2.1.6: The global carbon cycle

Question 1

Stores

Answer 1

The amount of carbon held in the global system eg: the atmosphere, oceans and biosphere

Question 2

Flows

Answer 2

Are movements or transfers of carbon between stores eg: volcanic activity adds 0.1 gigatonnes of carbon to the atmosphere annually

Question 3

Inputs

Answer 3

Flows into stores

eg: CO2 added to the atmosphere by human activities

Question 4

Outputs

Answer 4

Flows leaving stores

eg: dissolved carbon carried from the land in solution by rivers

Question 5

1 gigatonne

Answer 5

1 billion tonnes

Question 6

GtC

Answer 6

1 gigatonne of carbon dioxide

Question 7

Carbon sequestration

Answer 7

Capture and storage of CO2

Question 8

Processes between the land and atmosphere
(fast carbon cycle)
4

Answer 8

photosynthesis
respiration
decomposition
fossil fuel combustion

Question 9

Carbon pathway from land to ocean
slow carbon cycle
process overview

Answer 9

Rainwater containing weak carbonic acid
reacts with limestone rock to produce
soluble calcium bicarbonate - moves thru water cycle
marine organisms use ^ to create shells
shells deposited as carbon-rich sediment
lithified

Question 10

Lithification

Answer 10

Process by which sediment is slowly turned into rock

Question 11

Weathering

Answer 11

In situ breakdown of rocks at or near the Earth’s surface by physical, chemical and biological processes.

Question 12

Difference between weathering and erosion?

Answer 12

Weathering happens where the material is and erosion is the removal of the material

Question 13

Carbonation

Answer 13

Rainwater combines with dissolved CO2 to forms weak carbonic acid and reacts with minerals in the rock form soluble bicarbonates.

Question 14

Carbonation

type of weathering

Answer 14

chemical weathering

Question 15

Chemical weathering transfers …. from rocks to the atmosphere and oceans every year

Answer 15

0.3 billion tonnes of carbon

Question 16

Examples of limestone landscapes in the UK

2

Answer 16

Limestone cliffs at Llandudno

Exposed rocks at Malham, Yorkshire

Question 17

Example of chalk landscapes in the UK

Answer 17

England’s South Downs

Question 18

Methods by which oceans take up CO2

2

Answer 18

biological pump and physical pump

Question 19

Physical pump

Answer 19

CO2 dissolved in oceans can be transferred to the deep oceans in areas where cold, dense surface water sink.
Process of downwelling

Question 20

Downwelling

Answer 20

Carries carbon molecules to great depths where they remain for centuries

Question 21

What determines ocean acidity

Answer 21

CO2 diffusion

Question 22

Biological pump

Answer 22

Organisms such as phyloplankton absorb CO2 via photosynthesis and then are consumed by other organisms in the marine food web.