Carbon - key terms

Question 1

Flux

Answer 1

Transfers in the carbon cycle that act to drive and cause changes over varying lengths of time.

Biological and chemical processes determine how much carbon is stored and released

Question 2

Photosynthesis

Answer 2

Process where plants convert carbon dioxide from the atmosphere and water from the soil, into oxygen, glucose using light energy.

They sequester carbon as they remove Co2 from the air.

Question 3

Combustion

Answer 3

When fossil fuels and organic matter such as trees are burnt, they emit CO ₂
into the atmosphere , that was previously locked inside of them

Question 4

Decomposition

Answer 4

When living organisms die they are broken down by decomposers like bacteria, adding carbon matter into the soil and co2 back into the atmosphere.

Question 5

Sedimentation

Answer 5

Dead shelled marine organisms become compacted over time, forming limestone and fossil fuel deposits

Question 6

Weathering and Erosion

Answer 6

Carbon is released slowly through weathering. Co2 in the air mixes with rainwater, creating carbonic acid which erodes rocks like limestone.

This carbon gets transported via the water cycle into the oceans, where organisms use it to build their shells..

Question 7

Metamorphosis

Answer 7

Carbon is returned to the atmosphere via metamorphism (extreme heat and pressure) of limestone at depth in subduction zones

Question 8

Volcanic outgassing

Answer 8

Pockets of CO2 are found in the Earth’s crust. During a
volcanic eruption or earthquake, this Co2 can be released.

Question 9

Marine Sediments and Sedimentary Rock stores - lithospheric store

Answer 9

Largest store

Accumulation of sedimentary rocks in the earths crust - contains 100,000 million billion metric tons of
carbon. The rock cycle recycles the rock over time, but this takes millions of years

Question 10

Oceanic store (hydrosphere store)

Answer 10

Second largest store.

Carbon is constantly being
utilized by marine organisms, lost as an output to the lithosphere, or gains as
an input from rivers and erosion.

Question 11

Fossil Fuel Deposits - Lithospheric store

Answer 11

Fossil fuel deposits used to be rarely changing over short periods of time, but
humans have developed technology to exploit them rapidly, thus are a ‘dynamic’ store

Question 12

Organic soil matter -
Lithospheric store

Answer 12

The soil can store carbon for over a hundred years, but deforestation,
agriculture and land use change are affecting this store.

Question 13

Atmospheric store

Answer 13

Human activity has caused CO ₂ levels in the atmosphere to increase by
around 40% since the industrial revolution , causing unprecedented change
to the global climate

Question 14

Terrestrial plants - biosphere

Answer 14

Vulnerable to climate change and deforestation.

Carbon
storage in forests is declining annually.

Question 15

Carbon sink

Answer 15

A store which takes in more carbon than it emits, like an intact
tropical rainforest

Question 16

Carbon source

Answer 16

A store which emits more carbon that it stores.

Damaged rainforests release carbon via decomposition, soil degradation exacerbates this.

Question 17

Carbon Sequestration

Answer 17

Long term capturing and storage of carbon in a sink.

A plant sequesters carbon when it
photosynthesises and stores the carbon in its biomass.

Question 18

Variations in fluxes

Answer 18

Plants can absorb Co2 in a matter of seconds

Dead organic material may be held deep in the earth for hundreds of years so it doesn’t decay

Question 19

Ocean surface layer

Answer 19

Carbon rich water
in the surface layer is
transferred down into the
lower layers of the ocean and transported around the world.

Home to Phytoplankton, where they convert light energy into matter for zooplankton

Question 20

Thermohaline circulation

Answer 20

The upwelling and downwelling of water currents, driven by differences in salinity and temperature.

Cold polar water sinks due to high density, the current is recharges as it passes Antarctica with more cold water.

Main current divides into the Indian Ocean and Wester Pacific

These branches warm and rise as they travel North and Westward

Warmed surface waters continue circulating around the globe.

On their eventual return to the North Atlantic they cool and the cycle begins again

1000 years for any cubic meter of water to
travel around the entire system

Question 21

Biological carbon pump

Answer 21

Half of the planet’s
biomass consist of phytoplankton.

When they get eaten, carbon is passed
through the food chain.

Helps form carbonate shells of plankton, which dissolve into the deep currents and get buried and compressed into limestone sediment.

Question 22

Air-sea gas exchange

Answer 22

CO2 from the atmosphere will naturally by dissolving into the water.
This process occurs on the surface of the oceans where CO2 reacts with water to form
carbonic acid

Question 23

Ocean acidification

Answer 23

Excess Co2 in the atmosphere dissolves into the ocean, lowering the pH, making it more acidic.

Negative chain affects mollusks, plankton and corals

Question 24

Physical pump

Answer 24

Oceanic circulation of water allowing the storage of carbon.

Colder water absorbs more Co2

(CO2 concentration is 10% higher in deep waters)

Question 25

Terrestrial Sequestration

Answer 25

Plants take carbon from the atmosphere to photosynthesise. Consumers eat plants and convert it into fats and proteins.

Microorganisms feed on waste material from plants and animals.

Decomposition is faster in tropical climates with high rainfall, temperatures and oxygen levels

Question 26

Diurnal flux

Answer 26

During the day, fluxes are positive from the atmosphere to the ecosystem (plants photosynthesising)

At night, fluxes are negative from the atmosphere to the ecosystem. (plants respiring releasing Co2 back into the atmosphere)

Question 27

Seasonal flux

Answer 27

In northern hemisphere, during winter, plants die and decay leading to high Co2 levels

In spring when plants grow and photosynthesise, Co2 levels drop