✅3.1.1.3 - The Carbon Cycle

Question 1

What is a Carbon store?

Answer 1

The lithosphere, hydrosphere, cryosphere, atmosphere etc

Question 2

What is a carbon sink?

Answer 2

A store that takes in more carbon than it releases

Question 3

What is a carbon source?

Answer 3

A store that releases more carbon than it takes in

Question 4

What is a carbon transfer?

Answer 4

Processes that transfer carbon between stores

Question 5

What is a GtC?

Answer 5

A gigatonne of Carbon, 1 gigatonne = 1 billion tonnes

Question 6

What is anthropogenic CO2?

Answer 6

Carbon Dioxide generated by human activity

Question 7

What is a greenhouse gas?

Answer 7

Any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, therefore trapping and holding heat in the atmosphere

Question 8

What is the lithosphere?

Answer 8

The crust and uppermost mantle, the hard rigid outer layer of the earth

Question 9

What is weathering?

Answer 9

The breakdown of rocks in situ by weather, plants and animals

Question 10

What is the biosphere?

Answer 10

The total sum of all living matter

Question 11

What is Carbon Sequestration?

Answer 11

The capture of CO2 from the atmosphere, or capturing anthropogenic CO2 from large scale stationary sources such as power stations - put into long term storage

Question 12

Why is recycling carbon essential for life?

Answer 12

It enables food to be provided for plants and animals and creation of energy sources

Question 13

What can carbon form?

Answer 13

Biological molecules, Gases (eg CO2, CH4), Hydrocarbons

Question 14

What is the primary source of Carbon?

Answer 14

The Earth’s interior

Question 15

What are some of the stores in the carbon cycle?

Answer 15

Sedimentary rock, coal, oil, gas, plants, atmosphere, phytoplankton etc

Question 16

What are some of the transfers in the carbon cycle?

Answer 16

Weathering and erosion, rock cycle, photosynthesis, respiration, burning, decomposition, diffusion

Question 17

What is the largest store of carbon?

Answer 17

Marine sediments and sedimentary rock

Question 18

How is the ocean a store of carbon?

Answer 18

CO2 is absorbed directly from the air and river water discharges carbon in solutions

Question 19

How is soil organic matter a store of carbon?

Answer 19

They contain rotting organic matter and are important carbon stores. Carbon can remain in the soils for hundreds of years

Question 20

What are inorganic sources of carbon in the lithosphere?

Answer 20

Fossil fuels, eg coal, oil, natural gas and carbonate-based sedimentary deposits

Question 21

What are organic sources of carbon within the lithosphere?

Answer 21

Litter, organic matter and humic substances in soils

Question 22

What are the three stores of carbon in the lithosphere?

Answer 22

Marine sediments & sedimentary rocks
Soil organic matter
Fossil fuel deposits

Question 23

How is carbon in the biosphere divided up?

Answer 23

Into terrestrial and oceanic

Question 24

What are the main sources of carbon in the biosphere?

Answer 24

Living vegetation
Plant litter
Soil humus
Peat
Animals

Question 25

Where is most of the carbon in the cryosphere?

Answer 25

In the soil areas of permafrost where decomposing plants and animals have frozen into the ground

Question 26

What are methyl clathrates?

Answer 26

Molecules of methane frozen into ice crystals

Question 27

What does most frozen organic matter in permafrost consist of?

Answer 27

Partially decayed roots, whole roots and other plant material

Question 28

When is cryospheric carbon released into the atmosphere?

Answer 28

When the permafrost melts

Question 29

What are oceanic carbon stores divided into?

Answer 29

Surface later (euphotic zone) Intermediate and deep layer Living organic matter

Question 30

What is the euphotic zone?

Answer 30

The surface of the ocean where sunlight can penetrate and photosynthesis can take place

Question 31

Why are sediments and rocks in the ocean so carbon rich?

Answer 31

Because when organisms die, they sink to the bottom of the ocean and decay, releasing carbon

Question 32

What are fluxes?

Answer 32

Measurements of rate of flow of material between stores

Question 33

What are processes?

Answer 33

Physical mechanisms which drive movement and fuxes

Question 34

What type of system is the carbon cycle?

Answer 34

Closed

Question 35

What is burial and compaction?

Answer 35

Organic matter is buried by sediments and becomes compacted

Question 36

What is the geological component?

Answer 36

Where the carbon cycle interacts with the rock cycle in the processes of weathering, burial, subduction and volcanic eruptions

Question 37

What is a sere?

Answer 37

A succession which relates to a specific environment

Question 38

What is a lithosere?

Answer 38

Vegetation succession which occurs on bare rock

Question 39

When was the quaternary period?

Answer 39

2.6 million years ago to today

Question 40

Cold rainwater can hold...

Answer 40

...more CO2

Question 41

If rainwater hold more CO2, how is the rock affected?

Answer 41

It is weathered more

Question 42

What is eccentricity?

Answer 42

The change in the shape of the Earth's orbit around the sun

Question 43

How does the eccentricity of the Earth's orbit change?

Answer 43

In 100,000 year cycles. it changes from a thin ellipse to a circle and back again

Question 44

What is insolation?

Answer 44

The amount of solar radiation that reaches the Earth's surface

Question 45

What does lower insolation mean for global temperatures?

Answer 45

They decrease

Question 46

What natural factors can increase input of atmospheric CO2?

Answer 46

Periods of increased volcanicity

Question 47

What human factors can increase input of atmospheric CO2?

Answer 47

Burning fossil fuels Causing more wildfires Climate change causing melting of tundra

Question 48

What natural factors can reduce removal of CO2 from the atmosphere

Answer 48

``` Glacial periods (less vegetation) Interglacial periods (warmer oceans, less CO2 absorebd) Winter in the northern hemisphere, hibernation ```

Question 49

What human factors can reduce the removal of CO2 from the atmosphere

Answer 49

Clearing vegetation from from areas | Climate change resulting in warmer oceans

Question 50

What percentage of anthropogenic CO2 is from fossil fuel burning?

Answer 50

90%

Question 51

How does ploughing increase CO2 emissions?

Answer 51

It aerates soil, increasing microbial activity and therefore decomposition, more CO2 released

Question 52

What are the human factors which can cause changes in the carbon cycle?

Answer 52

``` Combustion of fossil fuels Land use Farming practices Carbon sequestration in soils Deforestation Urbanisation ```

Question 53

How does deforestation affect the carbon cycle?

Answer 53

Above ground biomass is burned, releasing CO2 Forest clearing may accelerate decay of dead wood, litter or below ground organic carbon In a natural system, trees would decay very slowly Upsets the balance of carbon in the forest

Question 54

How can deforestation impact soils?

Answer 54

Without shade from trees, they dry out

Question 55

How does urbanisation affect the water cycle?

Answer 55

Replacing open countryside with concrete and tarmac replaces important stores Urban areas produce far more CO2 than rural ones

Question 56

What does terrestrial/biological sequestration involve?

Answer 56

The use of plants to capture CO2 from the atmosphere and store it in stems and roots

Question 57

What is the carbon budget?

Answer 57

Uses data to describe the amount of carbon that is stored and transferred within the carbon cycle

Question 58

What is the enhanced greenhouse effect?

Answer 58

The impact on the climate from the additional heat retained due to increased CO2

Question 59

What is geo-sequestration?

Answer 59

Technology capturing greenhouse gas emissions from power stations and pumping them into underground reservoirs

Question 60

What is radiative forcing?

Answer 60

The difference between the incoming solar energy absorbed by the earth and energy radiated back to space

Question 61

What is soil organic carbon (SOC)?

Answer 61

The organic constituents of the soil, tissues from dead plants/animals, products of decomposition, microbial biomass etc.

Question 62

How is the carbon budget affecting ocean salinity?

Answer 62

Decrease in salinity in the deep North Atlantic, more freshwater being added to the ocean. Slowing down of large scale oceanic circulation