Carbon Pathways and Processes

Question 1

Fast flows between Land and Atmosphere

Answer 1

Photosynthesis - CO2 ‘fixed’ into solid form as part of plant tissue
Respiration - CO2 released as by-product, over time more CO2 removed by photosynthesis than released by respiration
Decomposition - C02 released to atmosphere through feeding and oxidation mechanisms by bacteria
Combustion - industrial release of C02 in large amounts (85% global energy consumption from FF)

Question 2

Carbon cycle flows between Atmosphere to Ocean

Answer 2

Physical (inorganic) pump = diffusion from atmosphere to ocean, CO2 dissolves into ocean where dense cold water sink, determines acidity of ocean
Biological (organic) pump = phytoplankton absorb co2 through photosynthesis, carbon transferred along food chains as they consume one another
Carbonate pump = organic carbon to deep ocean when dead organisms sink

Question 3

Slow flows between Land and Ocean

Answer 3

= cycling of carbon between bedrock stores on land and ocean through weathering, erosion and deposition over millions of years

• large amounts removed in solution from limestone (e.g. llandudno cliff)
• carbonation takes place when rain collects in pools of exposed rock
• chalk regions are dissolved, calcium bicarb in solution transferred to river systems
• carbonate used to make shells which are deposited on ocean floor and lithified

Question 4

What is Carbon sequestration?

Answer 4

natural capture and storage of CO2 from atmosphere by physical and biological processes

Question 5

What is weathering?

Answer 5

on land, involving chemical weathering with rainwater. Carbonation occurs affecting rocks such as chalk and carboniferous limestone (link between water and carbon cycle)

Question 6

CARBON STORE EXAMPLE: Himilayas

Answer 6

• slow flow between land and ocean
• oceanic sediments rich in CaCO3 now actively weathered and transported back to oceans
• water cycle processes including monsoon rainfall and runoff play an important role