16.2 Air Quality
KEY CONCEPT
Fossil fuel emissions affect the biosphere.
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Pollutants accumulate in the air.
• Pollution is any undesirable
factor added to the air, water, or
soil.
• Smog is one type of air pollution.
– sunlight interacts with
pollutants in the air
– pollutants produced by fossil
fuel emissions
– made of particulates and
ground-level ozone
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• Smog can be harmful to human health.
• Acid rain is caused by fossil fuel emissions.
– produced when pollutants in the water cycle cause rain
pH to drop
– can lower the pH of a lake or stream
– can harm trees
– can harm us if particulates are inhaled
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Air pollution is changing Earth’s biosphere.
• The levels of atmospheric carbon dioxide rise and fall over
time.
• High levels of carbon dioxide are typical of Earth’s warmer
periods.
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• The greenhouse effect slows the release of energy from
Earth’s atmosphere.
1. sunlight penetrates Earth’s atmosphere
2. energy is absorbed and reradiated as heat
3. greenhouse gases absorb longer wavelengths
4. Greenhouse
carbon dioxide
(CO )
gas molecules
methane (CH )
water (H O)
rerelease
infrared
radiation
2
4
2
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What is greenhouse gas and the green house effect?
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The Greenhouse Effect
• G.H.E. is naturally good (it
warms Earth)
• Problem: Excess CO2
absorbs excess heat near
the earth
• Fear: Climate patterns
change, ice caps melt
• Main Cause: CO2 from
burning of fossil fuels (coal,
oil, natural gas)
• Solutions: Reduce use of
fossil fuels, regrow trees,
alternative energy sources
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What’s in a name?
The purpose of
a greenhouse
is to trap heat
year round
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Earth
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Earth
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Earth
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The Greenhouse Effect
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The Greenhouse Effect in our solar system
Mars: No Greenhouse
Effect
Little heat is trapped by
the thin CO2
atmosphere.
Temperatures can be
around 20 F.
Venus: The Extreme
Greenhouse Effect
Heat is trapped by the
thick CO2
atmosphere.
Temperatures reach
750 F.
Earth: Balanced
Greenhouse Effect
Average global
temperature is 57 F.
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• Global warming refers to the trend of increasing global
temperatures.
North Pole