1.3- Global Distribution And Size Of Major Carbon Stores

Question 1

Carbon takes different forms according to state:

Answer 1

• in solid form, carbon is combined with other elements and is stored within living things, in the minerals of rocks and soil and frozen in ice- graphite (pencil lead) and diamond are pure solid forms of carbon
• in liquid form, carbon is dissolved in water in the form of carbonic acid and dissolved organic carbon- liquid pure carbon is very unusual
• in gaseous form, carbon combines with oxygen to form carbon dioxide and other elements to form gases such as methane, a very powerful greenhouse gas

Question 2

Carbon cycle is the complex process carbon undergoes as it is transformed from

Answer 2

Organic carbon (form found in living organism such as plants and trees) to inorganic carbon and back again

Question 3

What are the main stores of carbon?

Answer 3

• lithosphere = biggest store of carbon
• hydrosphere
• biosphere
• cryosphere
• atmosphere

Question 4

Carbon in the lithosphere is distributed between these stores:

Answer 4

• marine sediments and sedimentary rocks may contain up to 100 million GtC
• fossil fuel deposits of coal, oil and gas
• soil organic matter
• peat

Question 5

Regarding the hydrosphere, attempts to collate measurements of the amount of carbon in the oceans have been made by

Answer 5

The Global Ocean Data Analysis Project using data from research ships; there is some variation in the results and figures can only be an approximation)

Question 6

The oceanic stores can be divided into three:

Answer 6

• the surface layer= where sunlight penetrates so that photosynthesis can occur
• the intermediate and the deep layer of water
• living organic matter too (fish, plankton, bacteria etc)
  = total for oceanic carbon up to 40,000 GtC

Question 7

Regarding the hydrosphere, when organisms die, their shells and other parts sink into deep water. Decay releases

Answer 7

• carbon dioxide into this deep water
• some material sinks right to the bottom where it forms layers of carbon-rich sediments
• over millions of years, chemical and physical processes may turn these sediments into rocks
• this part of the carbon cycle can lock up carbon for millions of years
• it is estimated that this sedimentary layer could store up to 100 million GtC

Question 8

The total amount of carbon stored in the terrestrial biosphere has been estimated to be

Answer 8

Approx 3000 GtC- the distribution of this carbon depends upon the ecosystem

Question 9

What are the main stores of carbon in the terrestrial biosphere?

Answer 9

• living vegetation
• plant litter
• soil humus
• peat
• animals

Question 10

Explain carbon content of living vegetation

Answer 10

• at the global level, 20% of carbon in Earth’s biosphere is stored in plants
• and the Amazon basin, which contains about 20%

Question 11

What is plant litter?

Answer 11

This is defined as fresh, undecomposed, and easily recognisable plant debris

• the type of litter is directly affected by the type of ecosystem
• in grasslands, there is very little above ground perennial tissue so the annual fall of litter is very low

Question 12

What is soil humus?

Answer 12

• originates from litter decomposition

- it gets dispersed throughout the soil by soil organisms such as earthworms

Question 13

What is peat?

Answer 13

The accumulation of partially decayed vegetation or organic matter unique to natural areas called peatlands

Question 14

Animals play a small role in the storage of carbon. They are however very important

Answer 14

In the generation of movement of carbon through the carbon cycle

Question 15

Carbon dioxide is less than 1% of the composition of the Earth’s

Answer 15

Atmosphere…but it’s really important

Question 16

when carbon dioxide reacts with water vapour it creates

Answer 16

Carbonic acid which means rain is slightly acidic, creating weathering (rain can also become more acidic as more carbon dioxide enters the atmosphere)

Question 17

Apart from carbon dioxide, ______ is another gas which is a compound of carbon and hydrogen- it is a product of biological decomposition and like carbon dioxide is a greenhouse gas

Answer 17

Methane

Question 18

Regarding the distribution of carbon where are 3 main examples?

Answer 18

• tropical and subtropical forests e.g. Brazil and Colombia, South America
• Boteal forest in Canada
• Antarctic tundra

Question 19

Regarding distribution of oil where are the 3 main sources?

Answer 19

1- Saudi Arabia
2- Canada
3- Venezuela

Question 20

Stores of carbon can either be

Answer 20

Sinks or source

Question 21

What is a carbon sink?

Answer 21

Absorbs more carbon than they release

Question 22

What is a carbon source?

Answer 22

Release more carbon than they absorb

Question 23

Regarding cryospheric storage,the majority of carbon is stored in

Answer 23

Permafrost of the tundra regions where some plant and life dies live, but on their death, it is frozen preventing decomposition and means the carbon is not released back into the atmosphere

Question 24

Mauna Loa Observstory have found that the global annual mean concentration of carbon dioxide in the atmosphere has increased markedly since

Answer 24

The industrial revolution = this increase is largely attributed to human derived i.e. anthropogenic sources, particularly the burning of fossil fuels and deforestation

Question 25

A graph of the change of the global annual mean concentration of carbon dioxide in the atmosphere has been named after the scientist who first started this research; it is called the

Answer 25

Keeling curve

Question 26

Keeling was one of the first scientists to gather evidence that linked

Answer 26

Fossil fuel emissions to rising levels of carbon dioxide

Question 27

Keeling’s research has been backed up by

Answer 27

Other readings from around the world; for example, the carbon dioxide trapped in ice caps from Antarctica and Greenland can be used to give a ‘proxy’ measure of carbon dioxide in the atmosphere at the time that snow was laid down