Carbon Cycle Flashcards
Where can carbon be found in the lithosphere
- 9% of carbon on earth stored in sedimentary rocks
0. 004% stored in fossil fuels in lithosphere
Where can carbon be found in the atmosphere
Stored as CO2 and methane
Contains around 0.001% of earths carbon
Where can carbon be found in the hydrosphere
CO2 dissolved in rivers / lakes / oceans
Oceans = 2nd biggest carbon store = approx 0.4% of Earths carbon
Majority deep in ocean as dissolved inorganic carbon
Small amount found at ocean surface where it is exchanged w atmosphere
Where can carbon be found in the biosphere
Stored in tissues of living organisms
Transferred when die and decay
0.004% or Earths carbon
Where can carbon be found in the cryosphere
Less than 0.01%
In the soil in permafrost where decomposed plants and animals have frozen in the ground
What type of system is the carbon cycle
Closed system
Inputs / outputs of energy change but amount of carbon the same
Main carbon stores
Atmosphere Vegetation Soils Fossil fuels Sediment Oceans Earths crust
Main carbon flows (from stores)
Respiration Burning fossil fuels Combustion Ocean loss Volcanic eruption
Main carbon flows (to stores)
Photosynthesis Sequestration Chemical rock weathering Decomposition Death
How does the amount of carbon stored by photosynthesis change over time
Atmosphere ➡️biomass
Plants & phytoplankton use energy from the sun to change CO2 and water into glucose and O2
Carbon passed through food chain and released through respiration and decomposition
How does the amount of carbon stored by respiration change over time
Living organisms ➡️ atmosphere
Glucose + o2 ➡️ CO2 + methane
How does the amount of carbon stored by combustion change over time
biomass ➡️ atmosphere by burning
Wildfires cause carbon flow
How does the amount of carbon stored by decomposition change over time
Dead biomass ➡️ atmosphere & soil
Bacteria and fungi break the organisms down- CO2 and methane released
Some carbon transferred to soil in form of humus
How does the amount of carbon stored by ocean uptake and loss change over time
CO2 dissolved directly into ocean from atmosphere
Also transferred to oceans when it is taken up by organisms
Ocean ➡️ atmosphere when carbon rich water rises and releases CO2
How does the amount of carbon stored by weathering change over time
Chemical weathering ➡️ hydro and biosphere
Atmospheric carbon reacts with water vapour to form acid rain
Dissolves the rocks - molecules washed into sea - react w dissolved CO2 to make CaCO3 - used to make shells
How does the amount of carbon stored by sequestration change over time
Carbon from atmosphere can be sequestered in sedimentary rocks or as fossil fuels
Carbon in fossil fuels is sequestered until burnt
How do carbon flows vary in time and space
FAST NON ORGAIN CARBON FLOWS- ocean ➡️ atmosphere exchange of CO2 through diffusion
FAST CARBON FLOWS- minutes / hours / days - photosynthesis, respiration , combustion
SLOW CARBON FLOWS - years and years - e.g. sequestration
SPATIAL SCALE - plant scale - respiration & photosynthesis
-ecosystem scale - + combustion and decomposition
- continental scale - all carbon flows occur
How do wildfires impact the carbon cycle
Biomass ➡️ atmosphere
Loss of veg ⬇️ photosynthesis, less carbon removed from atmosphere
Fires can encourage growth of new plants - take in CO2
Can have neutral affect on level of atmospheric carbon
Depends on amount and type of regrowth
How does volcanic activity impact the carbon cycle
Carbon stored in lithosphere as magma is released in an eruption- majority CO2
Recent ones have released less CO2 than human activities would in same amount of time
E.g. Iceland eruption 2009 = flights cancelled = neutral effect
Potential for eruption to affect cycle significantly
How does hydrocarbon extraction and use impact the carbon cycle
Extracting and burning releases CO2 into atmosphere ➡️ EGE and climate change
W/out human intervention, carbon would remain sequestered
How does deforestation impact the carbon cycle
Forests may be cleared for agriculture , logging or to make way for developments
Clearance reduces size of carbon store and, if forest burned, rapid flow of carbon from bio to atmosphere
20% of global carbon emissions
EGE and climate change
How do farming practices impact the carbon cycle
ANIMALS release CO2 and methane when respire and digest
PLOUGHING release CO2 stored in soil / machinery burns fossil fuels
GROWING RICE in paddies releases lots of methane - 20% global emissions - primary food source for 50% or population
MOST ARTIFICIAL FERTILISERS made from fossil fuels - spread then leads to leaching
How does world population affect emissions form farming practices
⬆️ world population ⬆️ food production ⬆️ carbon emissions from farming practices
How do land use changes impact the carbon cycle
Extensive ➡️ intensive farming practices = growing demand for food from growing population
Especially meat in growing China middle classes
Deforestation + planting of palm oil palms & soya plantations + conversion of forest to grassland for grazing
Urbanisation - ⬆️ area covered - removes carbon sinks
⬆️ industry and transport - ⬆️ fossil fuels
Production of cement for building releases CO2
