Carbon cycle & stores

Question 1

What is carbon?

Answer 1

chemically volatile, found in all life forms and sedimentary rocks

Question 2

What is the carbon cycle?

Answer 2

complex proces carbon goes through as it is transformed from organic carbon (in living organisms) to inorganic and back again

Question 3

Name the types of carbon

Answer 3

CO2, bio molecules (fats, oils, DNA-produced in living things), hydrocarbons, CH4/methane, CaCO3- calcium carbonate

Question 4

Primary origins of carbon

Answer 4

stored in mantle when earth formed- escapes at constructive and destructive plate boundaries
remains as CO2 in atmosphere, dissolved in oceans, held as biomass in organisms, bound in rocks

Question 5

How is carbon measured?

Answer 5

Gtc- gigatonne of CO2

Question 6

What is a flux?

Answer 6

measurement of the rate of flow of material between stores

Question 7

What is a carbon sink/store and source?

Answer 7

sink= absorbs more carbon than it releases
source= releases more carbon than it stores

Question 8

What is anthropogenic CO2?

Answer 8

CO2 generated by human activity

Question 9

Name the 4 main stores

Answer 9

Lithosphere, hydrosphere, biosphere, atmosphere

Question 10

Where is the lithosphere?

Answer 10

crust and upper mantle

Question 11

What is the pedosphere?

Answer 11

upper part of lithosphere- layer reacts with atmosphere, hydrosphere and biosphere

Question 12

How is carbon stored in the lithosphere?

Answer 12

inorganic= fossil fuels, carbon based sedimentary deposits( limestone)
organic= litter, organic matter and humic substances found in soil

Question 13

How is carbon distributed in the lithosphere?

Answer 13

marine sediments and sedimentary rocks- 100 million Gtc
soil organic matter- 1500-1600 Gtc
fossil fuels- 4100 Gtc
Peat- 250Gtc- dead, undecayed organic matter found in boggy areas

Question 14

Name the 3 hydrosphere stores

Answer 14

Euphotic zone- surface layer- photosynthesis occurs- 900Gtc
Twilight zone- intermediate- deep layer- 37100Gtc
Living organic matter(fish plankton bacteria) 30Gtc
&dissolved organic matter-700Gtc
=37000-40000 Gtc

Question 15

What happens organisms die?

Answer 15

dead cells, shells, etc. sink into deep water-decay releases co2
some material sinks to bottom- layers of carbon rich sediments- millions of years=rocks(locks carbon)

Question 16

What is the Biosphere?

Answer 16

total sum of all living matter- oceanic & terrestrial(3170Gtc)
Tropical rainforest=20%, temperate forest=7%, Boreal forest=26%

Question 17

Main stores of carbon in the terrestrial biosphere?

Answer 17

Living vegetation- 19% carbon in plants- direct in tissues, root system/below ground biomass- russia=25% worlds forest carbon, Amazon basin=20%
Plant litter- 70% leaf tissue in forest, woody litter increases with age
Soil humus- holds more carbon than vegetation- thick brown/black substance that remains after organism has decomposed
Peat- accumulation of partially decayed vegetation or organic matter unique to peatlands (5% of planet cover)
Animals- small role

Question 18

What do peatlands do?

Answer 18

Saturation obstructs oxygen flow to ground, anaerobic conditions that slow down rates of litter decomposition

Question 19

Explain the atmospheres carbon significance?

Answer 19

720-800Gtc- co2 higher than it has been for 800000

Small concentration- vital to regulate earths surface temperature as greenhouse gas- industrial co2 increased

Question 20

What does the Mauna Loa Observatory do?Why?

Answer 20

1958- measures atmospheric carbon

undisturbed air, remote location, minimal human activity

Question 21

How does the ocean store carbon?

Answer 21

absorbed directly from air, river water discharges carbon in solution

Question 22

How do plants store carbon?

Answer 22

convert sun’s energy to carbohydrates, store carbon for years, transfer to soil