Global Warming Part 1

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Global Warming Part 1

• Sections 8.6.1 8.6.5

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Possible Global Warming Models 8.6.1

• Greenhouse Gasses
• Greenhouse gasses slow the rate of heat lost from
  Earths atmosphere. Since the rate of heat gained
  remains constant, heat builds up within Earths
  atmosphere.
• These gasses are produced in many ways, both
  natural and man-made.

• Solar Flares
• A solar flare results in an increase in energy
  emitted by the sun.
• These flares follow a predictable cycle.
• Solar flares are highly debated in relationship
  to global warming. Some scientists claim that it
  is responsible for 50 of the current warming of
  the Earth, while others regard the effects as
  negligent.

• Earths Orbit
• Some scientists claim that changes in Earths
  orbit result in increased temperatures on Earth
  due to decreased distance from the sun.
• There is a lack of evidence to back this claim
  and many believe that the effects would be very
  small unless the distance to sun varied by
  significant amounts.

• Volcanic Activity
• Volcanoes release many greenhouse gasses,
  including CO2, Cl2, and SO2.
• It is suggested that volcanic activity then leads
  towards an increase in Earthly temperature.
• Data shows the opposite, however. It has been
  found that particles put in the upper atmosphere
  by volcanoes actually reflect a portion of the
  suns radiation, cooling Earth.

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Enhanced Greenhouse Effect 8.6.2
The enhanced greenhouse effect simply refers to
human interaction with nature being a main or
significant cause of global warming.
Fossil Fuels and Global Warming 8.6.3
It is generally accepted that the burning of
fossil fuels by humans accounts for a large
portion of measured global warming. Fossil fuels,
when burned, release significant amounts of CO2
into the atmosphere, slowing the rate of heat
loss from Earth. Increased combustion leads to a
higher amounts of gasses in the air, slowing the
heat loss even more.
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Evidence Supporting Greenhouse Gasses 8.6.4

• What Was Found?
• Fairly simply, the evidence from Volstok and
  several other places in the world (such as
  Greenland) agree that there is a correlation
  between the concentration of CO2 and other
  greenhouse gasses and a rise in average
  temperature.
• This does not prove that one directly causes the
  other. Instead, it proves that the two tend to be
  related phenomena and there is very likely a
  strong link between them.

• Ice Core Samples
• Ice core samples are samples of ice taken where
  ice sheets pile on top of each other. Every year,
  different conditions effect the composition of
  the ice.
• Ice core samples can give data such as the time
  of the sample (usually by year), average
  temperature of the time period and the
  composition of the immediate atmosphere.

• Volstok, Antarctica
• Russian base in Antarctica.
• Ice Samples have been taken over 3000 meters
  deep. These samples go back approximately 420,000
  years and produce data about atmospheric
  composition and average temperatures.

Gasses vs. Temperature over 400,000 Years
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Increases in the Rate of Global Warming 8.6.5

• As Earths temperature increases, areas where ice
  and snow cover the ground melt and ground is
  exposed. Exposed earth absorbs much more energy
  than ice and snow (which reflect most of the
  energy back into the atmosphere). Therefore, as
  the temperature increases, the melting of snow
  and ice quickens the rate of temperature increase
  even more.
• The ability for CO2 to be soluble in water is
  dependant on temperature. As sea temperatures
  raise, CO2 tends to become much less soluble. The
  only place for this gas to escape is the
  atmosphere, where it becomes a greenhouse gas. As
  discussed earlier, greenhouse gas levels tend to
  relate directly to changes in temperature.

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8.6.5 continued

• Deforestation differs from the past two examples.
  Deforestation, almost solely caused by humans,
  decreases the rate at which CO2 is removed from
  the air (plants turn carbon dioxide and sunlight
  and break it into water vapor and oxygen). With
  less plants to turn the CO2 into O2, CO2 levels
  can build up more quickly than if deforestation
  did not exist.
• The last two examples are directly related to the
  enhanced greenhouse effect and the fact that
  humans have a large imprint on the amount of
  global warming we experience.

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Sources
http//www.daviesand.com/Choices/Precautionary_Pla
nning/New_Data/ http//volcanology.geol.ucsb.edu/
gas.htm http//www.ncdc.noaa.gov/oa/climate/globa
lwarming.html http//www.nasa.gov/worldbook/globa
l_warming_worldbook.html