8th Grade Science

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8th Grade Science

• Unit 7
• Changes in the Earth
• Lesson 2
• Global Warming Who Moved the Carbon?
• Vocabulary of Instruction

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1. Acid Rain

• Rain that has a pH lower than 7 because it
  contains nitric and sulfuric acids and other air
  pollutants dissolved in it.

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2. Emissions

• Substances discharged into the air, especially by
  internal combustion engines (airplanes, cars, and
  factories) due to the burning of fossil fuels.

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Yearly increase of atmospheric CO2. In the
1960s, the average annual increase was 37 the
2000-2007 average.
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Main symptoms of Carbon Dioxide toxicity in Humans
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3. Equilibrium

• State of natural balance within a community of
  organisms in which ecosystem diversity remain
  relatively stable.
• In some environments, succession reaches a
  climax, producing a stable community dominated by
  a small number of prominent species.

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Aquatic Ecosystem (Food Web) in Equilibrium
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(1) a climax forest (2) destroyed by wildfire and
(3 and 4) its eventual recovery. Secondary
succession occurs in an area where life once
existed but has then been destroyed.
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4. Fertilizer Runoff

• Fertilizers include natural (animal manure) and
  synthetic materials (nitrogen, phosphorus, and
  potassium compounds) that are spread on or worked
  into soil to increase its capacity to support
  plant growth.
• Runoff of soil and fertilizer is common during a
  rain storm which end up in rivers, lakes, and
  oceans.

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Old and Modern Fertilizer Spreader
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Decomposing animal manure, an organic fertilizer
source
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5. Global Warming

• The increase of greenhouse gas concentration
  (mainly carbon dioxide) that led to a substantial
  warming (increase in the average atmospheric
  temperature) of the earth and the sea that causes
  corresponding changes in the climate.

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Average Temperature Increase
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From which sectors do the major greenhouse gas
emissions come from? The lower part of the
picture shows the sources individually for the
gases carbon dioxide, methane and nitrous oxide,
respectively.
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6. Greenhouse Effect

• The greenhouse effect is caused by an atmosphere
  containing gases that absorb and emit infrared
  heat radiation, due to its absorption by
  atmospheric carbon dioxide, water vapor, methane,
  and other gases.

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Real Greenhouses used to grow plants under
controlled conditions
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7. Ozone Depletion

• The destruction of the protective layer of ozone
  in the upper atmosphere by chemical pollution. It
  is attributed to the presence of chlorine from
  manmade Chlorofluorocarbons (CFCs) and other
  forces. The layer is thinning because ozone is
  being destroyed at a faster rate than it is being
  regenerated by natural forces.

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Ozone Depletion Causes and Effects

• The blue and purple colors are where there is the
  least ozone, and the greens, yellows, and reds
  are where there is more ozone.

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Ozone Depletion Effects