Carbon Cycle m Flashcards
What systems can carbon be found in?
Lithosphere Hydrosphere Atmosphere Biosphere Cryosphere
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?
Oceans
What percentage of carbon on Earth is stored in the hydrosphere?
0.04%
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?
0.001%
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?
0.004%
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?
0.01%
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.
Draw a diagram of the carbon cycle:
https://s3.amazonaws.com/brainscape-prod/system/cm/323/929/758/a_image_card.jpg?1602671992
Describe photosynthesis as a flow of carbon;
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:
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:
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:
Photosynthesis
Respiration
Combustion
Decomposition
Give an example of a slow carbon flow:
Sequestration
What natural events can alter the magnitude of the carbon stores?
Wildfires and volcanic eruptions.
How do wildfires alter the carbon cycle?
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.
Deforestation.
Farming practices.
Land use change.
How do farming practices alter the carbon cycle?
Rearing animals - release CO2 and CH4 through respiration and digestion of food.
Ploughing - releases CO2 in soil.
Growing rice - releases lots of CH4.
Population growth = increased food demand and production = carbon emissions increased.
Machinery advances = increased carbon emissions.
How does deforestation alter the carbon cycle?
Clearing of forests for agriculture, logging or for space for new developments.
Reduces size of carbon store and, if cleared forest is burned, there is rapid flow of carbon from biosphere to atmosphere.
How do land use changes alter the carbon cycle?
Removal of vegetation for buildings - reduces carbon storage in biosphere.
Concrete production - releases CO2.
Carbon budget
The difference between the inputs of carbon into a subsystem and outputs of carbon from it.
What determines whether something is a carbon source or a carbon sink?
The balance of inputs and outputs of a subsystem.
Carbon source
The outputs of carbon outweigh the inputs, so it releases more carbon than it absorbs
Carbon sink
The inputs of carbon outweigh the outputs, so it absorbs more carbon than it releases.
How can changes in the carbon stored in the atmosphere effect the climate?
How can changes in the carbon stored in the atmosphere effect the climate?
If concentration of greenhouse gases/gases containing carbon increases, temperatures are expected to rise - global warming.
Changes in temperature can have knock-on effects with other aspects of climate, eg. more intense storms.
