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
What is the carbon budget
The difference between the inputs and outputs of carbon into a system
Balance of inputs / outputs into a subsystem determines whether it acts as a source or sink
How does atmosphere and climate impact the carbon cycle
Carbon cycle affects the amount of gases containing carbon in the atmosphere
Greenhouse gases trap some of the suns energy - keep some of heat in and keep planet warm
As concentrations of GG increase - temperatures expected to rise - global warming
Changes in temperature across globe will affect other aspects of climate e.g. storms will become more intense
How does land impact the carbon cycle
Carbon cycle allows plant growth (photosynthesis) ➡️also no decomposition and so dead plants would remain where they fell and nutrients would not be recycled
Changes in carbon cycle can ⬇️ amount of carbon ststored in land
E.g. ⬆️temps ➡️permafrost melt ➡️ ⬆️carbon inatmosphere
⬆️Global temps = ⬆️frequency of wildfires
How do oceans impact the carbon cycle
CO2 dissolved directly into oceans from atmosphere
CO2 used by phytoplankton and seaweed (photosynthesis) and to form calcium carbonate shells
⬆️ in CO2 = ⬆️ acidity of oceans - initially absorb more CO2 ➡️ adverse affects on marine life
How can global warming affect oceans?
Organisms sensitive to temperature (e.g. phytoplankton)
Can’t withstand higher temps
Numbers ⬇️ - ⬇️ CO2 used by them for photosynthesis
⬇️ carbon removed from atmosphere
How much more CO2 is in atmosphere than in 1750
40%
What is IPCC
Intergovernmental Panel on Climate Change
Set up by UN to share knowledge of climate change
How can individuals mitigate impacts of climate change
Use cars less and buy more fuel efficient cars
Make homes more energy efficient
How can regions and nations mitigate impacts of climate change
Reduce reliance of FF for heating and powering home
⬆️ availability and ⬇️ cost of renewable energy sources
Afforestation and restoring degraded forests - ⬆️ uptake
Planners cam ⬆️ sustainability of places - public transport/ green spaces
CCS
How can the globe mitigate impacts of climate change
Countries work together to reduce emissions
Kyoto protocol (1997) and Paris (2015)
International carbon trading schemes - credits
What is the natural greenhouse effect
Gases prevent some energy escaping into space and reflect back to earth. This means temps on earth higher than they otherwise would be
What is the EGE
When additional GGs reflect more energy back to earth than natural greenhouse effect - ⬆️temps even further
Human activities are ⬆️ conc of GGs in atmosphere
Thought to be cause of global warming
Positive feedback water cycle
Temps ⬆️
Evaporation ⬆️
⬆️ amount of water vapour in atmosphere
Greenhouse effect ⬆️
Negative feedback water cycle
Temps ⬆️ Evaporation ⬆️ Water vapour in atmosphere ⬆️ ⬆️cloud cover reflects more of suns energy Temps ⬇️
Positive feedback carbon cycle
Temps ⬆️
Plant respiration rate ⬆️
Amount of CO2 in atmosphere ⬆️
Greenhouse effect ⬆️
Negative feedback carbon cycle
CO2 in atmosphere ⬆️
Plant growth ⬆️
Plants remove and store ⬆️ CO2
CO2 in atmosphere ⬇️
