Global Warming

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Global Warming

• by Alex Kiss

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Natural Warmth

• The Earths surface is heated primarily by
  sunlight
• It radiates long wavelength photons of Infrared
  (IR)
• Certain greenhouse gases trap some escaping
  radiation, exciting them to vibrate and rotate,
  effectively heating the air. Examples CO2, CH4,
  N2O, O3, H2O

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Consequences

• Without this natural greenhouse effect acting
  as a blanket, temperatures near the surface would
  be around -18C (0F)
• Instead the average is 15C (59F), which is warm
  enough to assure a liquid ocean and conditions
  suitable for life

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Pollution

• Since the Industrial Revolution, atmospheric
  concentrations of naturally occurring greenhouse
  gases
• Carbon dioxide has increased by 30
• Methane has more than doubled
• Nitrous oxide has risen by more than 15
• Hydrofluorocarbons (HFCs), perfluorocarbons
  (PFCs), and sulfur hexafluoride (SF6), are
  unnatural and highly effective greenhouse gases
  generated in a variety of industrial processes.

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Where Do They Come From?

• Combustion of fossil fuels to run cars and
  trucks, heat homes and businesses, and power
  factories contributes to
• 98 of U.S. carbon dioxide emissions
• 24 of methane emissions
• 18 of nitrous oxide emissions
• Methane is emitted during the production and
  transport of coal, natural gas, and oil, from the
  decomposition of organic wastes in landfills, and
  from the raising of livestock.
• Nitrous oxide is emitted during industrial and
  agricultural activities as well as the combustion
  of solid wastes and fossil fuels.

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Climate Change

• Average global surface temperature has increased
  0.5-1.0 since the end of the 19th century.
• The 20th centurys 10 warmest years occurred in
  the last 15 years of the century, 1998 being the
  warmest.
• Snow cover in the northern hemisphere and
  floating ice in the Arctic Ocean have decreased.
• Globally, sea level has risen 4-8 inches over the
  last century

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Future Predictions

• Increasing concentrations of greenhouse gases are
  likely to accelerate the rate of climate change.
• Scientists believe average global surface
  temperatures could rise by 2.2-10F in the next
  century.
• Evaporation will increase in the next century,
  increasing average global precipitation. Also,
  Intense rainstorms are likely to become more
  frequent.
• Sea level is likely to rise two feet along most
  of the U.S coast.

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