2. What Is Carbon?
An element
The basis of life of earth
Found in rocks, oceans, atmosphere
3. Carbon Pools
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Pool Amount in Billions of Metric Tons
Atmosphere 578 (as of 1700) - 766 (a s of 1999)
Terrestrial Plants 540 to 610
Soil Organic matter 1500 to 1600
Ocean 38,000 to 40,000
Fossil Fuel Deposits 4000
Marine Sediments and Sedimentary Rocks 66,000,000 to 100,000,000
Carbon is stored on our planet in the following major pools:
• as organic molecules in living and dead organisms found in the
biosphere;
• as the gas carbon dioxide in the atmosphere;
• as organic matter in soils;
• in the lithosphere as fossil fuels and sedimentary rock deposits
such as limestone, dolomite and chalk;
• in the oceans as dissolved atmospheric carbon dioxide and as
calcium carbonate shells in marine organisms.
4. Processes that transfer carbon
Between earth systems
- Photosynthesis
- Respiration
- Consumption
- Decomposition
- Combustion (Burning)
- Weathering (rocks break down and release carbon)
- Dissolve/Vaporize (Between ocean and
atmosphere)
5. Carbon Cycle Diagram
Carbon in Atmosphere
Plants use
carbon to make
food
Animals eat
plants and
take in carbon
Plants and
animals die
Decomposers
break down dead
things, releasing
carbon to
atmosphere and
soil
Bodies not
decomposed —
after many
years, become
part of oil or coal
deposits
Fossil fuels are
burned; carbon
is returned to
atmosphere
Carbon slowly
released from
these substances
returns to
atmosphere
6. Carbon Cycle
The same carbon atoms are used repeatedly on earth.
They cycle between the earth and the atmosphere.
7. Plants Use Carbon Dioxide
Plants pull carbon dioxide from the atmosphere and use
it to make food –— photosynthesis.
The carbon becomes part of the plant (stored food).
8. Animals Eat Plants
When organisms eat plants, they take in the carbon and
some of it becomes part of their own bodies.
9. Plants and Animal Die
When plants and animals die, most of their bodies are
decomposed and carbon atoms are returned to the
atmosphere.
Some are not decomposed fully and end up in deposits
underground (oil, coal, etc.).
10. Carbon Slowly Returns to Atmosphere
Carbon in rocks and underground deposits is released
very slowly into the atmosphere.
This process takes many years.
12. Carbon in Oceans
Additional carbon is stored in the ocean.
Many animals pull carbon from water to use in
shells, etc.
Animals die and carbon substances are
deposited at the bottom of the ocean.
Oceans contain earth’s largest store of carbon.
14. Human Impact
Fossil fuels release carbon stores very slowly
Burning anything releases more carbon into atmosphere
— especially fossil fuels
Increased carbon dioxide in atmosphere increases global
warming
Fewer plants mean less CO2 removed from atmosphere
