Carbon cycle

Question 1

What is Carbon?

Answer 1

A basic element
Needed by all plants and animals to survive
Exceptionally diverse
Can come in form of gas, solid, diamonds, limestone, graphite, wood and plastics

Question 2

Why is carbon important?

Answer 2

Carbon compounds are the basis for all life

Changing amounts of carbon in the atmosphere, the oceans and in rocks alter the climate and how species develop

Question 3

What is the largest store of carbon?

Answer 3

Marine sediments and sedimentary rocks - this is a long term store, taking millions of years to form.

Question 4

How much carbon does marine sediments and sedimentary rock hold?

Answer 4

100,000 billion metric tons.

Question 5

How much carbon does the ocean hold?

Answer 5

38,000 billion metric tons.

Question 6

How much carbon does fossil fuel deposits hold?

Answer 6

4000 billion metric tons.

Question 7

How much carbon does soil organic matter hold?

Answer 7

1500 billion metric tons.

Question 8

How much carbon is in the atmosphere?

Answer 8

750 billion metric tons.

Question 9

How much carbon is in terrestrial plants?

Answer 9

560 billion metric tons.

Question 10

What is the global pattern of carbon storage in plants?

Answer 10

Carbon stored in plants is the greater in the middle and high latitudes of the Northern hemisphere and tropic of cancer. Therefore, due to the dry climate, there is less vegetation and additionally less plants for the carbon to be stored on.

Question 11

What is a carbon sink?

Answer 11

A store that absorbs more carbon than it releases - sea, vegetation

Question 12

What is a carbon store?

Answer 12

A store that releases more carbon than it absorbs - humans

Question 13

What are fluxes?

Answer 13

Changes in the amount of carbon held in each store.

Question 14

What are the important carbon compounds?

Answer 14

Methane
Calcium Carbonate
Hydrocarbons
Bio-molecules

Question 15

Where does carbon originate from?

Answer 15

The earths interior - mantle

Question 16

How does carbon escape the mantle?

Answer 16

At constructive and destructive plate boundaries as well as hotspot volcanoes

Question 17

Define anthropogenic

Answer 17

Generated by human activity

Question 18

What is the Biosphere?

Answer 18

The total sum of all living matter

Question 19

What is carbon sequestration?

Answer 19

The capture of carbon dioxide from the atmosphere or capturing anthropogenic CO2 from large-scale stationary sources like power plants before it is released into the atmosphere. Once captured, it is put into long-term storage

Question 20

What is a greenhouse gas?

Answer 20

Gaseous compound
Capable of absorbing infrared radiation
Traps and holds heat in the atmosphere

Question 21

How does photosynthesis work?

Answer 21

Green plants make their food from carbon-dioxide and water in the presence of sunlight.
Oxygen gas is released.

Question 22

How does respiration work?

Answer 22

Oxygen is combined with carbohydrates to release the stored energy from the carbs.
Water and carbon dioxide are by-products

Question 23

What is decomposition?

Answer 23

Carbon from the bodies of dead organisms is returned to the atmosphere as carbon dioxide

Question 24

What is combustion?

Answer 24

Organic material containing carbon is burned in the presence of oxygen, it is converted into energy, carbon dioxide and water

Question 25

What is burial and compaction?

Answer 25

Organic matter is buried by sediments and becomes compacted

Question 26

What is weathering?

Answer 26

The breakdown or decay of rocks in their original place at or close to the surface. When carbon dioxide is absorbed by rainwater it forms a middle acidic carbonic acid

Question 27

How does a wildfire lead to changes in the carbon cycle over time?

Answer 27

Plant carbon enters atmosphere
Important stores are eliminated
Soil is exposed, releases carbon from decaying plant matter
Vegetation is replaced by young plants that store less carbon - net decrease in the carbon store
All factors increase CO2 in atmosphere - greenhouse heating

Question 28

How do farming practices lead to changes in the carbon cycle over time?

Answer 28

Ploughing introduces air to soil, decomposition accelerates and carbon is released
Emissions from tractors increase CO2 in air
Livestock release methane as a by-product of digestion ]Rice paddies generate methane

Question 29

How does urbanisation lead to changes in the carbon cycle?

Answer 29

Urban growth reduces the amount of surface vegetation
CO2 emissions from energy consumption, transport, industry and domestic use increase
Increase in CO2 emissions rom cement manufacturing required for buildings

Question 30

What is the enhanced greenhouse effect?

Answer 30

A natural process of heat balance essential for life on earth

Question 31

How much of the atmosphere is nitrogen?

Answer 31

78%

Question 32

How much of the atmosphere is oxygen?

Answer 32

21%

Question 33

How much of the atmosphere is other?

Answer 33

1%

Question 34

In what layer of the atmosphere does the enhanced greenhouse effect occur?

Answer 34

Troposphere

Question 35

How many kilometres away is the sun?

Answer 35

150 million km

Question 36

How does the enhanced greenhouse effect work?

Answer 36

Sun emits shortwave UV radiation - passes through earths atmosphere
Some absorbed by land or sea, some is reflected back as long wave infrared radiation
Mixture of gases absorb radiation - emit back to earth - effectively trapping it.

Question 37

How much of the shortwave UV radiation that the sun emits is absorbed by land or sea?

Answer 37

51%