The Carbon Cycle On Earth Flashcards
What are the major stores of carbon?
- lithosphere = 99.9% stores in sedimentary rock, stored in fossil fuels
- atmosphere = co2 and methane
- hydrosphere = co2 dissolved in rivers, lakes and oceans
- biosphere = stored in tissue of living organisms —> transferred to soil when organisms die and decay
- cryosphere = permafrost, decomposing plants and animals have frozen into the ground
What is carbon?
- found both in organic and in organic stores
- mainly stores in the mantle
- closed system
Carbon sink
A store that absorbs more carbon than it releases
Carbon source
A store that releases more carbon than it absorbs
Carbon transfer
Transfers carbon between stores
Driving changes in the carbon cycles stores (FLOWS + TRANSFERS)
- Photosynthesis
- respiration
- decomposition
- combustion
- carbon sequestration (oceans and sediments_
- weathering
Photosynthesis (FLOW + TRANSFER)
- transfers carbon stores in the atmosphere to the biomass
- fast
- plants an phytoplankton use energy from the sub to change co2 and water into glucose and oxygen
Respiration (FLOW + TRANSFER)
- transfers carbon from living organisms to the atmosphere
- plants and animal streak down glucose = energy and release co2 and methane
Decomposition (FLOW + TRANSFER)
- transfers carbon from dead biomass to the atmosphere and soil
- fungi and bacteria break down organisms
- fast
Combustion (FLOW + TRANSFER)
- Transfers carbon stores in living, dead or decomposed biomass to the atmosphere through burning
- wildfires cause carbon flow
- fast
Carbon sequestration (FLOW + TRANSFER)
- carbon from the atmosphere can be sequestrated (captures and held) in sedimentary rock or as a focal fuel
- form over millions of years wage dead animals and plants fall to ocean floor = then compared
- carbon in fossil fuels is released when burnt
Weathering (FLOW + TRANSFER)
- chemical weathering transfers carbon from the atmosphere to the hydrosphere and biosphere
- atmospheric carbon = reacts with water vapour to form acid rain = when rain falls it reacts with rocks and dissolves them
What are the scales of carbon stores?
- local scale = trees a Bros rising co2, leaf litter decomposing
- sere scale = deciduous wood, hydrosphere —> water/pond
- continental = co2 removed by dissolving in water to form carbon acid
What are the physical factor affecting the carbon cycle?
- wildfires
- volcanic activity
Physical factors - wildfires
- rapidly transfer large quantities of carbo from biomass to the atmosphere
- loss of vegetation = decreases photosynthesis —> less carbon removed from the atmosphere
- longer term can encourage plant growth
Physical factors - volcanic activity
- carbon stores within the earth in magma is released during volcanic eruptions
- between 130-180 mill tones of co2 is released into the atmosphere each year c
Human factors affecting the carbon cycle
- fossil fuel extraction and use
- deforestation
- farming practices
- land use changes
Human factor - fossil fuel extraction and use
- extracting and burning fossil fuels releases co2
- without human intervention = co2 would remain sequestrated in the lithosphere
Human factor - deforestation
- forests cleared for agriculture, logging or new developments
- clearance reduces the size of carbon store
Human factor - farming practices
- animals release co2 and methane when they respire and digest food
- ploughing releases co2 stores in soil
- mechanisation of farming practices also increases co2 emissions
Human factors - land use changes
- natural or agricultural land changed to urban
- vegetation removed = reduces carbon storage in biosphere
- concrete production release co2
Carbon budget
- difference between he inputs and outputs of carbon into a subsystem and outputs of carbon from it
- the balance of inputs and outputs determines wither it is a carbon source or sink
