Carbon Cycle

Carbon

• Carbonic acid ( HCO3−)

• Carbonate rocks (limestone and coral = CaCO3)

• Deposits of Fossil fuels

Carbon exists in the nonliving environment as:

Organic Carbon

• Hydrocarbons: CH4

• Carbohydrate: CH2O

Inorganic carbon

• Carbon Dioxide: CO2

• Calcium Carbonate: CaCO3

Mandale Limestone Quarry

Carbon Reservoirs

Carbon reservoirs•The atmosphere -as carbon dioxide

•The biosphere - as organic carbon (include fresh water systems and non-living organic material, such as soil carbon).

•The oceans - as dissolved carbon dioxide and molecules like calcium carbonate ( including dissolved inorganic carbon and living and non-living marine biota).

•The lithosphere as sedimentary rock like limestone and metamorphic rock like marble (sediments, Earth core including fossil fuels).

Carbon Cycle

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 made from limestone

•The ocean releases CO2 by diffusion into the atmosphere.

•Volcanic eruptions and metamorphism

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 organic molecules, or carbonates.

Photosynthesis sunlight

6CO2 + 12H2O + ---------->C6H12O6 + 6 O2

Chlorophyll

Respiration

C6H12O6 + 6O2 --> 6CO2 + 6H2O + usable energy(ATP)

Combustion or Oxidization of hydrocarbon

CH4 + 2 O2 --> CO2 + 2 H2O + energy

Human Impacts on the Carbon Cycle

The burning of fossil fuels has a serious impact on the carbon cycle.

Fossil Fuel

86% of global primary energy consumption is fossil fuels.

Fossil Fuels

• Petroleum

• Natural Gas

• Coal

CO2 Concentration

Pre-Industrial value: 280 ppm (600 billion tons)Current value: 400 ppm (840 billion tons)Critical value: 560 ppm (1200 billion tons)

Keeling Curve

Question: Why does line of the curve go up and down by about 5 ppmv instead of in a straight line?

What process is occurring at each number?

Photosynthesis

Animal Respiration

Decay of animal wastes

Decay of plant litter

Plant Respiration

Carbon Cycle Summary

ProcessProcess Organism Organism C changed C changed from from

C changed C changed toto

Photosynthesis

Respiration

Decomposition

Combustion

Dissolution (Dissolved)

Lithification

Eruptionof volcanos

Green Plants,Algae, some

bacteriaCO2 C6H12O6

All organisms C6H12O6 CO2

Decay bacteria,Fungi

Organic Carbon

CO2

N/ABurning

Organic Carbon

CO2

N/AIn water

CO2Carbonic

acid

N/AForming rocks

Plant and animal remains

Fossil fuels

CaCO3Calcium

carbonate

Limestone,Marble

Limestone,Marble CO2

N/AGas from volcanos

Part II: The Carbon Reservoirs

On a global scale , carbon moves between four major reservoirs (also called carbon

sinks). These reservoirs include ______________________,

______________________,______________________, and

__________________________.

Which reservoir contains the most carbon? _______________.

Atmosphere

Biosphere

Lithosphere

Ocean

Lithosphere

Part III: The Biological (Biotic) Processes

1. Photosynthesis is a process that takes place in organisms containing pigments

capable of capturing the energy of light. The main photosynthetic pigment is the green

pigment called chlorophyll found in green plants, algae, and Cyanobacteria. Organisms

with this pigment are able to remove ___________________________ from the

atmosphere and combine it with ________________ in the presence of chlorophyll and

sunlight making ____________________ (energy storage molecules) and releasing the

gas _________________ to the atmosphere.

Complete the generalized equation:Sunlight________ + ________ --------------------> ________ + ________ Chlorophyll

Carbon dioxide

Water

Glucose

Oxygen

6 CO2

12 H2O

C6H

12O

6 6 O2

2. Cellular respiration is a process that takes place in cells that releases the chemical

energy stored in larger molecules to be restored in small molecules that cells can use.

The process takes the larger energy storage molecule called __________________

and combines it with __________________ from the atmosphere. This releases the

chemical energy that is captured by the small energy molecules called ____________

that can be used by cells. End products of cellular respiration are _______________

and _________________ which is released into the atmosphere.

Complete the generalized equation:

__________ + __________ --------------------> _________ + __________ + __________

Glucose

Oxygen

ATP

carbon dioxide

water

C6H

12O

6 6 O2

6 CO2

6 H2O

ATP

Part IV: The Inorganic (abiotic) Processes

1.The burning of any organic matter form fossil fuels to forests rapidly releases the

carbon stored in its molecules as the gas _______________________ to the

atmosphere.

2. Carbon as the gas _____________________ readily dissolves into bodies of water

from ponds to oceans. This gas readily combines with water molecules to form an acid

called _______________________ often lowering the pH of the water.

Carbon dioxide

Carbon dioxide

Carbonic Acid

3. Aquatic organisms that protect themselves with shells combine the gas

_____________________ with the mineral calcium making _____________________, the material that forms its shell. When these shelled organisms died, their shells rain

down to the bottom of the lake or ocean collecting in deep layers as sediment. Slowly,

the shells are compressed into sedimentary rock in a process called

_________________________

4. Over geologic time, sedimentary and metamorphic rock containing carbon are

subducted, melted and rise toward the surface of the earth as magma and gases

like _________________________ which are released into the atmosphere when

volcanos ______________________.

Carbon dioxide Calcium carbonate

Limestone

Erupt

Carbon dioxide