Carbon Cycle

Question 1

What are the earth systems?

Answer 1

Lithosphere
Atmosphere
Hydrosphere
Biosphere
Cryosphere

Question 2

How is carbon found in the Lithosphere?

Answer 2

• Over 99.9% of the carbon on Earth is stored in sedimentary rocks such as limestone.
• About 0.004% of the carbon on Earth is stored in fossil fuels.

Question 3

How is carbon found in the Atmosphere?

Answer 3

• Carbon is stored as carbon dioxide and in smaller quantities as methane in the atmosphere.
• The atmosphere contains about 0.001% of the Earths carbon

Question 4

How is carbon found in the Hydrosphere?

Answer 4

• Dissolved in river, lakes and oceans.
• Ocean second largest stores- 0.04%
  Found deep in the ocean in the form of dissolved inorganic carbon.
• small amounts on surface are exchanged with the atmosphere.

Question 5

How is carbon found in the Biosphere?

Answer 5

• Stored in the tissues of living organisms. It is transferred to the soil when living organisms die and decay.
• Contains 0.004%

Question 6

How is carbon found in the Cryosphere?

Answer 6

• Less than 0.01%

- Permafrost where decomposing plants and animals have frozen into the ground

Question 7

What are the stores?

7

Answer 7

Atmosphere
Vegetation
Soils 
Fossil fuels 
Oceans 
Sediments 
Earth's crust

Question 8

What are the carbon flows?

7

Answer 8

Photosynthesis
Combustion
Ocean uptake and loss
Sequestration 
Respiration
Decomposition
Weathering

Question 9

What are the natural processes that change the carbon cycle?

Answer 9

Wildfires

Volcanic Activity

Question 10

How do wildfires affect carbon stores?

Answer 10

Wildfires rapidly transfer large quantities of carbon from biomass (or soil) to the atmosphere. Loss of vegetation decreases photosynthesis, so less carbon is removed from the atmosphere.

Question 11

How do wildfires affect carbon stores in the long term?

Answer 11

In the longer term, however, fires can encourage the growth of new plants, which take in carbon from the atmosphere for photosynthesis. Depending on the amount and type of regrowth, fires can have a neutral effect on the amount of atmospheric carbon.

Question 12

How does volcanic activity affect carbon stores?

Answer 12

Carbon stored within the Earth in magma is released during volcanic eruptions. The majority enters the atmosphere as CO2
Recent volcanic eruptions have released much less CO2 than human activities. However, there is the potential for a very large eruption to disrupt the carbon cycle significantly.

Question 13

What event dramatically changed the carbon cycle?

Answer 13

The industrial revolution

Question 14

What are human currently causing?

Answer 14

Carbon flows from the lithosphere and biosphere to the atmosphere to happen much faster than they would naturally.

Question 15

What are the human causes of change?

4

Answer 15

Hydrocarbon (fossil fuel) extraction and use
Deforestation
Farming practices
Land use change

Question 16

How does Hydrocarbon (fossil fuel) extraction and use effect stores?

Answer 16

Extracting and burning (combustion) of fossil fuels releases CO, into the atmosphere.
Without human intervention, the carbon would remain sequestered in the lithosphere for thousands or millions of years to come.

Question 17

How does deforestation affect stores?

Answer 17

Forests may be cleared for agriculture, logging, or to make way for developments.
Clearance reduces the size of the carbon store and, if the cleared forest is burned, there is a rapid flow of carbon from the biosphere to the atmosphere.

Question 18

How does farming practices affect stores?

Answer 18

Agricultural activities release carbon into the atmosphere:
-Animals release CO, and methane when they breathe and digest food.
-Plowing can release CO, stored in soil.
-Growing rice in rice paddies releases a lot of methane.
As the world’s population has risen, so has food production. AS a result, carbon emissions from farming practices have increased. Mechanization of farming has also increased CO, emissions.

Question 19

How does Land use change affect stores?

Answer 19

As well as deforestation (see above), the change of land use from natural or agricultural to urban is a major source of carbon:

• Vegetation is removed to make way for buildings-this reduces carbon storage in the biosphere.
• Concrete production releases lots of CO, and lots of concrete is used when urban areas expand.

Question 20

What is the carbon budget?

Answer 20

Is the difference between the inputs of carbon into a subsystem and outputs of carbon from it.

Question 21

What are the inputs in the atmosphere?

Answer 21

volcanic eruptions, burning fossil fuels, respiration and ocean loss.

Question 22

What are the outputs of the atmosphere?

Answer 22

photosynthesis, sequestration, decomposition, chemical weathering and ocean uptake.

Question 23

What does the balance of the inputs and outputs of a subsystem determines?

Answer 23

determines whether it acts as a carbon source (the outputs of carbon outweigh the inputs, so it releases more carbon than it absorbs) or a carbon sink (the inputs of carbon outweigh the outputs , so it absorbs more carbon than it releases).

Question 24

What does the carbon cycle effect?

Answer 24

The carbon cycle affects the amount of gases containing carbon (e.g. CO, and methane) in the atmosphere. These are greenhouse gases- they trap some of the Sun’s energy, keeping some of the heat in and keeping the planet warm.

Question 25

what is gonna happen at greenhouse gas concentrations rise?

Answer 25

As the concentrations of greenhouse gases in the atmosphere increase (e.g. due to changes in the carbon cycle caused by human activities such as deforestation and the burning of fossil fuels) temperatures are expected to rise. This is global warming.

Question 26

What will changes in temp affect?

Answer 26

Changes in temperature across the globe will affect other aspects of the climate, e.g. more intense storms are predicted.

Question 27

What does the carbon cycle allow?

Answer 27

The carbon cycle allows plants to grow-if there was no carbon in the atmosphere, plants could not photosynthesise. If there was no decomposition, dead plants would remain where they fell and their nutrients would never be recycled.

Question 28

What can changes in the carbon cycle reduce?

Answer 28

Changes in the carbon cycle can reduce the amount of carbon stored in the land, eg. warmer temperatures caused by global warming are causing permafrost to melt. This releases carbon previously stored in the permafrost into the atmosphere.

Question 29

What could an increase in temp cause?

Answer 29

An increase in global temperatures could also increase the frequency of wildfires

Question 30

How does carbon enter the oceans?

Answer 30

As part of the carbon cycle, carbon dioxide is dissolved directly into the oceans from the atmosphere.

Question 31

How is CO2 used by in the oceans?

Answer 31

CO2 in oceans is used by organisms such as phytoplankton and seaweed during photosynthesis and by other marine organisms to form calcium carbonate shells and skeletons. Increased levels of CO2 in the atmosphere can increase the acidity of the oceans because the oceans initially absorb more CO2 This can have adverse effects on marine life.

Question 32

How does global warming affect the oceans?

Answer 32

Global warming can also affect oceans. For example, organisms that are sensitive to temperature, e.g. phytoplankton, may not be able to survive at higher temperatures, so their numbers decrease. This means that less CO, is used by them for photosynthesis, so less carbon is removed from the atmosphere.

Question 33

What would warning oceans lead to?

Answer 33

Warmer water is also less able to absorb CO, so as temperatures rise the amount of CO, that could potentially be dissolved in the sea decreases.