The Carbon Cycle _ Changes in Atmospheric Carbon by hedongchenchen

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									The Carbon Cycle &
Changes in Atmospheric
Carbon Dioxide

IB Biology – Topic 5.2
Carbon
 Crucial element to living organisms
 The term organic implies that carbon must be
  present
      Life on Earth is referred to as carbon-based life
 Where is carbon found?
      Carbohydrates, lipids, proteins, vitamins
      In the atmosphere (CO2)
      Lithosphere (rocks)
          Carbonates, fossil fuel

          Petroleum
               Gasoline, kerosene, plastics
Carbon is constantly recycled

 Photosynthesis
      Plants take CO2 in
      These producers are eaten by consumers,
       which use the carbon In their bodies
 Cellular respiration
      All trophic levels & decomposers produce
       CO2 which is released back into the
       atmosphere
         Even   plants
Other sources of carbon
dioxide
 Humans!
    Burning wood or non-renewable resources
       Petroleum products

 Volcanic activity
 Marine organisms can take carbon out of the
  water to make their shells
      Shells accumulate as sediments at the bottom of
       the ocean
      Trap carbon for millions of years in limestone
      Limestone is one of the main ingredients for
       cement
      Making cement  carbon is released as CO2
The Carbon Cycle
Changes …

 Ever since the industrial revolution
  (1800s), humans have produced
  increasing quantities of carbon dioxide
      Machines
      Factories
      Transportation
      Deforestation
      Burning wood (cooking, heating)
           all comes down to burning fossil fuels (coal
         It
          and oil)
                Rising CO2 levels
                                                    NASA data on CO2 levels
 Over the decades,                    375

  human pollution has                  370
                                       365
  produced enough                      360
  CO2 to raise its                     355
                            CO   2
  percentage in the    concentration
                          / ppm
                                       350
                                       345
  atmosphere                           340
                                       335
 Some suggest levels                  330
  have increased by                    325

  about 25%                            320
                                             1970




                                                    1975




                                                           1980




                                                                  1985




                                                                         1990



                                                                                1995




                                                                                       2000
  compared to pre-
  industrial revolution
  levels
Why do CO2 levels fluctuate?
 Plants, phytoplankton, and
  photosynthetic bacteria are more active
  in the summer months
     Think about Chicago in the winter … do
      you see a lot of green?
 Therefore, more CO2 is taken out of the
  atmosphere during the summer months
 According to NASA data (previous slide),
  there has been a 19.4 % increase in the
  mean annual concentration of CO2 over
  the past 47 years.

								
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