Carbon Cycle Flashcards
What is the biogeochemical carbon cycle?
A closed system in which carbon is moved and stored in the lithosphere, biosphere, atmosphere and hydrosphere
What is the difference between a store and a flux?
A store holds carbon for a long period of time and flux is a transportation of carbon that creates a cycle and feedback
Why is the carbon cycle important?
Economic development relies on fossil fuels
Energy security and scarcity is the cause of conflict
Combustion of carbon affects the climate
The desire for carbon is destroying ecosystems
What is different about the willow tree as a store of carbon?
Sequestration and carbon release are equal in concentration so no more carbon dioxide is released that was absorbed
Name the four carbon stores
Lithosphere
Biosphere
Atmosphere
Hydrosphere
Describe the lithosphere including the form of carbon stored
The crust and upper mantle - fossil fuel and sedimentary rock deposits
Describe the biosphere and the store of carbon
Regions of the surface and atmosphere occupied by living organisms - organic molecules in living and dead organisms
Describe the atmosphere and type of carbon stored
An envelope of gases surrounding the earth - carbon dioxide
Describe the hydrosphere and carbon stored
All the water stores on the earth surface - dissolved carbon dioxide in the ocean
Name three rocks carbon is stored in
Limestone, shale and coal
How significant is the ocean as a store of carbon
It is the largest store of carbon on earth holding approx 80% of the world’s carbon
How are the Himalayas significant to storing carbon?
A large store of carbon as it started as oceanic sediment so has a lot of calcium carbonate which is actively weathered carbon and transported to the ocean
Fill in the gaps
80% of carbon containing rock is from shell building aka (1) organisms and plankton which is (2) to form rock such as limestone
1 - calcifying
2 - lithified
Fill in the gaps
20% of rocks contain (1) carbon formed from (2) in embedded layers of rock which is how (3) is formed
1 - organic
2 - heat and pressure
3 - shale
How do carbon fossil fuels form?
- Takes 300m years
- From organic material
- Decays anaerobically in rivers and oceans
- The deeper the deposit, the more heat and pressure on deposits
- When material builds up quicker than it can decay layers of organic carbon form oil, coal and natural gas
How are oil and gas formed?
- Remains of tiny aquatic animals and plants
- Gas and oil in pockets of rock migrate through the crust until it meets caprocks
- Natural has are fractions of oil molecules found in crude oil
- Hydrocarbon deposits include oil shales, tar sands and gas hydrates
How is coal formed?
Remains of trees, plants and ferns sinking to the bottom of a swamp or damp surrounding
Over time the heat and pressure on deposits produced chemical and physical changes in plant layers which formed peat
Name the four types of coal
Anthracite
Bituminous
Soft
Peat
Describe anthracite
Highest energy content and greatest store of carbon
Describe bituminous
Forms as high pressure on lignite and is a poorer quality of anthracite
Describe soft coal
E.g. brown coal
25-35% carbon
Lower energy potential and a major global source of energy
Describe peat coal
An important carbon store of decaying trees, ferns and plants that has not yet turned to coal
Volcanic activity Increase in CO2 Loss of (1) from rocks Increased temperature (2) of air Increased rainfall from condensation Increase in (3) More (4) are deposited on the ocean floor More carbon to be stored in (5) Cycle repeats
1 - carbon 2 - uplift 3 - chemical weathering 4 - ions 5 - rocks
Describe the oceanic carbon cycle
CO2 enters the ocean by diffusion on the surface
The volume of CO2 depends on wind, concentration of CO2 and water temperature
Once the CO2 is dissolved in the sea, how does it enter the carbon cycle?
Physical carbon pump
Biological carbon pump
Carbonate pump
What is the physical carbon pump
Oceanic circulation distributes CO2 including thermigaline circulation so the colder the water the greater the potential for CO2 sequestration
What is thermohaline circulation
The movement of seawater in a pattern of flow dependency on variations of temperature which causes change in salt content and density
What is the biological carbon pump?
Phytoplankton photosynthesise sun light at the ocean surface taking up CO2 which then enters the food chain and eventually calcifies to make shells and rock