The Carbon Cycle Flashcards
What are all the different stores of carbon on land/air?
Carbon dioxide in the atmosphere
Carbon in plants and animals
Dead organic matter
Fossil fuels
Carbonate rocks
Methane
Where is carbon found in plants and animals?
Carbohydrates
Lipids
Proteins
How many billion tonnes of carbon are in the atmosphere?
700
How many billion tonnes of carbon is in plants?
450
How billions of tonnes of carbon is found in dead organic matter?
700
How many billion tonnes of carbon are found in fossil fuels?
10000
How many billion tonnes of carbon are found in carbonate rocks?
20,000,000
What are all the stores of carbon is the seas, oceans and rivers?
Carbon in surface layers of the sea
Carbon in plankton
Carbon in marine animals
Dead organic matter
Dissolved in deep ocean
What forms of carbon are found in the surface layers of the sea?
Carbon dioxide
Hydrogen carbonate ions
How many billions of tonnes of carbon are in the surface layers of the sea?
500
How many billions of tonnes of carbon are found in phytoplankton and marine animals?
5 each
How much billions tonnes of carbon are found in dead organic matter(ocean)?
3000
How many billion tonnes of carbon is dissolved in the deep ocean?
35000
What natural state is the carbon cycle in?
A state of dynamic equilibrium
What does dynamic equilibrium mean for the carbon cycle?
Little or no overall change in the amount of carbon in each of the reservoirs of the cycle
What are the main reservoirs in the carbon cycle?
Atmosphere
Hydrosphere
Biosphere
Lithosphere
What are the main chemical forms of carbon in the atmosphere?
Carbon dioxide
Methane
Carbon monoxide
What are the quantities of different carbon gases in the atmosphere?
CO2= 700gt
Methane= 1.2 gt
Carbon monoxide= trace
What are the main chemical forms of carbon found in the hydrosphere?
Hydrogen carbonate ions
Dissolved carbon dioxide
What are the quantities of carbon in the hydrosphere?
Surface waters 500Gt
Deep ocean 35000Gt
What are the main chemical forms of carbon in the biosphere? (C P L)
Carbohydrates- cellulose, lignin, starch, sugars
Proteins
Lipids- vegetable oils, animal fats
What is the quantity of carbon in the biosphere?
Living organisms 470 Gt
Dead organic matter 3700 Gt
What are the main chemical forms of carbon in the lithosphere?
Carbonaceous rock- limestone, calcium carbonate
Fossil fuels- carbon and hydrocarbons
What are the quantities of carbon in the lithosphere?
Sedimentary carbonates- 20,000,000 Gt
Fossil fuels- 10,000 Gt
How does photosynthesis affect the carbon cycle?
Photosynthesis converts low-energy substances like CO2 and water into high energy carbohydrates that might be converted into proteins and lipids which is stored in the tree
How does respiration affect the carbon cycle?
Aerobic respiration returns carbon to the atmosphere as CO2
Anaerobic respiration returns carbon to the atmosphere as methane
How do food webs affect the carbon cycle?
Some carbohydrates, proteins and lipids from plants are eaten by herbivores which may be eaten by carnivores. (defecation and break down or left waste of faeces)
How does fossilisation affect the carbon cycle?
Incomplete decomposition of DOM usually anaerobic can produce long term carbon stores (fossil fuels)
Some organisms (corals, molluscs and planktonic) have calcium carbonate exoskeletons may produce limestone which is the carbon store in the lithosphere
How does combustion affect the carbon cycle?
Burning of organic materials releases carbon dioxide
How does deforestation affect the carbon cycle?
Reduces the movement of carbon from the atmosphere into biomass
How does afforestation affect the carbon cycle?
Increases the movement of carbon from the atmosphere into biomass
How does marine pollution affect phytoplankton?
Pollution with toxic material can reduce phytoplankton populations
What does a reduction in phytoplankton mean for the carbon cycle?
Reduces the absorption of dissolved carbon dioxide
Can lead to higher levels of atmospheric CO2 as plankton absorb less into the oceans
How will climate change affect algae and the carbon cycle?
algae live in the under side of sea ice around Antarctica some of the carbon absorbed sinks to sea bed if climate change reduced sea ice area less CO2 may be removed form the sea
How is carbon released from DOM?
Released as CO2 by the aerobic respiration of soil organisms
What are some soil organisms that carry out decomposition?
Bacteria and fungi
What can increase oxygen supply to decomposers?
Ploughing
What does an increased oxygen supply to decomposers mean?
Decomposition takes place more rapidly
What does an increased rate of decomposition mean for the carbon cycle?
Amount of carbon in the soil DOM is reduced and the slung in the atmosphere is increased
What happens to methane gas in the atmosphere?
Gradually oxidised to CO2
What anaerobic environments are produced by humans?
Rice padi fields
Landfill sites
Anaerobic sediments in reservoirs
Livestock intestines
What are Anaerobic environments destroyed by drainage?
Waterlogged fields
Marshlands
Peat bogs
How will carbonic acid concentration in the sea be affected by human activities?
As atmospheric CO2 concentrations rise, dissolved CO2 increases, increases hydrogen ion concentration which makes the sea more acidic
How is methane and fossil fuels related?
When fossil fuels are being extracted methane may be released into the atmosphere
How does combustion affect the carbon cycle?
Combustion of fossil fuels and wood releases large amount of CO2 into the atmosphere
How can biomass be affected by human activities on a local scale?
Addition of compost/mulch to improve soil fertility
Deforestation and crop harvesting leading to reduced soil organic matter and soil erosion
Movement of biomass into the sea when sewage is discharged
Movement of marine biomass into the terrestrial system by fishing/aquaculture
How does the conservation of biomass carbon stores affect the carbon cycle?
Peat bogs and forests contain huge amounts of carbon protecting these from exploitation or damaging land use changes is important to stop CO2 rise in the atmosphere
How does the use of alternatives to fossil fuels affect the carbon cycle?
Renewable energy resources and nuclear power produce lower CO2 emissions than fossil fuels
How can afforestation affect the carbon cycle?
Large scale tree planting could remove lots of CO2
Once tree fully grown no more carbon absorbed but still a store so if harvested and used for construction then replanting to allow for additional carbon storage
What is Carbon Capture and Storage (CCS)?
Involves capturing carbon usually as CO2 so it is not released into the atmosphere
What is pre-combustion technology?
Changing the fuel used or the way it is combusted which is expensive but may make removing CO2 easier or more efficient
Why would post combustion not be practical for?
Small scale sources such as road vehicles
What is gasification?
Converts a fuel like coal into gaseous hydrogen and CO2
CO2 removed for storage
Hydrogen can be sued for vehicles, homes or industry
When burnt contains only water vapour
What is oxy-fuel combustion?
The use of pure oxygen so only CO2 and water Vapour are produced
Water vapour removed by cooling
So easier to remove CO2 as not mixed with other gases
What methods can be used to remove Carbon dioxide from the exhaust gases of fossil fuel combustion?
Dissolving it in a solvent
High pressure membrane filtration
Absorption/ desorption processes
Cryogenic separation
Graphene absorption
What is the problem with post- combustion tech?
No method is fully developed and large scale costs are unknown
How can CO2 be stored so it doesn’t return to the atmosphere?
Underground
Injected into oil reservoirs
Fractured basalt
What places can CO2 be stored underground?
Depleted aquifers
Oil fields
Gas fields
What is a benefit of injecting CO2 into oil reservoirs?
Provides the pressure required for secondary oil recovery
Why might CO2 be pumped into fractured basalt?
May react with the mineral in the rock producing solid carbonate minerals
