Carbon Flashcards
ADD IMPACTS OF POOR OCEAN HEALTH AND FUTURE UNCERTAINTIES OF CLIMATE CHANGE
Which are the biggest and smallest carbon stores and how many PgC of carbon can they store?
Biggest: Lithosphere - 100,000,000 PgC
Smallest: Atmosphere - 750 PgC
How many times bigger is the hydrosphere store than the atmosphere?
50x bigger
What 2 elements make up the biogeochemical carbon cycle and which one is faster?
Geological and biological cycle, biological is faster
What are the 2 fast biological interactions?
- Atmosphere –> hydrosphere
- Atmosphere –> terrestrial biosphere
What is the flux when carbon moves from atmosphere to surface ocean, what rate does it occur at, and at what rate does the opposite flux occur?
Diffusion, 92 PgC/year, 90 PgC/year
What is the flux when carbon moves from atmosphere to surface ocean through phytoplankton and what % of global carbon sequestration does this account for?
Photosynthesis, 50%
What is the flux when vegetation sequesters carbon from the atmosphere, at what rate does this occur and how many times faster is it than respiration?
Photosynthesis, 123 PgC/year, 1000x faster
What is the flux when carbon moves from vegetation to soil store and at what rate does this occur?
Decomposition, 50 PgC/year
How is carbon in soil store released back into atmosphere?
Fungi/detritivores break it down and release CO2 via respiration
What is the fast biological to slow geological interaction?
Hydrosphere –> lithosphere
What is the process when carbon stored as dissolved CO2 or marine biota moves from surface ocean to deep ocean, at what rate does this occur at, and by what 3 fluxes does this occur through?
Downwelling, 90 PgC/year
1. Biological pump
2. Carbonate pump
3. Physical pump/thermohaline circulation
How much carbon is stored as surface sediment and what process occurs to transform it into CaCO3 or fossil fuels?
0.2 PgC/year, lithification
What process involves carbon moving from the lithosphere to hydrosphere then back to lithosphere again and at what rate does this occur?
Chemical weathering, 0.8 PgC/year
What is the slow geological to fast biological interaction?
Lithosphere –> atmosphere
Via what process can carbon move from lithosphere to atmosphere by anthropogenic activity and at what rate does occur?
Combustion, 35 PgC/year
What is the flux when carbon moves from lithosphere to atmosphere, at what rate does this occur, and how does it occur?
Volcanic outgassing, 0.15 PgC/year, continental crust undergoes subduction so carbon trapped within CaCO3 rocks released as CO2
Describe the process of limestone formation
- Formed from shale particles from marine organisms e.g. crabs
- Organisms die and shell fragments precipitate and sink to ocean floor
- Organic material buried under other organic materials and is lithified to limestone due to increase in pressure/compaction
Describe the process of shale formation
- Organic material precipitates onto ocean floor and covered in mud
- Material is embedded into mud layers and mud exposed to intense heat/pressure so is lithified to form shale
Describe the process of fossil fuel formation
- Organic material precipitates onto ocean floor and covered in mud
- Material decays anaerobically
- If organic material added at faster rate than it decays, becomes a fossil fuel
Describe the full process of chemical weathering to volcanic outgassing
- (Chemical weathering explanation)
- Breaks down rock into component ions e.g. Ca2+ which are transported to ocean in solution
- Ions react with bicarbonate to form CaCO3 which sinks to ocean floor and undergoes lithification to become sedimentary rock
- (Volcanic outgassing explanation)
What are the first 2 steps of an ocean pump PAD?
- Moves carbon from the surface ocean to the deep ocean
- This maintains the diffusion gradient, enabling more carbon to be sequestered from the atmosphere
Describe the process of the biological pump
- Phytoplankton use sunlight to convert CO2 into organic matter via photosynthesis
- Carbon enters food chain when phytoplankton eaten by small fish and some carbon released via respiration
- Marine biota die and precipitate to ocean floor - majority eaten by deep sea consumers or transported by ocean currents
- 0.1% carbon reaches the ocean floor to be stored as surface sediment and compacted into the lithosphere to become CaCO3
Describe the process of the carbonate pump
- Dissolved CO2 and bicarbonate ions generated from chemical weathering held in surface ocean
- Shellfish use carbon to make their shells comprised of CaCO3 and die so CaCO3 precipitates to ocean floor
- If reaches ocean floor, lithified/compacted to form limestone as part of slow geological cycle
Describe the process of the physical pump/thermohaline circulation
- At poles water is colder which leads to sea ice formation
- Increased density of water due to lower temp. and increased salinity
- Nutrient-rich, CO2-containing water sinks (downwelling)
- Colder water can hold more carbon so current picks up more carbon/nutrients
- Current gets closer to tropics so surface water gets warmer, less dense, and rises so upwelling of nutrient-rich waters
- Carbon released back into atmosphere which helps to maintain balance