EQ1- Carbon

Question 1

Role of ocean in carbon cycle (1)

Answer 1

• contains about 38,000GT carbon one most significant stores
• bio pump
• carbonate pump
• physical pump
• size of ocean carbon store makes very important, as it has capacity to store excess carbon produced by human activities

Question 2

Biological pump (2)

Answer 2

• carbon stored dissolved CO2 in water or stored algae, plants+coral
• bio pump sequesters carbon from atmosphere thru plant growth of phytoplankton (photosynthesis)
• form basis ocean food web
• passed along food web carbon returned atmosphere by bio decay
• takes place timescale hrs-yrs + flux atmosphere+ocean= 11GT/yr

Question 3

Carbonate pump (3)

Answer 3

• only small proportion carbon enters carbonate pump
• when dead organic material e.g. dead shells+ phytoplankton sinks to ocean floor+ becomes sediment eventually = carbonate rocks e.g. limestone (geological carbon store) altho timescale millions yrs

Question 4

Physical pump (4)

Answer 4

-within oceans, physical pump, form ocean currents+ thermohaline circulation, moves carbon vertically + horizontally

Question 5

Role of ocean play an important role in regulating the composition of the atmosphere (1)

Answer 5

• phytoplankton in ocean sequester CO2 thru process photosynthesis pumping it out of atmosphere+ into ocean store
• action known bio pump+ process transfers 5-15GT carbon from atmosphere to ocean each yr

Question 6

Role of terrestrial photosynthesis in regulating composition of atmosphere (2)

Answer 6

-terrestrial photosynthesis enables plants sequester 100-120GT CO2/yr then released back into atmosphere thru respiration+ decomposition

Question 7

Both role of ocean and terrestrial photosynthesis in regulating the composition of the atmosphere (3)

Answer 7

-anything that affects lvl of phytoplankton in world’s oceans/ area land covered forest will have impact lvl carbon sequestration therefore affect composition atmosphere

Question 8

Role ocean+ terrestrial photosynthesis in regulating the composition of the atmosphere feedback systems (4)

Answer 8

• deforestation tropical rainforests -> droughts+ forest fires ->increases carbon lvls atmosphere ->+positive feedback systems further warming
• HOWEVER ->increase melting Arctic sea ice -> means more of ocean exposed direct sunlight (cos seasonal thaws last longer ) increasing photosynthesis by phytoplankton + decreasing atmospheric lvls carbon in possible negative feedback system regulating composition of atmosphere

Question 9

Importance soil health in maintaining balanced carbon cycle (1)

Answer 9

-stored carbon= healthy soil (nutrient+ water cycle)= high primary productivity

Question 10

Importance soils healthy maintaining balanced carbon cycle (2)

Answer 10

• carbon= vital in soils without nutrient+ water cycles can’t operate properly
• organic material medium by which carbon passed thru system+ also supports micro-organisms (e.g. worms) that maintain nutrient cycle, break down organic matter, provide pore spaces for infiltration+ percolation reducing soil erosion+ flood risk more storage water enhance plant growth (healthier soils)

Question 11

Importance soil health in maintaining balanced carbon cycle (3)

Answer 11

• healthy soils allow plant productivity
• plays major role global carbon cycle by absorbing some CO2 released when ppl burn coal, oil+ other fossil fuels
• carbon plants absorb becomes part of leaves, roots, stalks/ tree trunks+ ultimately soil