Carbon

Question 1

inorganic carbon

Answer 1

found in rocks as bicarbonates and carbonates

Question 2

organic carbon

Answer 2

found in plant material and living organisms

Question 3

gaseous carbon

Answer 3

found as CO2 and CH4 (methane)

Question 4

a carbon sink

Answer 4

any store which takes in more carbon than it emits, so an intact tropical rainforests is an example

Question 5

carbon source

Answer 5

any store that emits more carbon than it stores so a damaged tropical rainforest

Question 6

carbon sequestration

Answer 6

the transfer of carbon from the atmosphere to other stores and can be both natural and artificial. for example, a plant sequesters carbon when it photosynthesises and stores the carbon in its mass

Question 7

marine sediments and sedimentary rocks as a carbon store

Answer 7

the biggest store. 66,000-100,000 billion metric tons of carbon. the rock cycle and continental drift recycle the rock over time, but this may take thousands, if not millions of years

Question 8

oceans as a carbon store

Answer 8

the second biggest store, contains a tiny fraction of the largest store. 38,000 billion metric tons of carbon. the carbon is constantly being utilised by marine organisms, lost as an output to the lithosphere, or grains as an input from rivers and erosion

Question 9

fossil fuel deposits as carbon stores

Answer 9

fossil fuel deposits used to be rarely changing over short periods of time, but humans have developed technology to exploit them rapidly, though 4000 billion metric tons of carbon remain as fossil fuels

Question 10

soil organic matter as a carbon store

Answer 10

the soil can store carbon for over a hundred years, but deforestation, agriculture and land use change are affecting this store. 1500 billion metric tons of carbon stored

Question 11

atmosphere as a carbon store

Answer 11

human activity has caused Co2 levels in the atmosphere to increase by around 40% since the industrial revolution, causing unprecedented change to the global climate. 750 billion metric tons of carbon stored

Question 12

terrestrial plants as a carbon store

Answer 12

vulnerable to climate change and deforestation and as a result carbon storage in forests is declining annually in some areas of the world. 560 billion metric tons of carbon

Question 13

what is the biggest store of carbon

Answer 13

the lithosphere, with global stores unevenly distributed. for example, the oceans are larger in the southern hemisphere, and storage in the biosphere mostly occurs of land. terrestrial plant storage is focussed in the tropics and the northern hemisphere

Question 14

coal, oil, gas carbon emissions since 1750

Answer 14

coal = 673 gt
oil = 496 gt
gas = 202 gt

Question 15

atmosphere, ocean and land carbon taken in since 1750

Answer 15

atmosphere = 879 gt
ocean = 590 gt
land = 528 gt

Question 16

transfers in the carbon cycle

Answer 16

act to drive and cause changes in the carbon cycle over time. they all have impacts of varying magnitude over different length of time. biological and chemical processes determine how much carbon is stored and released.

Question 17

photosyntheis

Answer 17

living organisms convert carbon dioxide from the atmosphere and water from the soil, into oxygen and glucose using light energy.

Question 18

respiration

Answer 18

occurs when plants and animals convert oxygen and glucose into energy which then produces the waste products of water and CO2. it is therefore chemically the opposite of photosynthesis

Question 19

combustion

Answer 19

when fossil fuels and organic matter such as trees are burnt, they emit CO2 into the atmosphere, that was previously locked inside of them. this may occur when fossil fuels are burnt to produce energy, or if wildfires occur

Question 20

decomposition

Answer 20

when living organisms die, they are broken down by decomposers (bacteria/detritivores) which respire, turning Co2 into the atmosphere. some organic matter is also returned to the soil where it is stored adding carbon matter to the soil.

Question 21

diffusion

Answer 21

the ocean can absorb Co2 from the atmosphere, which has increased ocean acidity by 30% since pre-industrial times. the ocean is the biggest carbon store, but with carbon levels increasing seawater becomes more acidic which is harming aquatic life by causing coral bleaching. many of the worlds coral reefs are now under threat

Question 22

sedimentation

Answer 22

can happen on land or in the sea. for example, when shelled marine organisms die, their shell fragments fall to the ocean floor and become compacted over time to form limestone. organic matter from vegetation and decaying marine organisms is compacted over time, whether on land or in the sea, to form fossil fuel deposits

Question 23

weathering and erosion

Answer 23

inorganic carbon is released slowly through weathering. carbonation weathering occurs when Co2 in the air mixes with rainwater to create carbonic acid which aids erosion of rocks such as limestone. the carbon is moved through the water cycle and enters the oceans. marine organisms use the carbon the build their shells.

Question 24

metamorphosis

Answer 24

extreme heat and pressure forms metamorphic rock, during which some carbon is released and some becomes trapped

Question 25

volcanic outgassing

Answer 25

there are pockets of CO2 found in the earths crust. during a volcanic eruption or from a fissure in the earths crust, this CO2 can be released

Question 26

how is carbon stored in the sea

Answer 26

the majority of processes which take carbon out of the atmosphere and into the ocean occur in the top surface layer which makes up only a small proportion of the water in the worlds ocean. the carbon rich layer is then transferred down into the lower layers of the ocean and transported around the world due to thermohaline circulation

Question 27

how are phytoplankton linked to the carbon cycle

Answer 27

they are microscopic organisms that photosynthesise. they take in carbon and turn it into organic matter, as they are the base of the marine food web. when they get eaten, carbon is passed through the food chain. carbon is also released when they expire.

Question 28

how are shells linked to the carbon cycle

Answer 28

some organisms like plankton sequester CO2, turning the carbon into their hard outer shells and inner skeletons. when they die, some shells dissolve into the ocean water meaning the carbon becomes part of the deep ocean currents. and organisms that sink to the sea floor are compressed, turning into limestone - eventually fossil fuels

Question 29

co2 dissolving into the oceans

Answer 29

when Co2 naturally dissolves into the oceans it reacts with water to create carbonic acid. as the concentrations of Co2 in the atmosphere increases, oceans absorb more CO2 causing them to become more acidic. this acidification of the oceans could have long lasting negative effects

Question 30

how does oceanic circulation impact carbon storage

Answer 30

oceanic circulation provides a constant source of new water on the surface while transferring surface water to the deep ocean. this process enables the ocean to store more carbon. the colder the water the more CO2 stored.

Question 31

how is carbon storage different in parts of the ocean

Answer 31

• CO2 concentration is 10% higher in the deep ocean compared to the surface of the ocean
• polar regions hold more carbon than tropical regions
• warm tropical waters release CO2 to the atmosphere but cold high latitude oceans absorb in CO2 from the atmopshere

Question 32

thermohaline circulation

Answer 32

an ocean current that produces both vertical and horizontal circulation of cold and warm water around the worlds oceans.

Question 33

what is the rate of circulation in the ocean

Answer 33

it takes around 1000 years for any cubic metre of water to travel around the entire system.

Question 34

steps of oceanic circulation

Answer 34

1- the main current begins in polar oceans where the water is very cold, surrounding seawater sinks due to a higher density
2- the current is recharges as it passes antarctica by extra cold, salty, dense water
3- division of the main current; northward onto the indian ocean and into the western pacific
4- the two branches of warm water rise as they travel northward then loop back southward and westward
5- the now warmed surface waters continue circulating around the globe. on their eventual return to the north atlantic they cool and the cycle begins again

Question 35

how does temperature affect carbon absorption into the ocean

Answer 35

the colder the water, the more CO2 absorbed. therefore, ocean temperatures increase, the oceans will absorb less CO2. this would accelerate climate change and lead to further ocean warming

Question 36

terrestrial sequestration

Answer 36

• primary producers (plants) take carbon from the atmosphere to photosynthesise and release carbon when they respire
• vegetation growth depends of water, nutrients and sunlight
• when consumers eat plants, carbon from the plants is converted into fats and proteins
• micro-organisms feed on waste material from animals and plants
• animal and plant remains are faster to decompose than wood. decomposition is faster in tropical climates with high rainfall, temperatures and oxygen levels
• 95% of a trees biomass consists of CO2 which is sequestered and converted into cellulose.