Carbon Cycle

Carbon CycleThe carbon cycle is the circulation and transformation of carbon back and forth between living things and the environment.1What Is Carbon?

2Importance of CarbonBuilding block of life

Fixed amount

CO2 is only of the atmosphere (0.04%)

Energy balance of the planet

Protective blanket

Organic CarbonHydrocarbons: CH4

Carbohydrate: CH2O

Inorganic carbonCarbon Dioxide: CO2

Calcium Carbonate: CaCO3

Mandale Limestone Quarry

Carbon Carbon exists in the nonliving environment as:

Carbon dioxide (CO2)Carbonic acid ( HCO3-)Carbonate rocks (limestone and corals = CaCO3) Deposits of Fossil fuelsDead organic matter

Carbon reservoirsThe atmosphere (carbon dioxide)

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) Carbon reservoirs

Parts of the Earth system where carbon is stored is called carbon reservoirs

8Carbon in OceansAdditional 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 earths largest store of carbon.9Carbon CycleThe same carbon atoms are used repeatedly on earth. They cycle between the earth and the atmosphere.

10Plants Use Carbon DioxidePlants pull carbon dioxide from the atmosphere and use it to make food photosynthesis.The carbon becomes part of the plant (stored food).

11PhotosynthesisCO2 + H2O + sunlight CH2O + O2

Carbon is taken from the atmosphere in several waysPhotosynthesis. 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. Animals Eat PlantsWhen organisms eat plants, they take in the carbon and some of it becomes part of their own bodies.

14Plants and Animal DieWhen 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.).

15Carbon Slowly Returns to AtmosphereCarbon in rocks and underground deposits is released very slowly into the atmosphere.

This process takes many years.16Carbon is released into the atmosphere in several waysRespiration 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 metamorphismThrough 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.

17Respiration CH2O + O2 CO2 + H2O + energy

Combustion or Oxidization of hydrocarbon

CH4 + 2 O2 CO2 + 2 H2O + energyCarbon Cycle DiagramCarbon in AtmospherePlants use carbon to make foodAnimals eat plants and take in carbonPlants and animals dieDecomposers break down dead things, releasing carbon to atmosphere andsoilBodies not decomposed after many years, become part of oil or coal depositsFossil fuels are burned; carbon is returned to atmosphereCarbon slowly released from these substances returns to atmosphere20The Carbon Cycle

21

Human ImpactFossil fuels release carbon stores very slowly

Burning anything releases more carbon into atmosphere especially fossil fuels

25Fossil FuelsPetroleumNatural GasCoal

Fossil Fuel86% of global primary energy consumption is fossil fuels.

27Human Impacts on the Carbon CycleBurning fossil fuels have serious impact on the carbon cycle.

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 worlds 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.

29Green House Effect-Global WarmingIncreased carbon dioxide in atmosphere increases global warming

Result

What We Need to DoBurn less, especially fossil fuels

Promote plant life, especially trees

Fewer plants mean less CO2 removed from atmosphere

32Safe/Green Energy alternatives

Thanks for your attention!