The Carbon Cycle

What is the CARBON CYCLE? the cycling of carbon between its different stores (ocean, land, lithosphere, atmosphere) - carbon is one of the most chemically versatile elements - present in all life forms - can be found organically (biomass) or inorganically (fossil fuels) carbon compounds can be very important - carbon dioxide (keeps the earth warm) - methane (greenhouse gas) - limestone - hydrocarbons (fossil fuels) - molecules (DNA)

What are the ORIGINS of carbon on Earth? - interior of the Earth (from within the mantle - semi-molten layer) - plate boundaries (from mantle. Moves up through due to volcanic eruptions) - stores such as biomass and oeans - carbon removal (atmosphere/photosynthesis/when locked up in sedimentary rocks) Carbon Stores LITHOSPHERE - crust and upper mantle - inorganic form (fossil fuels and limestone) - also organic form in humic substances (decaying matter) stores...    - peat    - fossil fuels    - soil    - marine sediments (sedimentary rocks) HYDROSPHERE - oceans - dissolved carbon dioxide - organisms like fish and plankton and some plants stores...    - surface level    - intermediate layer    - living organic matter BIOSPHERE living part  - animals - peat - living vegetation - soil humus - plant litter ATMOSPHERE - carbon dioxide as a gas (control's Earth's temperature) - atmospheric carbon dioxide is increasing (Mauna Loa Curve) - caused by human activities releasing carbon dioxide into the atmosphere    

How does carbon MOVE BETWEEN STORES? - human processes - geological components - photosynthesis - decomposition - oceanic carbon pumps - combustion - volcanic activity

What is a CARBON SINK? store that takes in more carbon than it releases What is a CARBON STORE? releases more carbon than it takes in

Geological components The rock cycle    - volcanic activity    - subduction at plate boundaries    - burial    - weathering    - formation of limestone due to the formation of carbonic acid         - sedimentary rock that contains limestone. Through plate subduction, the limestone is melted and released through volcanic activity and the carbon dioxide is released into the atmosphere. Photosynthesis - formation of glucose by plants - uses carbon dioxide Respiration - releases energy from glucose - also produces carbon dioxide Decomposition - recycles carbon into soil by deceomposers Oceanic Carbon Pumps - to do with oceanic circulation of warmer or colder currents (deeper) - cools when in contact with ice and sinks (denser) - transfers carbon dioxide from warmer currents to colder currents Combustion - releases carbon dioxide from organic material when burnt Volcanic eruptions - CO2 is stored in the mantle  Human Activity - extraction of hydrocarbons - farming practices - deforestation - consumption of fossil fuels - urban growth

Carbon Sequestration - carbon dioxide is captured from the atmosphere and held in long term storage - helps prevent global warming - geological sequestration (within rocks) - terrestial (within trees and plants)  

What are the effects of the CHANGING CARBON BUDGET? (GLOBAL WARMING) - effects on land are unclear as it hasn't been studied for long enough Oceans - sea level rise - melting sea ice - acidification (removes carbonate ions - less alkaline - coral bleaching) - salinity is reduced - cloudy water - increase in phytoplankton - less sunlight reaching plants