Carbon - stores and transfers

Question 1

What is carbon?

Answer 1

A chemical element needed by all plants and animals in order to survive.
It can can found in organic stores and can be found in each of earths systems.

Question 2

What are the different stores of carbon?

Answer 2

• Marine sediments and sedimentary rocks
• The ocean
• Fossil fuel deposits
• Soil organic matter
• Atmosphere
• Terrestrial plants

Question 3

What is the largest carbon store and how much does it hold?

Answer 3

Marine sediments and sedimentary rocks.
100,000 billion metric tons. 99.9% of earths carbon.
It is a long term store.

Question 4

What is a carbon sink?

Answer 4

A store that absorbs more than it releases. Also called a net carbon sink.

Question 5

What is a carbon source?

Answer 5

A store that releases more carbon than it absorbs. Also called a net carbon store.

Question 6

What is the second largest carbon store and how much carbon does it store?

Answer 6

The ocean.
38,000 billion metric tons.
Contains about 0.04% of the earths carbon. Most is found deep in the ocean in the form of dissolved inorganic carbon. A small amount of carbon on the surface is exchanged w/ the atmosphere.

Question 7

How much carbon do fossil fuel deposits store and why are they important carbon stores?

Answer 7

4000 billion metric tons. 0.004% of earths carbon.
Hydrocarbons like coal, oil and gas store carbon long term. Exploited for heat and power since the industrial revolution and the resulting combustion releases huge amounts of carbon into the atmos. = climate change.

Question 8

How much carbon is stored in soil organic matter and why is it an important carbon store?

Answer 8

1,500 billion metric tons.

Soils contain rotting organic matter and are important stores. Carbon can remains for 1000s of yrs.

Question 9

How is carbon stored in soil organic matter being released?

Answer 9

Deforestation, land use change and soil erosion.

Question 10

How much carbon is stored in the atmos. and why is it an important store?

Answer 10

750 billion metric tons.
Held in the form of carbon dioxide. Recently the amount has increased due to power stations and cars etc. - enhanced greenhouse effect.

Question 11

How much carbon do terrestrial plants store and why are they important carbon stores?

Answer 11

560 billion metric tons.
Plants vital for life on earth, they convert energy from the sun into carbohydrates. Plants store carbon for many yrs and transfer it to the soil.
Deforestation is rapidly releasing it into the atmos.

Question 12

What are the main transfers in the carbon cycle?

Answer 12

• Photosynthesis
• Respiration
• Decomposition
• Combustion
• Carbon sequestration
• Ocean carbon pump
• Weathering

Question 13

How does photosynthesis transfer carbon?

Answer 13

Transfers carbon stored in the atmos. to biomass. Terrestrial plants, photosynthetic algae and bacteria and phytoplankton absorb CO2 from the atmos. and use energy from the sun to turn CO2 and water into glucose. This process releases oxygen into atmos. and enables plant to grow. The glucose is used in respiration.

Question 14

How does respiration transfer carbon?

Answer 14

Transfers carbon from living organisms to the atmos. Coverts glucose into energy that can be used for growth and repair etc. and CO2 is released into atmos.

Question 15

How does decomposition transfer carbon?

Answer 15

When organisms die they are consumed by decomposers (e.g. bacteria, fungi and earthworms). During this process of decomposition, carbon from the bodies is returned to the atmos. as CO2. Some organic material passes into soil and may stored for 1000s of yrs.

Question 16

How does combustion transfer carbon?

Answer 16

Transfers carbon stored in living, dead or decomposed biomass into atmos.
When organic material is burned (e.g. at a power station) it is converted into energy, CO2 and water. Returns carbon that may have been stored in the lithosphere for millions of yrs to the atmos.

Question 17

How does carbon sequestration transfer carbon?

Answer 17

The transfer of carbon from the atmos. to plants, soil, rocks and fossil fuels and the ocean. It is both a natural and human process.
Carbon capture and storage used to describe the technological capturing of carbon released from power stations.

Question 18

How does the ocean transfer carbon?

Answer 18

Ocean atmos. exchange = When carbon on the ocean surface is exchanged w/ atmospheric carbon.
Also transferred when it is taken up by organisms that live in the ocean e.g. phytoplankton

Ocean carbon pump = when carbon moves from the ocean surface to deep in the ocean and then to the surface over time in a continuous loop

Question 19

How does weathering transfer carbon?

Answer 19

Involves the breakdown/decay of rocks. CO2 can be dissolved by rainwater to form acid rain. When it falls onto rocks it slowly dissolves them via a chemical reaction and the carbon is held in the solution. This carbon and other molecules from the reaction are then transported via the water cycle and can react to form calcium carbonate. This can be used by sea creatures to build shells.