The global carbon cycle

Question 1

Stores

Answer 1

Main carbon stores are the lithosphere (rocks and soil), hydrosphere (oceans), cryosphere (snow and ice), atmosphere and biosphere

Question 2

Lithosphere

Answer 2

• Largest carbon store
• Marine sediments and sedimentary rock
• 100,000 billions of metric tonnes
• Long-term store, rocks take millions of years to form
• Fossil fuel deposits- 4000 billions of metric tonnes, hydrocarbons which are now combusted

Question 3

Hydrosphere

Answer 3

• Ocean
• 38,000 billions of metric tons
• CO2 in atmosphere is dissolved into oceans
• Oceans have absorbed more CO2 due to increased greenhouse gases

Question 4

Atmosphere

Answer 4

• Carbon is held in the atmosphere in the form of CO2
• 750 billion of metric tons
• Amount of CO2 in atmosphere has increased dure to emissions from power stations, vehicles and deforestation
• Leads to enhances greenhouse effect and climate change

Question 5

Carbon sink

Answer 5

A store that absorbs more carbon than it releases e.g rainforests

Question 6

Carbon source

Answer 6

A store that releases more carbon than it stores

Question 7

Transfers

Answer 7

Processes involved in transferring carbon between stores
e.g photosynthesis
Inputs and outputs that affect the