The Carbon Cycle

Question 1

Carbon in the Lithosphere?

Answer 1

• 99.9% of carbon stored in sedimentary rock E.g. Limestone.

- 0.004% stored in fossil fuels.

Question 2

Carbon in the Atmosphere?

Answer 2

• CO2, smaller quantities as CH4

- 0.001% of carbon in the atmosphere

Question 3

Carbon in the Biosphere?

Answer 3

Carbon stored in living organisms. Transferred to soil when organisms die and decay.
- 0.004% of carbon in the biosphere/

Question 4

Carbon in the Cryosphere?

Answer 4

• Less than 0.001%

- Most in areas of permafrost.

Question 5

Carbon in the Hydrosphere?

Answer 5

• CO2 dissolved in rivers, lakes and oceans
• 0.04%, majority in the deep oceans
• Small amounts at ocean surface, where its exchanged with atmosphere

Question 6

What is the Carbon Cycle?

Answer 6

A process by which carbon is stored and transferred. It is a closed system, there are inputs and outputs of energy but the amount of carbon in the system remains the same.

Question 7

Carbon flows?

Answer 7

• Photosynthesis
• Combustion
• Respiration
• Decomposition
• Weathering
• Ocean uptake and loss
• Sequestration

Question 8

How do carbon stores change over time due to

1) Photosynthesis
2) Combustion
3) Ocean uptake and loss

Answer 8

1) Carbon from atmosphere to biomass. Plants use suns energy to convert CO2 into water, glucose and O2. Enable plant growth.
2) Carbon from living, dead or decomposed biomass to atmosphere by burning. E.g Wildfires
3) CO2 dissolved from atmosphere into oceans. Can also be taken up by organisms, phytoplankton etc.
Transferred from ocean to atmosphere when water is carbon rich, release CO2.

Question 9

How due carbon stores change over time due to

4) Respiration
5) Decomposition
6) Weathering
7) Sequestration

Answer 9

4) Carbon from living organisms to atmosphere.
5) Carbon from dead biomass to atmosphere and the soil in the form of humus.
6) Carbon from atmosphere to hydrosphere and biosphere. Atmospheric carbon reacts with water vapour to cause acid rain, could react with calcium carbonate in oceans preventing sea creatures making shells.
7) Carbon from atmosphere sequestered in sedimentary rock or as fossil fuels.

Question 10

Natural processes that can change the carbon cycle?

Answer 10

Wildfires

Volcanic Activity

Question 11

Effects of wildfires on carbon cycle?

Answer 11

Rapidly transfer large quantities of carbon from biomass to the atmosphere. Loss of vegetation decreases photosynthesis, less carbon removed from atmosphere.
Long-term:
encourage growth of new plants, which would take carbon from the atmosphere.

Question 12

Effects of Volcanic Activity on carbon cycle?

Answer 12

Carbon stored in the earths magma, released when there is an eruption.
Generally only a small impact nut have the potential to disrupt carbon cycle significantly if there was a large eruption.

Question 13

Human causes for impacts on the carbon cycle?

Answer 13

• Hydrocarbon extraction and use
• Farming practices
• Deforestation
• Land Use Changes

Question 14

How do Farming practice impact the carbon cycle?

Answer 14

• Animals release CO2 and methane
• Ploughing can release CO2 in the soil
• Rice paddies releases lots of methane

Question 15

How does Deforestation impact the carbon cycle?

Answer 15

• Forest cleared for agriculture, logging or developments
• Reduce size of carbon store
• If burnt, rapid flow from biosphere to atmosphere

Question 16

How do Land Use Changes impact the carbon cycle?

Answer 16

• If vegetation removed, reduce carbon store in biosphere

- Concrete production releases lots of CO2

Question 17

What is the Carbon Budget?

Answer 17

The difference between inputs of carbon into a subsystem and outputs of carbon from it.
The balance determines whether it acts as a carbon source of carbon sink.

Question 18

How does the Carbon Cycle affect the Atmosphere and Climate?

Answer 18

• Affects the amount of greenhouse gases
• Greenhouse gases conc. increases temperatures rise and cause global warming.
• Secondary effects of temp rise E.g Storms

Question 19

How does the carbon Cycle affect the Land?

Answer 19

• Allows plants to grow (photosynthesis) decompose (recycle nutrients).
• Changes could reduce carbon stored on land, E.g. temp rise, thawing of permafrost, release to the atmosphere.
• Increase in temps could also cause more wildfires.

Question 20

How does the Carbon Cycle affect the Oceans?

Answer 20

• CO2 dissolved into oceans from atmosphere
• CO2 used by phytoplankton etc. for photosynthesis and to form calcium carbonate shells
• increased CO2 levels, increase acidity, adverse effects on Marine life.
• Means less CO2 used by photosynthesis in oceans, less CO2 removed from atmosphere.