16.2 Air quality.ppt and human population

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1. 16.2 Air Quality
KEY CONCEPT
Fossil fuel emissions affect the biosphere.

2. 16.2 Air Quality
Pollutants accumulate in the air.
•Pollution is any undesirable
factor added to the air, water, or
soil.
•Smog is one type of air pollution.
•OZONE LAYER HOLE
CAUSED BY USE OF CFC’s =
AEROSOLS,
ETC….BANNED IN 1995

3. 16.2 Air Quality
•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

4. 16.2 Air Quality
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.

5. 16.2 Air Quality
•The greenhouse effect occurs when the gases act as a blanket (as an
insulator) that slows the release of energy and helps to keep the Earth at a
temperature that can support life = GOOD!
methane (CH
4) water (H
2O)
carbon dioxide
(CO
2)
1.Light emitted from the sun
comes to Earth
2.Energy is absorbed by the earth
and radiated as heat
3.Green house gases in the
atmosphere absorb wavelengths
of light
4.Molecules re-release infrared
radiation, which is re-absorbed or
lost to outer space.
--Water, Carbon dioxide and methane
are the 3 most common
greenhouse gases.

6. 16.2 Air Quality
•Global warming refers to the trend of increasing global
temperatures.
North Pole