growth of greenhouse gases:
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Fossil fuel use is the primary source of carbon dioxide:
C7H16+11O2 = 7CO2+8H2O
2.