3.1.1.3 The Carbon Cycle Flashcards
Describe the lithosphere
- Sedimentary rocks
- 99.9% of carbon
Describe the hydrosphere
- Constant diffusion
- Carbon is dissolved in
Describe the atmosphere
- Carbon dioxide accounts for less than 0.05% of the atmosphere
- Potent greenhouse gas
Describe the biosphere
- 60% is peat
- 0.0012% of carbon
Describe the cryosphere
- Permafrost
- less than 0 degrees for over 2 years
Name the factors driving change in magnitude over time
- photosynthesis
- respiration and decomposition
- combustion
- carbon sequestration
- weathering
Describe photosynthesis in relation to the carbon cycle
- Plants use energy from sunlight to combine carbon dioxide with water to form carbohydrates and oxygen
- Can be a long term store as trees live for ages
Describe respiration in relation to the carbon cycle
Plants release co2 back into the atmosphere
Describe decomposition in relation to the carbon cycle
Fungi and bacteria break down dead tissues off to form more simple inorganic substances
Carbon dioxide release is a byproduct of this process
Describe combustion in relation to the carbon cycle
- Fossil fuels contain carbon captured by living organisms
- Since the industrial revolution these fuels have been mine and combusted for energy
- This releases CO2
Describe the biological pump
Marine organisms such as phytoplankton use dissolved CO2 in photosynthesis, when these organisms die or get consumed, the carbon will sink to lower levels where it is sequestered
Describe calcification
- Marine organisms use carbon to create their shells
- When they die, this carbon sinks and is sequestered
Describe the ocean carbon pump
- Warm waters absorbs CO2
- Currents move this CO2 rich water to lower layers
- Sequestered
Describe weathering in relation to the carbon cycle
- Weathering breaks down rocks on the surface which is then carried to the ocean
- Large particles accumulate on the shore and eventually form shale rock
- Smaller dissolved particles can be used in shells of marine organisms
- They die and limestone can be formed from the carbonate in the shells
Name the two physical causes of change in the carbon cycle
- Wildfires
- Volcanoes
How do wildfires change the carbon cycle
- Carbon stores in plants enters the atmosphere
- Soil exposure increases carbon release from decomposition
- Vegetation is replaced by young plants which stores less carbon
- Accounts for 5-10% of annual CO2 emissions
How are wildfires changing over time
- Number have increased, especially in Western America
- Occurring 5x more often
- Lasting 5x longer
What was significant about the eruption of Mt Pinatubo in 1991
It cooled the earth’s temperatures by 0.6 degrees
Name the human factors causing change in the carbon cycle
- farming practices
- deforestation
- land use change
How does decomposition impact the carbon cycle
- waste products are burned by combustion
- exposed soil increases erosion into rivers and accelerates decomposition
How does change in land use impact the carbon cycle
- 2% of the world is covered by urban areas
- this area produces 97% of all emissions
- previous land was likely more valuable in storing carbon
Define the carbon budget
A list of all the carbon pools (stores), an estimate of their size and a summary of all the fluxes that includes inputs and outputs
Relationship between the water and carbon cycle and the atmosphere
- CO2 causes 20% of greenhouse effect
- water vapour accounts for 50%
How does carbon support life on earth
- 18% of the human body
- 50% of biomass in trees
- essential for photosynthesis
How does water support life on earth
- all life is supported by <1% of water
What is significant about Boundary Dam, Canada
- practice carbon capture and storage
- cut emissions by 90%
- costs $800mn
