Sequence of processes through which carbonSequence of processes through which carbon compoundsSequence of processes through which carbon compounds move from one carbon reservoirSequence of processes through which carbon compounds move from one carbon reservoir or sink (such as forests and oceans) to another (such as atmosphere) and back.
Since more carbon dioxide is being released into the atmosphere through the burning of fossil fuelsSince more carbon dioxide is being released into the atmosphere through the burning of fossil fuels and less is being 'fixed' (converted into organicSince more carbon dioxide is being released into the atmosphere through the burning of fossil fuels and less is being 'fixed' (converted into organic compounds through photosynthesisSince more carbon dioxide is being released into the atmosphere through the burning of fossil fuels and less is being 'fixed' (converted into organic compounds through photosynthesis by plants) because of the destructionSince more carbon dioxide is being released into the atmosphere through the burning of fossil fuels and less is being 'fixed' (converted into organic compounds through photosynthesis by plants) because of the destruction of tropical forests, the carbon cycle is in danger or being severely disrupted.
International accords such as Kyoto protocolInternational accords such as Kyoto protocol are trying to limit the productionInternational accords such as Kyoto protocol are trying to limit the production of carbon dioxide (and other greenhouse gasesInternational accords such as Kyoto protocol are trying to limit the production of carbon dioxide (and other greenhouse gases) through the imposition of emissionInternational accords such as Kyoto protocol are trying to limit the production of carbon dioxide (and other greenhouse gases) through the imposition of emission controls.
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The concentration of carbon in living matter (18%) is almost 100 times greater than its concentration in the earth (0.19%). So living things extract carbon from their nonliving environment. For life to continue, this carbon must be recycled.
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Carbon exists in the nonliving environment as:
Carbon dioxide (CO2) in the atmosphere and dissolved in water (forming HCO3−) .
Carbonate rocks (limestone and coral = CaCO3) .
Deposits of coal, petroleum, and natural gas derived from once-living things
Dead organic matter, e.g., humus in the soil.
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Carbon enters the biotic world through the action of autotrophs:
Primarily photoautotrophs, like plants and algae, that use the energy of light to convert carbon dioxide to organic matter.
To a small extent, chemoautotrophs — bacteria and archaea that do the same but use the energy derived from an oxidation of molecules in their substrate.
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Carbon returns to the atmosphere and water by :
Respiration (as CO2)
Burning
Decay (producing CO2 if oxygen is present, methane (CH4) if it is not.