Carbon EQ1 (6.1)

Question 1

Carbon store definition:

Answer 1

Function as sources and sinks

Question 2

Carbon flux definition:

Answer 2

Also known as flows or processes. Movements of carbon from one store to another

Question 3

Carbon cycle definition:

Answer 3

The cycle by which carbon moves from one Earth store to another. It is a closed system made up of interlinked subsystems which are open and have inputs and outputs

Question 4

What are the three types of carbon stores on the Earth?

Answer 4

• Terrestrial (land)
• Atmosphere
• Oceanic

Question 5

What are the spheres carbon is found in?

Answer 5

• Atmosphere: CO2 and carbon compounds such as methane
• Hydrosphere: As dissolved CO2
• Lithosphere: As carbonates in limestone, chalk and fossil fuels. As pure carbon in graphite and diamonds
• Biosphere: As carbon atoms in living and dead organisms

Question 6

What is organic carbon released by?

Answer 6

Decomposition

Question 7

What are the carbon fluxes?

Answer 7

• Photosynthesis
• Respiration
• Decomposition
• Combustion

Question 8

what are the different ways that sedimentary carbonate rocks (limestone) are formed ?

Answer 8

• organic material such as coral and phytoplankton which absorb carbon decay at the bottom of the sea and over time they are compacted to form limestone
• precipitation can leave calcium carbonate deposits
• evaporation of sea water can leave behind calcium carbonate to form limestone

Question 9

what are the geological processes that release carbon ?

Answer 9

1. chemical weathering- decomposition of rock minerals due to natural acids in rainwater
2. outgassing- release of gas previously dissolved, trapped, frozen or absorbed in a material

Question 10

what is carbon sequestering ?

Answer 10

the process of CO2 being removed from the atmosphere and being held in solid or liquid form

Question 11

what are the processes in the bio-geochemical carbon cycle ?

Answer 11

• photosynthesis removes CO2 from atmosphere to promote plant growth
• respiration releases CO2 into the atmosphere when they breath
• decomposition of organic matter releases CO2 in to soils
• combustion of fossil fuels releases CO2 in to the atmosphere

Question 12

what are the 3 types of oceanic carbon pumps ?

Answer 12

1. biological pumps moves CO2 from the ocean surface to marine plants such as phytoplankton through photosynthesis. These may then be eaten by predators
2. Physical pumps move Carbon through thermohaline circulation and Upwelling can release deep water carbon back in to the atmosphere
3. carbonate pumps form sediment from dead organisms on the sea bed

Question 13

What is thermohaline circulation?

Answer 13

a global system of surface and deep ocean currents driven by the varying temperature differences. This includes downwelling where dense water sinks and upwelling where less dense water rises to the top

Question 14

what are the 2 different timescales that carbon fluxes in ecosystems vary ?

Answer 14

1. diurnally- during the day the fluxes are from atmosphere to ecosystem but during the night it is the opposite
2. seasonally- during winter there is high CO2 concentration due to lack of plant growth but in the spring this changes

Question 15

what are the sequestration patterns of trees ?

Answer 15

• 95% of trees biomass is CO2 converted in to cellulose
• carbon fixation turns CO2 into living organic compounds that grow
• amount of CO2 in plants dictated by balance of respiration and photosynthesis
• deforestation disturbs these carbon stores

Question 16

what are the sequestration patterns of Tundra soils and permafrost ?

Answer 16

• permafrost holds a lot of frozen carbon
• effects of global warming mean that permafrost is melting which releases carbon back in to the atmosphere- positive feedback loop

Question 17

what are the sequestration patterns of rainforests ?

Answer 17

• rain forests absorb more carbon than other terrestrial sources and account for 30% of global stores
• they are very sensitive environments and deforestation leads to released carbon

Question 18

why is organic material so important in soils ?

Answer 18

it is the medium that carbon travels through and without carbon the soil wouldn’t operate. Organic matter provide space for infiltration and water storage and also provides material for plant growth.

Question 19

What does the amount of carbon stores in soil depend on ?

Answer 19

• climate dictates the rates of plant growth and decomposition
• vegetation cover effects supply of organic matter
• soil type e.g clay has more carbon
• land use for example urbanisation can lead to carbon loss

Question 20

why is healthy soil so important ?

Answer 20

• it provides air, water and nutrients for micro organisms
• it sequesters more carbon than the plants themselves
• improves resistance to wetter weather due to infiltration

Question 21

how does the enhanced greenhouse effect effect the carbon cycle ?

Answer 21

it disturbs the carbon cycle and adds carbon to the atmosphere. Methane is 21 times more powerful than CO2 and Nitrous oxide is 250 times more powerful

Question 22

what is albedo ?

Answer 22

the rate a surface reflects light

Question 23

what are the impacts of fossil fuel consumption ?

Answer 23

• effects the equilibrium of sources and sinks
• changes in temperature lead to changes in precipitation and this changes river discharge
• melting permafrost releases CO2 in to the atmosphere
• more extreme weather patterns