Carbon EQ1 6-8 Markers

Explain how global carbon is locked in stores of different sizes

There are two types of global stores of carbon, determined by the recycling time: short-term and long-term. Terrestrial ecosystems (short-term) involves CO₂ being taken from the atmosphere by plants through photosynthesis, and being stored organically within plant biomass. Atmospheric storage (short-term) involves C0₂ and CH₄ storing carbon as greenhouses gases with a lifetime of up to 100 years. Oceanic (surface) (short-term) involves CO₂ being taken from atmosphere by phytoplankton through photosynthesis; and the dissolution of CO₂ into the ocean to form carbonic acid (e.g. oceanic carbon store stores 50 times more carbon than atmospheric carbon store). Terrestrial soil (short-term) involves micro-organisms decomposing plant biomass to CO₂. Oceanic (deep) (long-term) involves most carbon being dissolved in organic carbon. Terrestrial geological (long-term) involves carbon being stored within sedimentary rocks.

Explain the geological formation of carbon

Terrestrial carbon within the lithosphere is released into the atmosphere as C0₂ through volcanic out-gassing. Carbonic acid is produced as CO₂ within the atmosphere combines with rainfall, dissolving carbonate rocks through chemical weathering. Rivers transport carbon and calcium sediment to oceans to be deposited. Carbon in shells and skeletons from animals, and organic matter from plants sink to seabed when animals and plants die, building up a strata of limestone, chalk and coal. Calcium ions combine within bicarbonate ions to calcium carbonate and precipitate, calcite sediment is converted to limestone through deposition. The presence of intense heating along subduction zones metamorphoses sedimentary rocks, creating metamorphic rocks that releases CO₂.

Explain the geological processes that are responsible for the release of carbon into the atmosphere

Carbonic acid is produced as CO₂ within the atmosphere combines with rainfall, dissolving carbonate rocks through chemical weathering. Rivers transport carbon and calcium sediment to oceans to be deposited. Carbon in shells and skeletons from animals, and organic matter from plants sink to seabed when animals and plants die, building up a strata of limestone, chalk and coal. Calcium ions combine within bicarbonate ions to calcium carbonate and precipitate, calcite sediment is converted to limestone through deposition. The presence of intense heating along subduction zones metamorphoses sedimentary rocks, creating metamorphic rocks that releases CO₂. Terrestrial carbon within the lithosphere is released into the atmosphere through volcanic out-gassing, with carbonate rocks being dragged into the mantle by rising magma at subduction zones. Volcanic out-gassing at constructive plate boundaries and at mid-ocean ridges tend to be less explosive with less carbon emitted.

Explain how biological processes sequester carbon on land and in the oceans

Biological processes sequester carbon as part of oceanic sequestration and terrestrial sequestration. The biological pump (within oceanic sequestration) involves the organic sequestration of CO₂ to oceans by phytoplankton that convert atmospheric carbon into organic matter through photosynthesis, with phytoplankton being most productive in shallow waters of continental shelves and in nutrient upwelling locations. Carbon is passed along the food chain by consumer fish and zooplankton. Most carbon is recycled in surface waters within only 0.01% of carbon reaching sea flood as dead phytoplankton sink, decomposing or undergoing sedimentation. Terrestrial sequestration involves primary producers taking carbon from atmosphere through photosynthesis. As consumer animals eat plants, carbon from plants becomes part of fats and proteins of animals. Micro-organisms and detritus feeders feed on waste material from animals, becoming party of such organisms, with faster decay in more resistant structures and in tropical climates.

Explain how photosynthesis plays an important role in regulating the composition of the atmosphere

Photosynthesis involves the conversion of atmospheric inorganic carbon into an organic form within biotic organisms using light by organisms, occurring as part of oceanic sequestration (biological pump) and terrestrial sequestration. The biological pump within oceanic sequestration involves the organic sequestration of CO₂ by phytoplankton that converts atmospheric carbon into organic matter through photosynthesis with oceanic stores storing 50 times more carbon than the atmosphere and the biological pump sequestering 5-15 Gt of carbon to oceans per annum. In this way, carbon is removed the atmosphere and passed to the carbonate and physical pumps that maintain a dynamic equilibrium - with more carbon being sequestered by phytoplankton through algal blooms in the Arctic as the Arctic warms. Terrestrial sequestration involves primary producers taking carbon from the atmosphere through photosynthesis for growth, contributing to a positive feedback loop as more vegetation grows, sequestering more carbon from the atmosphere; carbon is passed along the food chain, with carbon from plants becoming parts of fats and proteins of animals.

For one named ecosystem, explain why threats to it may have an impact on the carbon cycle

The Amazon Rainforest in South America is experiencing deforestation. Fewer trees mean that more CO₂ is released into the atmosphere, contributing to the enhanced greenhouse effect that increases average annual temperatures; such higher temperatures can contribute to increased occurrence of drought and wildfires where more trees die, decompose and burn, releasing CO₂ within a positive feedback loop. Fewer trees mean that less CO₂ is sequestered from the atmosphere (terrestrial sequestration) through photosynthesis, contributing to higher concentrations of C0₂ in the atmosphere, especially as the Amazon Rainforest acts as a massive carbon sink, accounting for 17% of terrestrial ecosystem sequestration, disrupting the nature dynamic equilibrium.

Using the diagram, explain why these carbon pumps are important in the carbon cycle

There are three pumps involved in oceanic sequestration: biological, carbonate and physical. The biological pump involves the organic sequestration of CO₂ to oceans by phytoplankton that convert inorganic atmospheric carbon into organic matter through photosynthesis, especially in shallow waters of continental shelves and in nutrient upwelling locations. Carbon is passed along the food chain by consumer fish and zooplankton, releasing CO₂ into water through respiration. Such CO₂ within the ocean is used within the carbonate pump, involving marine organisms utilising calcium carbonate (CaCO₃) to create hard outer shells and inner skeletons, enabling more CO₂ to dissolve into the oceans from the atmosphere (dynamic equilibrium). Shells and inner skeletons dissolve before reaching sediment seafloor when organisms die and sink, becoming part of the deep ocean currents; these shells that do not dissolve build up on the seafloor to form sedimentary rocks. Within the physical pump, there are large spatial differences in CO₂ within oceans, with colder water having a greater potential for CO₂ to be absorbed compared to warmer waters that release CO₂ into the atmosphere. The thermohaline current transports waters from the Tropics to Polar regions where water cools and absorbs more CO₂ from the atmosphere. At high-latitude and Arctic zones with deep oceans, higher-density cool water sinks, transferring CO₂ at the surface downwards, enabling more CO₂ to be absorbed from the atmosphere.

Explain the implications of an increase in the combustion of fossil fuels

Alterations to the carbon balance involves the increased concentrations of CO₂ in the atmosphere store without any corresponding increase in natural sinks, including terrestrial ecosystems; altering carbon pathways as more carbon is released to the atmosphere. Changes to climate involves rising concentrations of atmospheric CO₂ increasing global temperatures, contributing to warmer annual temperatures and higher annual precipitation. Arctic amplification involves a positive feedback loop as melting permafrost release CO₂ and CH₄ that enhances the greenhouse effect, contributing to increased warming of tundra surface and ocean waters with melting permafrost. Alterations to the hydrological cycle may involve less precipitation in the form of snow and more precipitation in some places, with the melting of snow and ice from surface stores.

Explain how fossil fuel consumption may alter the carbon cycle

Fossil fuel consumption involves the burning of natural stores within the lithosphere (e.g. coal, natural gas) that releases CO₂ into the atmosphere. Fossil fuel consumption may alter the carbon balance as increased concentrations of CO₂ in the atmosphere store without any corresponding increase in natural sinks, including terrestrial ecosystems, altering carbon pathways as more carbon is released in the atmosphere. Rising concentrations of CO₂ contributes to an enhanced greenhouse effect that raises the average annual temperatures, contributing to wildfires and droughts that involves the death, decomposition and burning of forests, releasing CO₂ into the atmosphere from terrestrial ecosystems (e.g. tropical rainforests account for 30% of net primary productivity (NPP)). These warmer annual temperatures contribute to arctic amplification that involves a positive feedback loop as melting permafrost release CO₂ and CH₄ that enhances the greenhouse effect, contributing to further increased warming of tundra, disrupting the dynamic equilibrium.

Explain the importance of fluxes to the carbon cycle

Terrestrial sequestration involves CO₂ being taken in by plants through photosynthesis is important to maintain terrestrial life as carbon is passed along the food chain for growth in the form of fats and proteins in consumer animals. Oceanic sequestration and terrestrial sequestration involve CO₂ being taken into the oceans or plants respectively through photosynthesis, acting as a 'carbon sink' that reduces the greenhouse effect to maintain global temperatures necessary for life, preventing excessive increases that would contribute to climate change - especially as more CO₂ is released into the atmosphere through the burning of fossil fuels. Fluxes, oceanic and terrestrial sequestration, maintain the dynamic equilibrium of gases within the atmosphere.

Explain the significance of carbon sequestration

Biological processes sequester carbon as part of oceanic sequestration and terrestrial sequestration. The biological pump (within oceanic sequestration) involves the organic sequestration of CO₂ to oceans by phytoplankton that convert atmospheric carbon into organic matter through photosynthesis; in this way, the oceans act as a 'carbon sink' that reduces the greenhouse effect, preventing extreme rises in temperature as fossil fuels are burned. Terrestrial sequestration involves primary producers taking carbon from atmosphere through photosynthesis. As consumer animals eat plants, carbon from plants becomes part of fats and proteins of animals. Micro-organisms and detritus feeders feed on waste material from de animals, becoming part of such organisms, with faster decay in more resistant structures and in tropical climates. In this way, carbon sequestration can reduce the greenhouse effect by maintaining a dynamic equilibrium between different carbon stores.

Explain why a balanced carbon cycle is important for sustaining other Earth systems

An unbalanced carbon cycle involves an enhanced greenhouse effect as atmospheric gases (CO₂ and CH₄) trap infrared radiaton within the Earth, preventing such radiation from reflecting from the surface back into space. A balanced carbon cycle is important to maintain the distribution of temperature and precipitation. Oceanic sequestration and terrestrial question ensure a dynamic equilibrium of atmospheric gases in the atmosphere that reduces the greenhouse effect maintaining a constant temperature necessary for oceanic and terrestrial organisms. An unbalanced carbon cycle would alter the hydrological cycle as more CO₂ is released into the atmosphere without a corresponding increase in natural sinks, contributing to less precipitation in the form of snow and more precipitation in some places, with the melting of snow and ice from surface stores.

Explain why it is important that the carbon cycle remains in equilibrium

A carbon cycle in equilibrium involves an enhanced greenhouse effect as atmospheric gases (CO₂ and CH₄) trap infrared radiation within the Earth, preventing such radiation from reflecting from the surface back into space. A carbon cycle in equilibrium important to maintain the distribution of temperature and precipitation. Oceanic sequestration and terrestrial question ensure a dynamic equilibrium of atmospheric gases in the atmosphere that reduces the greenhouse effect maintaining a constant temperature necessary for oceanic and terrestrial organisms. A carbon cycle in equilibrium alter the hydrological cycle as more CO₂ is released into the atmosphere without a corresponding increase in natural sinks, contributing to less precipitation in the form of snow and more precipitation in some places, with the melting of snow and ice from surface stores.

Explain why the proportions of vegetation and soil as carbon stores vary between biomes

The capacity of soil to store organic carbon is determined by: climate, soil type, and management and use of soils. Climate affects plant growth; rapid decomposition occurs at higher temperatures or under anaerobic waterlogged conditions. Regions with higher precipitation and lower temperatures have an increased potential carbon storage than soils in regions with lower precipitation and higher temperatures (e.g. soils in cold regions stores 800 tonnes per hectare). Soil type involves clay-rich soils have a higher carbon content than sandy soils, protecting carbon from decomposition in which carbon would be emitted to atmosphere through respiration). Management and use of soils involves the cultivation and disturbance of soils that releases carbon (e.g. 40-90 billion Gt of carbon lost from soils since 1850).

Explain the significance of soil in the carbon cycle

When dead animals and plants die, micro-organisms and detritus feeders feed on waste material from these animals in the soil, releasing carbon into CO₂ into the atmosphere through respiration. Terrestrial sequestration involves primary producers taking carbon from the atmosphere through photosynthesis, becoming part of the plant. As consumer animals eat plants, carbon from plants becomes part of fats and proteins of animals. Micro-organisms and detritus feeders feed on waste material from animals, become part of such organisms, with faster decay in more resistant structure and in tropic climates. Dead animals and plants are buried and converted into fossil fuels, being burned and released into atmosphere as CO₂.

Explain the potential interruptions to the carbon cycle caused by the destruction of rainforests

The Amazon Rainforest in South America is experiencing deforestation. Fewer trees mean that more CO₂ is released into the atmosphere, contributing to the greenhouse effect that increases average annual temperatures; such higher temperatures can contribute to increased occurrence of drought and wildfires where more trees die, decompose and burn, releasing CO₂ within a positive feedback loop. Fewer trees mean that less CO₂ is sequestered from the atmosphere (terrestrial sequestration) through photosynthesis, contributing to higher concentrations of C0₂ in the atmosphere, especially as the Amazon Rainforest acts as a massive carbon sink, accounting for 17% of terrestrial ecosystem sequestration.

Explain the processes that move carbon between stores

The biological pump transfers CO₂ from the atmosphere to the oceanic store (hydrosphere) via the photosynthesis of phytoplankton using light. Volcanic outgassing at subduction zones and hotpots releases CO₂ and CH₄ from the lithosphere to the atmosphere. Terrestrial sequestration transfers CO₂ from the atmosphere to terrestrial ecosystems (biosphere) via the photosynthesis of terrestrial trees using light. The decay and decomposition of dead matter micro-organisms releases CO₂ via respiration from the lithosphere to the atmosphere. Combustion of fossil fuels transfers CO₂ from the lithosphere to the atmosphere. Deforestation transfers CO₂ from terrestrial ecosystems to the atmosphere.

Explain the contributions of volcanic activity to the composition of the atmosphere in the past and present

Volcanic activity in the past and present has released carbon into the atmosphere through volcanic out-gassing, involving the release of CO₂ and CH₄ dissolved or stored following changes in heat or pressure, including during metamorphoses. Volcanic out-gassing occurs at: active volcanic zones, places with no current volcanic activity (e.g. Yellowstone National Park) and fractures in the Earth's crust. The eruption of Mount Pinatubo released 42 million tonnes of CO₂ at a subduction zone in 1991.

Explain how natural processes can increase or decrease the amount of carbon dioxide in the atmosphere

One natural process that would decrease the amount of CO2 in the atmosphere would be photosynthesis (Plants and Phytoplankton). This process would involve taking CO2 from the atmosphere, being sequestered by plants and phytoplankton to produce oxygen, essential to sustain life. The process that would be opposite to this is respiration (Plant, Phytoplankton and Soil) which takes in oxygen from the atmosphere and returns CO2, hence increasing the concentration of carbon dioxide. Another process would be volcanic outgassing, where carbon stored in the lithosphere is released via volcanic eruptions, hence increasing carbon dioxide concentration in the atmosphere.

Explain the importance of geological carbon stores in balancing the carbon cycle

Terrestrial geological carbon stores involve the storage of carbon in sedimentary rocks (e.g. limestone); these stores store up to 100,000,000 PgC of carbon, a long-term store - the highest of any carbon store, acting as a huge 'carbon sink' to take in carbon from the atmosphere to maintain a dynamic equilibrium in the atmosphere and reduce the greenhouse effect as less infrared radiation is reflected back into earth by CO₂ and CH₄. Terrestrial geological carbon stores involves very slow recycling over millennia that means carbon is not quickly released back into the atmosphere, maintaining a dynamic equilibrium in the atmosphere and reduce the greenhouse effect.

Explain how carbon is stored during the diagenesis of sedimentary rocks

Carbonic acid is produced as CO₂ within the atmosphere combines with rainfall, dissolving carbonate rocks through chemical weathering. Rivers transport carbon and calcium sediment to oceans to be deposited. Carbon in shells and skeletons from animals, and organic matter from plants sink to seabed when animals and plants die, building up a strata of limestone, chalk and coal. Calcium ions combine within bicarbonate ions to calcium carbonate and precipitate, calcite sediment is converted to limestone through deposition. The presence of intense heating along subduction zones metamorphoses sedimentary rocks, creating metamorphic rocks that releases CO₂. At subduction zones, carbon is recycled as sedimentary rocks are pulled into the mantle by rising magma.

Explain how human activity has released carbon from sedimentary rocks

Human activity has released CO₂ from the burning of fossil fuels, including coal and natural gas, that were formed through the metamorphoses of sedimentary rocks such as limestone. Higher concentrations of CO₂ in the atmosphere means that precipitation may be higher in some regions; such precipitation combines with CO₂ to form carbonic acid that dissolves sedimentary rocks to carbon and calcium sediments.

Explain how tectonic situations release carbon dioxide into the atmosphere

Volcanic activity in the past and present has released carbon into the atmosphere through volcanic out-gassing, involving the release of CO₂ and CH₄ dissolved or stored following changes in heat or pressure, including during metamorphoses. Volcanic out-gassing occurs at: active volcanic zones, places with no current volcanic activity (e.g. Yellowstone National Park) and fractures in the Earth's crust. The eruption of Mount Pinatubo released 42 million tonnes of CO₂ at a subduction zone in 1991.

Explain how geological processes store carbon for a long time period

Terrestrial carbon within the lithosphere is released into the atmosphere as C0₂ through volcanic out-gassing. Carbonic acid is produced as CO₂ within the atmosphere combines with rainfall, dissolving carbonate rocks through chemical weathering. Rivers transport carbon and calcium sediment to oceans to be deposited. Carbon in shells and skeletons from animals, and organic matter from plants sink to seabed when animals and plants die, building up a strata of limestone, chalk and coal. Calcium ions combine within bicarbonate ions to calcium carbonate and precipitate, calcite sediment is converted to limestone through deposition in the deep ocean, involving very slow cycling of carbon, storing up to 38,000 PgC of carbon. Sedimentation of dead animal and plants on land stores up to 100,000 PgC of carbon, involving very slow cycling over millennia as there is no exposure to atmospheric gases (O₂ and CO₂) that would release carbon from stores into atmosphere; carbon remains in sedimentary rocks until metamorphosis under heat and pressure.

Explain how the thermohaline circulation transfers carbon globally and between the atmosphere, ocean and seabed

The thermohaline circulation is a vital component of the global ocean CO₂ and nutrient cycles (physical pump). CO₂ in oceans is mixed much more slowly with large spatial differences in CO₂ concentration. Colder water has more potential for CO₂ to be dissolved to form carbonic acid and by phytoplankton through photosynthesis (e.g. more CO₂ at polar oceans than tropical oceans). Warm tropical oceans release CO₂ to the atmosphere, and colder high-latitude oceans take in CO₂ from the atmosphere (e.g. twice as much CO₂ dissolve into cold polar waters than in warm tropical waters). As thermohaline circulation move waters from Topics to poles, water cools and absorbs more CO₂ from atmosphere. High-latitude and Arctic zones with deep oceans have higher-density, cooler water, transferring CO₂ at the surface downwards.

Explain how plants help to maintain a balance in the carbon cycle

Terrestrial sequestration involves primary producers taking CO₂ from atmosphere through photosynthesis using sunlight for growth. Plants release CO₂ back into the atmosphere through respiration. In this way, the dynamic equilibrium within the atmosphere is maintained as the concentration of C0₂ in the atmosphere remains relatively stable, with the amount of CO₂ taken in during photosynthesis and released during respiration is relatively equal; also maintaining balance within terrestrial ecosystem stores as the amount of CO₂ taken in during photosynthesis and released during respiration is relatively equal.

Explain the role of oceans in the carbon cycle

There are three pumps involved in oceanic sequestration: biological, carbonate and physical. The biological pump involves the organic sequestration of CO₂ to oceans by phytoplankton that convert inorganic atmospheric carbon into organic matter through photosynthesis, especially in shallow waters of continental shelves and in nutrient upwelling locations. Carbon is passed along the food chain by consumer fish and zooplankton, releasing CO₂ into water through respiration. Such CO₂ within the ocean is used within the carbonate pump, involving marine organisms utilising calcium carbonate (CaCO₃) to create hard outer shells and inner skeletons, enabling more CO₂ to dissolve into the oceans from the atmosphere (dynamic equilibrium). Shells and inner skeletons dissolve before reaching sediment seafloor when organisms die and sink, becoming part of the deep ocean currents; these shells that do not dissolve build up on the seafloor to form sedimentary rocks. Within the physical pump, there are large spatial differences in CO₂ within oceans, with colder water having a greater potential for CO₂ to be absorbed compared to warmer waters that release CO₂ into the atmosphere. The thermohaline current transports waters from the Tropics to Polar regions where water cools and absorbs more CO₂ from the atmosphere. At high-latitude and Arctic zones with deep oceans, higher-density cool water sinks, transferring CO₂ at the surface downwards, enabling more CO₂ to be absorbed from the atmosphere.

Explain one reasons why the Arctic is called a barometer for climate change

The Arctic consists of frozen permafrost where there is not enough infrared radiation to raise temperatures enough to melt such permafrost. Climate change involves the release of CO₂ and CH₄ into the atmosphere through the burning of fossil fuels that contribute to the greenhouse effect, reflecting infrared radiation back into the Earth and preventing such radiation from escaping into space, increasing global temperatures. Arctic amplification involves a positive feedback loop as melting permafrost release CO₂ and CH₄ that enhances the greenhouse effect, contributing to increased warming of tundra surface and ocean waters with melting permafrost.

Explain the impact of the changing global consumption of fossil fuels on the

carbon cycle

Fossil fuel consumption involves the burning of natural stores within the lithosphere (e.g. coal, natural gas) that releases CO₂ into the atmosphere. Fossil fuel consumption may alter the carbon balance as increased concentrations of CO₂ in the atmosphere store without any corresponding increase in natural sinks, including terrestrial ecosystems, altering carbon pathways as more carbon is released in the atmosphere. Rising concentrations of CO₂ contributes to an enhanced greenhouse effect that raises the average annual temperatures, contributing to wildfires and droughts that involves the death, decomposition and burning of forests, releasing CO₂ into the atmosphere from terrestrial ecosystems (e.g. tropical rainforests account for 30% of net primary productivity (NPP)). These warmer annual temperatures contribute to arctic amplification that involves a positive feedback loop as melting permafrost release CO₂ and CH₄ that enhances the greenhouse effect, contributing to further increased warming of tundra, disrupting the dynamic equilibrium.

Explain the role of the carbon pumps in regulating the carbon cycle

There are three pumps involved in oceanic sequestration: biological, carbonate and physical. The biological pump involves the organic sequestration of CO₂ to oceans by phytoplankton that convert inorganic atmospheric carbon into organic matter through photosynthesis, especially in shallow waters of continental shelves and in nutrient upwelling locations. Carbon is passed along the food chain by consumer fish and zooplankton, releasing CO₂ into water through respiration. Such CO₂ within the ocean is used within the carbonate pump, involving marine organisms utilising calcium carbonate (CaCO₃) to create hard outer shells and inner skeletons, enabling more CO₂ to dissolve into the oceans from the atmosphere (dynamic equilibrium). Shells and inner skeletons dissolve before reaching sediment seafloor when organisms die and sink, becoming part of the deep ocean currents; these shells that do not dissolve build up on the seafloor to form sedimentary rocks. Within the physical pump, there are large spatial differences in CO₂ within oceans, with colder water having a greater potential for CO₂ to be absorbed compared to warmer waters that release CO₂ into the atmosphere. The thermohaline current transports waters from the Tropics to Polar regions where water cools and absorbs more CO₂ from the atmosphere. At high-latitude and Arctic zones with deep oceans, higher-density cool water sinks, transferring CO₂ at the surface downwards, enabling more CO₂ to be absorbed from the atmosphere