The Global Carbon Cycle Flashcards
Name 5 processes that transfer carbon
- Photosynthesis
- Respiration
- Decomposition
- Burning fossil fuels
- Carbon sequestration
What can the global carbon cycle be subdivided into?
- Geosphere
- Biosphere
What is the Geosphere carbon cycle?
Operates at slow rate of thousands to millions of years
What is the Biosphere carbon cycle?
Operates at fast rate of seconds to hundreds of years
How is carbon stored in the atmosphere?
- CO² and Methane
- 766 billion metric tons
How is carbon stored in the biosphere?
- Organic molecules in living and dead plants and animals
- Soil as organic matter from dead plant material and activity of microorganisms
- Decay process releases CO² into atmosphere
- Plants: 610 billion metric tons, Soil: 1600 billion metric tons
How is carbon stored in the oceans?
- Dissolved CO² in water
- Calcium carbonate in shells of marine life, fall to sea floor becoming marine sediments
- Located at great depths, 4% found at surface
- 40,000 billion metric tons
How is carbon stored in the lithosphere?
- Fossil fuels (Coal, oil and gas)
- Sedimentary rock e.g. Limestone and chalk
- Largest store of carbon (100,000 billion metric tons)
What is the carbon balance?
- Carbon reservoirs acts as both sources (Add carbon to atmosphere) and sinks (Removing carbon from atmosphere)
- All sources and sinks are equal then carbon cycle is in balance
What are fluxes?
- Movement of carbon between different reservoirs
- Each flux is a chemical reaction or physical process
- Each flux take carbon out of one store and put it in another e.g. Photosynthesis
Give an example of carbon flow from the Atmosphere to Biosphere
Plants use CO² in process of photosynthesis and carbon is locked in plant material, passed along food chain to herbivores and later carnivores (Biological pump in oceans)
Give an example of carbon flow from the Biosphere to Atmosphere
Released as CO² by plant and animal organisms through respiration
Give an example of carbon flow from the Atmosphere to Ocean
CO² gradually diffuses into oceanic waters
Give an example of carbon flow from the Ocean to Lithosphere
Coral and shelled organisms die, calcium carbonate sinks to bottom of ocean, over millions of years compressed into sedimentary rock
Give an example of carbon flow from the Lithosphere to Atmosphere
Carbon stored in lithosphere released during volcanic eruptions
Outline the ‘slow carbon cycle’
- Takes millions of years
- Carbon stored in sedimentary rock
- CO² released from sedimentary deposits through weathering and volcanic activity
Outline the ‘fast carbon cycle’
- Takes place within lifetime
- Movement of carbon through food chains
- Photosynthesis absorbs carbon in minutes, respiration releases carbon in seconds
Give 4 facts on the global carbon cycle
- Produce 30 gigatons of CO², atmosphere can only absorb 40% = 18 gigaton excess
- 80% carbon locked up in rocks
- Ocean absorbs 1/4 of anthropogenic carbon
- CO² absorbed by ocean through diffusion and stored as carbonic acid
How have humans affected the carbon cycle?
- Use of coal, oil, gas and cement grown exponentially after WW2
- Land use change and exhaustion of fossil fuels largest impacts
- 90% anthropogenic carbon from combustion of fossil fuels
Where does carbon on Earth come from?
1) Explosion of supernova
2) Reactions occur - 2 Helium = Beryllium, Beryllium + Helium = Carbon
3) Carbon heavy element, conglomerates together - Dragged to centre of solar system, Earth is largely carbon based (Central planet)
What is carbon sequestration?
Process by which CO² is either removed from atmosphere or diverted from emission sources and stored in ocean, terrestrial environments and geological formations
Give a danger associated with artificial sequestration
CO² deposits leak, gas could harm humans and environment
Give the formula for photosynthesis
Carbon dioxide + Water GOES TO Glucose + Oxygen
