A-Level Geography: The Carbon Cycle KEY TERMS Flashcards
Carbon
One of the most chemically versatile of all the elements. Forms more compounds than any other element. It is found in all life forms in addition to sedimentary rocks, diamonds, graphite, coal and petroleum (oil and gas).
The carbon cycle
The complex process carbon undergoes as it is transformed from organic carbon (the form found in living organisms such as plants and trees) to inorganic carbon and back again.
Carbon Dioxide (CO2)
A gas found in the atmosphere, soils and oceans. We study this in the most detail.
Methane (CH4)
Gas is found in the atmosphere, soils and oceans and sedimentary rocks.
Calcium Carbonate (CaCO3)
A solid compound found in calcareous rocks, oceans and in the skeletons and shells of ocean creatures.
Hydrocarbons
Solids, liquids or gases are usually found in sedimentary rocks.
Bio-molecules
Complex carbon compounds are produced in living things. Proteins, carbohydrates, fats & oils and DNA are examples.
Gigatonne
The most common unit is used to measure carbon. 1 is equivalent to one billion tonnes.
Transfer/flux
Measure in gigatonnes/year (Gtc/yr). The movement of carbon between stores.
Anthropogenic CO2
Carbon dioxide is generated by human activity.
Biosphere
The total sum of all living matter. This can be divided into the terrestrial biosphere (3,170 GtC) and the oceanic biosphere.
Carbon sequestration
The capture of carbon dioxide from the atmosphere or capturing anthropogenic (human) CO2 from large-scale stationary sources like power plants before it is released into the atmosphere. Once captured, the CO2 gas (or carbon portion of the CO2) is put into long-term storage.
Carbon sink
A store of carbon absorbs more carbon than it releases.
Greenhouse Gases (GHGs)
Any gaseous compound in the atmosphere is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere.
Lithosphere
A rigid layer is made up of the uppermost part of the mantle and the crust. Carbon is distributed between the marine sediments (100 million GtC), soil organic matter (1500 GtC), fossil fuel deposits (4,100 GtC) and peat (250 GtC).
Weathering
The breaking down of rocks and other materials on the Earth’s surface by biological, chemical or mechanical processes.
Euphotic Zone
The upper layer of a body of water through which sunlight can penetrate and support photosynthesis. Contains approximately 900 GtC of carbon.
Twilight Zone
A layer of water under the sunlight zone extends to 3000 feet compliantly dark no light very high-pressure near-freezing temps no plant life. Contains approximately 37,100 GtC of carbon.
Living vegetation
19% of the carbon in the Earth’s biosphere is stored in plants (20% of this is stored in the Amazon rainforest). Much of this carbon is stored directly in the tissue of plants.
Plant litter
This is defined as the fresh, undecomposed and easily recognisable (by species and type) plant debris. This can be anything from leaves, cones, needles, twigs, bark, seeds, nuts etc. Leaf tissues account for 70% of the debris in forests.
Hummus
This originates from litter decomposition. It is a thick brown or black substance that remains after the most organic litter has decomposed. It gets dispersed through the soil by soil organisms such as earthworms.
Organic carbon
Relating mainly to carbon compounds derived from biological sources. Also refers to carbon sources other than simple carbonates and carbon dioxide, such as hydrocarbons.
Inorganic carbon
Carbon is extracted from ores and minerals e.g carbon dioxide, carbonic acid, bicarbonate anion, and carbonate.
Peat
An accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands or mires. It covers 4 million km2 or 3% of the land and freshwater surface of the planet; they occur on all continents. It is estimated that they store 250 GtC worldwide.