Carbon Cycle (Edexcel A Level Geography): Flashcards
Exam code: 9GE0
1/410Still learning
Know0
- FrontCarbon Cycle
Define carbon store.
Was this flashcard helpful?
Cards in this collection (41)
Define carbon store.
A carbon store is a reservoir where carbon is held for a period of time, such as the atmosphere, oceans, rocks or living organisms.
Define carbon flux.
A carbon flux is the rate of transfer of carbon between stores, usually measured in petagrams or gigatonnes of carbon per year.
Name the five spheres where carbon is stored.
Carbon is stored in the atmosphere, hydrosphere, lithosphere, biosphere and cryosphere.
What is meant by a carbon source and sink?
A source adds carbon to the atmosphere, while a sink removes and stores carbon from the atmosphere.
True or False?
The carbon cycle is an open system with changing total carbon.
False.
The carbon cycle is a closed system where total carbon is constant and finite, though it moves between different stores.
Define outgassing.
Outgassing is the release of carbon dioxide that was dissolved, trapped, frozen or absorbed in rock back into the atmosphere.
Where does volcanic outgassing commonly occur?
Outgassing occurs at volcanic plate boundaries, in non‑volcanic geothermal areas like geysers, and from fractures in the Earth's crust.
True or False?
Volcanoes emit more carbon dioxide annually than fossil fuels.
False.
Volcanoes emit about 0.15–0.26 Gt
per year, whereas fossil fuel use emits around 35 Gt per year.Define geological carbon store.
A geological carbon store is carbon locked in rocks and sediments, mainly limestone, shale, coal, oil and natural gas, often for millions of years.
How is limestone formed as a carbon store?
Limestone forms when corals and plankton shells accumulate on the ocean floor, become layered, and are lithified into sedimentary rock.
How do coal, oil and gas form instead of shale?
They form when organic matter accumulates faster than it decays, so buried organic carbon becomes coal, oil or natural gas rather than shale.
Carbon can take between and years to move between rocks, soil, ocean and atmosphere.
Carbon can take between 100 million and 200 million years to move between rocks, soil, ocean and atmosphere.
The gas released by volcanic eruptions is relatively compared to emissions of carbon dioxide.
The gas released by volcanic eruptions is relatively insignificant compared to human emissions of carbon dioxide.
Define biological carbon store in soils.
Carbon held as dead organic matter in soils for years to centuries, especially in cold climates and wetlands.
How does litter fall transfer carbon to soils?
When plants die or shed leaves, this litter falls to the ground, adding organic carbon to the soil store.
Clay-rich soils have carbon content than sandy soils because clay carbon from decomposition.
Clay-rich soils have higher carbon content than sandy soils because clay protects carbon from decomposition.
How does climate affect soil organic carbon storage?
Warmer, wetter climates increase decomposition, while high rainfall can increase potential carbon storage compared with the same soil in drier areas.
True or False?
Most soil carbon is stored for only a few days.
False.
A large share of soil organic carbon is stored for years to centuries, especially in cold or waterlogged environments.
Define carbon sequestration.
The movement of carbon into carbon stores such as oceans, vegetation or soils, reducing carbon dioxide in the atmosphere.
What role do phytoplankton play in carbon sequestration?
They carry out photosynthesis, converting CO2 into organic matter, forming a biological pump that moves carbon from surface waters to deeper ocean stores.
Describe the physical carbon pump in oceans.
CO2 diffuses into surface water, then downwelling currents and thermohaline circulation transport dissolved carbon to intermediate and deep ocean stores.
The carbonate pump relies on inorganic carbon and forms long-term stores such as .
The carbonate pump relies on inorganic carbon sedimentation and forms long-term stores such as limestone.
True or False?
Oceans are the largest carbon store on Earth.
True.
About 93% of CO2 is stored in oceans as dissolved carbon, undersea algae, plants and coral.
Define terrestrial sequestration.
The uptake and storage of carbon by land ecosystems (plants, soils, decomposers) over short timescales of seconds to years.
In which climates is decomposition fastest and slowest?
It is fastest in tropical climates with high temperature, rainfall and oxygen, and slowest in cold, dry or low-oxygen conditions.
Carbon fluxes in biomes vary (day–night) and (spring–summer).
Carbon fluxes in biomes vary diurnally (day–night) and seasonally (spring–summer).
Define natural greenhouse effect.
The natural greenhouse effect is the warming of Earth as greenhouse gases trap outgoing long-wave radiation, maintaining temperatures that support life.
What type of radiation primarily drives the Earth\'s climate system?
The Earth\'s climate is driven mainly by incoming shortwave solar radiation from the Sun.
True or False?
Increasing atmospheric carbon dioxide strengthens the greenhouse effect.
True.
Higher carbon dioxide levels trap more long-wave radiation, causing global temperatures to rise.
Around % of incoming solar radiation is reflected by the atmosphere and surface.
Around 31 % of incoming solar radiation is reflected by the atmosphere and surface.
The balanced carbon cycle helps regulate global and the cycle.
The balanced carbon cycle helps regulate global temperature and the hydrological cycle.
Define photosynthesis in the carbon cycle.
Photosynthesis is the process where plants and phytoplankton absorb carbon dioxide and use light to produce biomass and release oxygen.
Where is net primary productivity (NPP) highest on Earth?
NPP is highest in warm, wet regions like tropical rainforests and in shallow ocean waters rich in light and nutrients.
Soil health depends on organic carbon and .
Soil health depends on organic carbon inputs and outputs.
A major threat to soil carbon storage is , which removes carbon-rich surface layers.
A major threat to soil carbon storage is soil erosion, which removes carbon-rich surface layers.
How does terrestrial photosynthesis influence atmospheric carbon dioxide?
Terrestrial photosynthesis removes carbon dioxide from the atmosphere, helping keep concentrations relatively constant and regulating average global temperatures.
Define slow carbon cycling.
Slow carbon cycling is the long-term movement of carbon through rocks, deep oceans and fossil fuels, operating over hundreds of thousands to millions of years.
How has fossil fuel combustion changed the carbon cycle?
Burning fossil fuels moves carbon from slow to fast carbon cycling, increasing atmospheric carbon dioxide and disrupting the carbon balance.
True or False?
The IPCC links rising sea levels to fossil fuel emissions.
True.
The IPCC reports connect higher greenhouse gas concentrations from fossil fuels to global warming and sea-level rise.
The North Atlantic Drift helps keep UK winters about °C than otherwise.
The North Atlantic Drift helps keep UK winters about 5 °C warmer than otherwise.
Marine ecosystems face ocean acidification, lower levels and changing due to warming.
Marine ecosystems face ocean acidification, lower oxygen levels and changing food chains due to warming.
Sign up to unlock flashcards
or