Carbon Cycle

Carbon Cycle

• Organic = plants and animals
• Inorganic = fossil fuels - oil, coal

Compounds

• CO2 - Greenhouse gas - climate change
• CH4 - methane
• CaCO3 - limestone / Calcium Carbonate
• Hydrocarbons - fossil fuels
• Biomolecules - proteins, DNA etc

Origins of Carbon

• Earth's interior - originate in mantle. Transferred to crust via plate margins. Volcanoes erupt Carbon
• Stores - biomass, oceans
• Carbon removal - from atmosphere via photosynthesis, sedimentary rocks

Major stores

Lithosphere

• Crust and upper mantle
• Inorganic form - fossil fuels, limestone
• Organic form - humus (decaying material) (pedosphere)
• Stores - fossil fuels, pedosphere and peat, marine sediments

Hydrosphere

• Oceans - dissolved CO2
• Organisms - fish, plankton (zoo and photo), plants
• Stores - surface (plants), intermediate (deeper water), living organic matter

Atmosphere

• CO2 - 0.04% but control Earth's temperature
• Greenhouse gas effect - anthropogenic activities, global warming

Biosphere

• Living vegetation
• Decaying plants and animal matter
• Soil humus and peat

Carbon Budget

Movements

Geological components 

• Rock cycle - weathering, burial, subduction, volcanoes
• Limestone formation - CO2 + H2O ->H2CO3 (Carbonic acid)
  • H2CO3 + Ca -> CaCO3 (Calcium Carbonate / limestone)
    • Subduction of sedimentary rock as CO2 via volcanoes

Photosynthesis, respiration and decomposition

• Photosynthesis = 6CO2 + 6H20 -> C6H12O6 +6O2
• Respiration = 6O2 + CH12O6 -> 6CO2 + 6H2O
• Decomposition - organic matter decomposed to form stable forms…