What systems can carbon be found in?
What percentage of carbon on Earth is stored in the lithosphere?
Sedimentary rocks = 99.9%
Fossil fuels = 0.004%
What is the second largest store of carbon?
What percentage of carbon on Earth is stored in the hydrosphere?
Majority is found deep in ocean in the form of dissolved inorganic carbon.
Small amount is found at the ocean surface.
What percentage of carbon on Earth is stored in the atmosphere?
How is carbon stored in the atmosphere?
As carbon dioxide and in smaller amounts as methane.
What percentage of carbon on Earth is stored in the biosphere?
Where is carbon stored in the biosphere?
In the tissues of living organisms - transferred to the soil when they die and decay.
Where is carbon stored in the lithosphere?
In sedimentary rocks and fossil fuels.
What percentage of carbon on Earth is stored in the cryosphere?
Where is carbon stored in the cryosphere?
In the soil in areas of permafrost where decomposing plants and animals have frozen into the ground.
What type of system is the carbon cycle?
A closed system - there are inputs and outputs of energy, but the amount of carbon stays the same.
Describe photosynthesis as a flow of carbon;
- Transfers carbon stored in atmosphere to biomass.
- Plants and phytoplankton use energy from sun and CO2 ---> glucose and oxygen for growth.
Carbon is then passed down the food chain and released through decomposition and respiration.
Describe combustion as a flow of carbon:
- Transfers carbon stored in living, dead or decomposed biomass to the atmosphere by burning.
- Wildfires cause carbon flow.
Describe ocean uptake and loss as a flow of carbon:
- CO2 directly dissolved from atmosphere into the ocean.
- Also transferred to oceans when it is taken up by organisms that live in them.
- Carbon also transferred from ocean to atmosphere when carbon-rich water from deep in ocean rises to surface and releases CO2.
Describe sequestration as a flow of carbon:
- Carbon from atmosphere can be sequestered in sedimentary tocks or fossil fuels.
What does it mean if something is sequestered?
It has been captured and held.
Describe respiration as a flow of carbon:
- Transfers carbon from living organisms to the atmosphere.
- Plants and animals break down glucose for energy, releasing CO2 and CH4.
Describe decomposition as a flow of carbon:
- Transfers carbon from dead biomass to atmosphere and the soil.
- Bacteria and fungi break organisms down - CO2 and CH4 are released.
- Some carbon is transferred to soil in the form of humus.
Describe weathering as a flow of carbon:
- Transfers carbon from atmosphere to hydrosphere ad biosphere.
Describe acid rain and its formation:
- Atmospheric carbon reacts with water vapour to form acid rain.
- On rocks, a chemical reaction occurs which dissolves rocks.
- Resulting molecules may be washed into sea.
- Here, they can react with dissolved CO2 to form calcium carbonate - used by sea creatures to make shells.
Give examples of fast carbon flows:
Give an example of a slow carbon flow:
What natural events can alter the magnitude of the carbon stores?
Wildfires and volcanic eruptions.
How do wildfires alter the carbon cycle?
- Rapidly transfer large quantities of carbon from biomass to the atmosphere.
- Loss of vegetation = less photosynthesis = less carbon removed from atmosphere.
- Long term, can encourage growth of new plants = more photosynthesis.
- So, depending on amount and type of regrowth, fires can have a neutral effect on atmospheric carbon.
How does volcanic activity alter the carbon cycle?
- Carbon stored in magma is released - majority enters the atmosphere as CO2.
- Recent activity has released less CO2 than human acitivities - but there is potential for a very large eruption to disrupt the cycle significantly.
Since when has human impact on the carbon cycle greatly increased?
Since the industrial revolution.
How does has the extraction and use of hydrocarbons altered the carbon cycle?
- Extracting and combusting fossil fuels releases CO2 into atmosphere.
- This carbon would usually remain sequestered in lithosphere for thousands/millions of years.
What are the main human activities that alter the carbon cycle?
Hydrocarbon extraction and use.
Land use change.
How do farming practices alter the carbon cycle?