1. The Cycling of Matter

2. Why Learn About This?
Most minerals essential for life cycle between living things and the atmosphere or the ground
Atmosphere—gases surrounding Earth
Biosphere—living ‘layer’ of Earth
Lithosphere—soil/rock layer of Earth
Hydrosphere—water parts of Earth
Earth is a “closed” ecosystem
The only thing in is sun (energy), the only thing out is some heat(energy)
Energy ‘flows through’, but matter ‘cycles within’

3. Carbon Cycle

4. Carbon Carbon exists in the nonliving environment as:
Carbon dioxide (CO2)
Carbonic acid ( HCO3−)
Carbonate rocks (limestone and coral = CaCO3)
Deposits of Fossil fuels
Dead organic matter

5. Organic Carbon
Hydrocarbons: CH4
Carbohydrate: CH2O

6. Inorganic carbon Carbon Dioxide: CO2 Calcium Carbonate: CaCO3
Mandale Limestone Quarry

7. Carbon Cycle Short Term
All livings things are composed of carbon
Green plants and algae convert CO2 in the atmosphere along with water into carbohydrates.
These carbohydrates are used as a source of energy for all other organisms
CO2 is recycled when autotrophs and heterotrophs release it back into air during celllular respiration.

8. Carbon Cycle Long Term
Carbon enters a long-term cycle when organic material is buried underground and converted to peat, oil, coal or gas.
This can take millions of years
Carbon is released when fossil fuels are burned
Carbon can also enter in a long term cycle in the form of calcium carbonate (found in shells of marine animals) when they fall to the ocean floor and create vast deposits of limestone rock. Carbon is released due to weathering and erosion

9. Carbon Cycle

10. Carbon reservoirs
Parts of the Earth system where carbon is stored is called carbon reservoirs

11. Carbon reservoirs The atmosphere.
The biosphere (include fresh water systems and non-living organic material, such as soil carbon).
The oceans ( including dissolved inorganic carbon and living and non-living marine biota).
The lithosphere (sediments, Earth core including fossil fuels).

12. Carbon Cycle
The movement of carbon, in its many forms, between the biosphere, atmosphere, oceans, and geosphere is described by the carbon cycle.

13. Carbon is released into the atmosphere in several ways
Respiration by plants and animals.
Decay of animal and plant matter.
Combustion of organic material
Production of cement.
The ocean releases CO2 into the atmosphere.
Volcanic eruptions and metamorphism
Through the respiration performed by plants and animals.
Through the decay of animal and plant matter.
Through combustion of organic material which oxidizes the carbon it contains.
Production of cement.
At the surface of the oceans where the water becomes warmer, dissolved carbon dioxide is released back into the atmosphere.
Volcanic eruptions and metamorphism release gases into the atmosphere.

14. Carbon is taken from the atmosphere in several ways
Photosynthesis.
The oceans when the seawater becomes cooler, more CO2 dissolve and become carbonic acid.
In the upper ocean areas organisms convert reduced carbon to tissues, or carbonates.

15. Photosynthesis
CO2 + H2O + sunlight  CH2O + O2

16. Respiration
CH2O + O2  CO2 + H2O + energy

17. Combustion or Oxidization of hydrocarbon
CH4 + 2 O2  CO H2O + energy

18. Human Impacts on the Carbon Cycle
Burning fossil fuels have serious impact on the carbon cycle.

19. Fossil Fuel
86% of global primary energy consumption is fossil fuels.

20. Fossil Fuels
Petroleum
Natural Gas
Coal

21. CO2 Concentration Pre-Industrial value: 280 ppm (600 billion tons)
Current value: 380 ppm (800 billion tons)
Critical value: 560 ppm (1200 billion tons)

22. Keeling Curve
The Keeling Curve shows a cyclic variation of about 5 ppmv in each year corresponding to the seasonal change in uptake of CO2 . How can you explain this ?
Most of our world’s vegetation is in the Northern hemisphere, since this is where most of the land is located. During winter in the northern hemisphere, photosynthesis ceases when many plants lose their leaves, but respiration continues. This condition leads to an increase in atmospheric CO2 concentrations during the northern hemisphere winter. With the onset of spring, however, photosynthesis resumes and plants start to intake the CO2, therefore the atmospheric CO2 concentrations are reduced.