1. The Carbon Cycle
The movement of carbon between the 4 “spheres” of earth: biosphere, atmosphere, hydrosphere and geosphere
(“sphere” means “area”)
The amount of carbon on earth does not change. The carbon just moves from one place to another.

2. Biosphere
“Bio” = life
The area of the earth that contains living organisms (plants and animals).

3. Atmosphere “Atmos” = vapor (gas)
The area of the earth that is gaseous (made of gas). The air around us.

4. Hydrosphere “Hydro” = water The area of the earth that are water:
Oceans
Lakes
Rivers

5. Geosphere (Lithosphere)
“Geo” and “lithos” = rock
The area of the earth that are solid (made of rock)

6. Where is Carbon in our Environment?
CO2 in the atmosphere
CO2 dissolved in water
Carbonate rocks (example: limestone)
Deposits of coal, petroleum and natural gas (fossil fuels)
Living organisms (plants and animals)
Dead organic matter (found in soil)
** CO2 = Carbon Dioxide

7. The White Cliffs of Dover (England):
Carbonate rocks made from the remains of sea creature shells

8. Review! What are the 4 “spheres” in the carbon cycle?
What do each of the “spheres” represent?

9. Carbon Sink or Source?
CARBON SINK = Anything that takes CO2 out of the atmosphere
CARBON SOURCE = Anything that puts CO2 into the atmosphere

10. Review 6 1
Click on Arrows 1-6 3 2 4 5

11. (Carbon Sink) Carbon moves from the atmosphere to plants.
Photosynthesis
(Carbon Sink) Carbon moves from the atmosphere to plants.
Carbon dioxide (CO2) is pulled out of the air and the carbon is used by plants to grow.
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12. “Organic” (Living) Carbon
(Neutral: not a sink or source) Carbon moves from plants to animals.
Carbon in plants moves to animals that eat them.
Animals that eat other animals get carbon from their food, too.
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13. (Carbon Sink) Carbon moves from plants and animals to the ground
Death and Burial
(Carbon Sink) Carbon moves from plants and animals to the ground
Plants and animals die and decay putting carbon into the ground.
Some get buried very deep and will become fossil fuels in millions and millions of years.
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14. (Carbon Source) Carbon moves from living things to the atmosphere.
Respiration
(Carbon Source) Carbon moves from living things to the atmosphere.
All living things produce carbon dioxide (CO2).
Animals and plants get rid of carbon dioxide gas through a process called respiration (breathing).
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15. Burning Fossil Fuels
(Carbon Source) Carbon moves from fossil fuels to the atmosphere when they are burned.
When we burn fossil fuels, carbon enters the atmosphere as CO2. Each year, 5.5 billion tons of carbon is released by burning fossil fuels.
(That’s the weight of 100 million elephants!)
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16. (Carbon Sink) Carbon moves from the atmosphere to the oceans.
Ocean Uptake
(Carbon Sink) Carbon moves from the atmosphere to the oceans.
The oceans soak up (dissolve) some carbon dioxide from the atmosphere.
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17. Review!!
What is a carbon sink?
What is a carbon source?

18. Sink or source (or neutral)?
Carbon dissolving in the ocean
Volcano erupting and giving off CO2 gas
Burning fuels like coal and natural gas
Photosynthesis
Respiration

19. Fossil Fuels When fossil fuels form are they a source or a sink?
When we use fossil fuels for energy are they a source or a sink?