W&C: Carbon

Question 1

What systems can carbon be found in?

Answer 1

• Lithosphere
• Hydrosphere
• Atmosphere
• Biosphere
• Cryosphere

Question 2

What percentage of carbon on Earth is stored in the lithosphere?

Answer 2

Sedimentary rocks = 99.9%

Fossil fuels = 0.004%

Question 3

What is the second largest store of carbon?

Answer 3

Oceans

Question 4

What percentage of carbon on Earth is stored in the hydrosphere?

Answer 4

0. 04%
   * Majority is found deep in ocean in the form of dissolved inorganic carbon.*
   * Small amount is found at the ocean surface.*

Question 5

What percentage of carbon on Earth is stored in the atmosphere?

Answer 5

0.001%

Question 6

How is carbon stored in the atmosphere?

Answer 6

As carbon dioxide and in smaller amounts as methane.

Question 7

What percentage of carbon on Earth is stored in the biosphere?

Answer 7

0.004%

Question 8

Where is carbon stored in the biosphere?

Answer 8

In the tissues of living organisms - transferred to the soil when they die and decay.

Question 9

Where is carbon stored in the lithosphere?

Answer 9

In sedimentary rocks and fossil fuels.

Question 10

What percentage of carbon on Earth is stored in the cryosphere?

Answer 10

0.01%

Question 11

Where is carbon stored in the cryosphere?

Answer 11

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

Question 12

What type of system is the carbon cycle?

Answer 12

A closed system - there are inputs and outputs of energy, but the amount of carbon stays the same.

Question 13

Describe photosynthesis as a flow of carbon;

Answer 13

• Transfers carbon stored in atmosphere to biomass.
• Plants and phytoplankton use energy from sun and CO₂ —> glucose and oxygen for growth.

Carbon is then passed down the food chain and released through decomposition and respiration.

Question 14

Describe combustion as a flow of carbon:

Answer 14

• Transfers carbon stored in living, dead or decomposed biomass to the atmosphere by burning.
• Wildfires cause carbon flow.

Question 15

Describe ocean uptake and loss as a flow of carbon:

Answer 15

• CO₂ directly dissolved from atmosphere into the ocean.
• Also transferred to oceans when it is taken up by organisms that live in them.
• Carbon also transferred from ocean to atmosphere when carbon-rich water from deep in ocean rises to surface and releases CO₂.

Question 16

Describe sequestration as a flow of carbon:

Answer 16

• Carbon from atmosphere can be sequestered in sedimentary tocks or fossil fuels.

Question 17

What does it mean if something is sequestered?

Answer 17

It has been captured and held.

Question 18

Describe respiration as a flow of carbon:

Answer 18

• Transfers carbon from living organisms to the atmosphere.
• Plants and animals break down glucose for energy, releasing CO₂ and CH₄.

Question 19

Describe decomposition as a flow of carbon:

Answer 19

• Transfers carbon from dead biomass to atmosphere and the soil.
• Bacteria and fungi break organisms down - CO₂ and CH₄ are released.
• Some carbon is transferred to soil in the form of humus.

Question 20

Describe weathering as a flow of carbon:

Answer 20

• Transfers carbon from atmosphere to hydrosphere ad biosphere.

Question 21

Describe acid rain and its formation:

Answer 21

• Atmospheric carbon reacts with water vapour to form acid rain.
• On rocks, a chemical reaction occurs which dissolves rocks.
• Resulting molecules may be washed into sea.
• Here, they can react with dissolved CO₂ to form calcium carbonate - used by sea creatures to make shells.

Question 22

Give examples of fast carbon flows:

Answer 22

Photosynthesis

Respiration

Combustion

Decomposition

Question 23

Give an example of a slow carbon flow:

Answer 23

Sequestration

Question 24

What natural events can alter the magnitude of the carbon stores?

Answer 24

Wildfires and volcanic eruptions.

Question 25

How do wildfires alter the carbon cycle?

Answer 25

• Rapidly transfer large quantities of carbon from biomass to the atmosphere.
• Loss of vegetation = less photosynthesis = less carbon removed from atmosphere.
• Long term, can encourage growth of new plants = more photosynthesis.
• So, depending on amount and type of regrowth, fires can have a neutral effect on atmospheric carbon.

Question 26

How does volcanic activity alter the carbon cycle?

Answer 26

• Carbon stored in magma is released - majority enters the atmosphere as CO₂.
• Recent activity has released less CO₂ than human acitivities - but there is potential for a very large eruption to disrupt the cycle significantly.

Question 27

Since when has human impact on the carbon cycle greatly increased?

Answer 27

Since the industrial revolution.

Question 28

How does has the extraction and use of hydrocarbons altered the carbon cycle?

Answer 28

• Extracting and combusting fossil fuels releases CO₂ into atmosphere.
• This carbon would usually remain sequestered in lithosphere for thousands/millions of years.

Question 29

What are the main human activities that alter the carbon cycle?

Answer 29

Hydrocarbon extraction and use.

Deforestation.

Farming practices.

Land use change.

Question 30

How do farming practices alter the carbon cycle?

Answer 30

• Rearing animals - release CO₂ and CH₄ through respiration and digestion of food.
• Ploughing - releases CO₂ in soil.
• Growing rice - releases lots of CH₄.
• Population growth = increased food demand and production = carbon emissions increased.
• Machinery advances = increased carbon emissions.

Question 31

How does deforestation alter the carbon cycle?

Answer 31

• Clearing of forests for agriculture, logging or for space for new developments.
• Reduces size of carbon store and, if cleared forest is burned, there is rapid flow of carbon from biosphere to atmosphere.

Question 32

How do land use changes alter the carbon cycle?

Answer 32

• Removal of vegetation for buildings - reduces carbon storage in biosphere.
• Concrete production - releases CO_2.

Question 33

Carbon budget

Answer 33

The difference between the inputs of carbon into a subsystem and outputs of carbon from it.

Question 34

What determines whether something is a carbon source or a carbon sink?

Answer 34

The balance of inputs and outputs of a subsystem.

Question 35

Carbon source

Answer 35

The outputs of carbon outweigh the inputs, so it releases more carbon than it absorbs.

Question 36

Carbon sink

Answer 36

The inputs of carbon outweigh the outputs, so it absorbs more carbon than it releases.

Question 37

How can changes in the carbon stored in the atmosphere effect the climate?

Answer 37

• If concentration of greenhouse gases/gases containing carbon increases, temperatures are expected to rise - global warming.
• Changes in temperature can have knock-on effects with other aspects of climate, eg. more intense storms.