Carbon Cycle Glossary

abiotic

non-living physical and chemical environmental factors that affect the ability of organism to survive and reproduce; examples include rainfall, temperature, soil nutrients, sunlight.

afforestation

reestablishing a forest on land that has been without forest for a very long time.

albedo

a measure of the reflectivity of a surface ranging from 0 to 1; albedo is calculated by taking the ratio of reflected radiation to incoming radiation, such that a surface that reflects 100% of light hitting it has an albedo of 1 and a surface that absorbs 100% of the light hitting it has an albedo of 0.

allometry and allometric coefficients

the study of relationships between growth and size of one portion an organism to the entire organism; foresters determine the allometric relationships of a species of tree by determining the diameter of several trees of one species, cutting them down, digging up the roots, drying everything out and then weighing the biomass of all the wood.

amplifying feedback loop

amplifies the original perturbation or change by increasing, speeding up or reinforcing the original perturbation or change; also called a positive feedback loop or reinforcing feedback loop.

autotroph

organisms capable of synthesizing their own food from inorganic substances using light or chemical energy.Green plants, algae, and certain bacteria are autotrophs.

balancing feedback loop

feedback in which an action produces a result that slows down and/or dampens an effect, tending to push a system towards stability; also called a negative feedback loop or a dampening feedback loop.

biogeochemical cycles

cycles of other chemical elements such as nitrogen, phosphorus, sulfur and iron that move into and out different components of the geosphere and biosphere.

biomass

mass of living or once living material.

biomolecule

organic carbon compounds produced in living things; examples include carbohydrates, lipids (fat, soils, waxes), and DNA.

biosphere

encompasses all the living things that exist in the atmosphere, hydrosphere and lithosphere.

biosynthesis

refers to the production of new organic carbon compounds by a living organism; simple carbon compounds can be modified, converted into other new carbon compounds or used to build large, complex macromolecules such as proteins and DNA.

biome

communities of plants and animals that are defined geographically and climatically. For example, rainforests are a biome defined as warm all year round with plenty of rain and sunlight, generally found near the equator with lush plant growth and a diversity of animals.

biotic

all organisms, the materials they produce and the processes they carry out that directly or indirectly affect an organism and its environment; examples include reproduction, parasitism, disease, predation, producing waste products, nitrogen fixation etc.

carbon fixation

the process by which photosynthetic organisms such as plants and algae turn inorganic carbon compounds (usually carbon dioxide) into organic carbon compounds (usually carbohydrate sugars such as glucose).

carbon cycle process (flux)

causes carbon to move from one reservoir to another; examples are photosynthesis, respiration and combustion.

carbon reservoir

a place in the Earth System where carbon is stored; examples include organisms, bodies of water, soil, rock, atmosphere, and fossil fuels.

carbon sink

carbon reservoir that absorbs more carbon than it releases; examples include carbon forests, soil and the ocean.

carbon source

a carbon reservoir that releases more carbon than it absorbs; fossil fuels extracted from deep within the ground are a carbon source.

causal connections

cause and effect relationships between parts of a system; a change in one part of a complex system can cause changes in other parts of the system.

cellulose

a long, fibrous carbohydrate (C₆H₁₂O₆) made by plants; wood and bark are made primarily out of cellulose.

CHNOPS

acronym for carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur atoms; 97% of organisms are made of just these six elements.

coccolithophores

tiny unicellular marine phytoplankton that live in large numbers throughout the upper layers of the ocean; build outer plates (shells) of limestone calcium carbonates (CaCO₃).

combustion

process of burning something; example is when a substance such as wood, coal and gas reacts with oxygen to produce carbon dioxide, water vapor, heat and energy.

covalent electron bond

a chemical bond that involves the sharing of electron pairs between atoms.

dampening feedback loop

slows down or reduces the original perturbation or change in a complex system tending to push a system towards stability; also called a negative feedback loop or dampening feedback loop.

deciduous trees

trees and other plants that seasonally lose their leaves.

decomposition

natural process of dead organisms being rotted or broken down into smaller bits; decomposers respire CO2 to the surrounding soil and air.

downwelling

occurs when surface waters converge (come together), pushing the surface water downwards; regions of low primary productivity because nutrients get used up and are not continuously resupplied by the cold, nutrient-rich water from below the surface.

evapotranspiration

the combination of the evaporation and transpiration processes in plants, both of which release moisture into the air; water is drawn up by the roots into the plants and some of this water evaporates from the leaves.

feedback

in ecosystems, an initial change in an environmental variable in a that causes changes in other variables that then influence the initial environmental change.

feedback loops

a complex system response to a change or perturbation in the system; initial change can be amplified (positive feedback) or dampened (negative feedback).

foraminfera

mostly microscopic, unicellular amoeboid protists that live in the ocean; produce shells of organic material, sediment grains, or calcium carbonate; can be found in just about every marine environment from the deep sea to shallow reefs, buried in sediment or floating in the water column.

gigaton (Gt)

one gigaton(Gt) is equivalent to 1,000,000,000 (one billion) metric tons; also written as gigatonnes; one gigaton is equivalent to one petagram.

glucose

a carbohydrate sugar (C6H12O6) produced by plants via photosynthesis; used for cellular respiration and for building plant structures.

greenhouse effect

natural phenomenon that warms the temperature of Earth's surface and lower atmosphere because greenhouse gases absorb and emit infrared radiation that would otherwise escape to outer space.

greenhouse gas

atmospheric gases that warm the temperature of Earth's lower atmosphere by absorbing and emitting infrared radiation that would otherwise escape to outer space; includes carbon dioxide, methane, water vapor, ozone nitrous oxide and CFCs.

gross primary productivity

amount of CO2 plants absorb from air to use for photosynthesis

hardwoods and softwoods/dt>

in general, hardwood comes from deciduous trees and has denser wood than softwood trees, which come from conifers.

heterotroph

organisms that cannot manufacture their own food and instead obtain their food and energy by taking in organic substances, usually plant or animal matter; animals, protozoans, fungi, and most bacteria are heterotrophs.

humification

formation of humus during the decomposition of organic matter in soils.

hydrocarbon

organic carbon compounds that are made of carbon and hydrogen atoms; oil, gas are examples.

ice age

any geological period in which long-term cooling takes place and ice sheets and glaciers exist.

ice core

a core sample that is typically drilled and removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from high mountain glaciers elsewhere.

in situ

in the original or natural position or site; example, data collected on site as opposed to in a lab.

infrared longwave radiation(IR)

lies between the visible and microwave portions of the electromagnetic spectrum; "near infrared" light is closest in wavelength to visible light and "far infrared" is closer to the microwave region of the electromagnetic spectrum; far infrared waves are thermal which we feel as heat.

inorganic carbon compound

a carbon compound that does not contain both carbon and hydrogen and tends to be simpler than organic compounds; examples include carbon dioxide (CO2) and carbonates (CaCO3).

insolation

the amount of solar radiation that reaches Earth's surface; the more the insolation, the higher the temperature; is affected by angle of the sun, distance between the sun and the earth, and duration of daylight.

interglacial

warm period within a glacial age.

ion

an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons

marine snow

its of organic carbon-containing material sinking from upper ocean waters to the deep ocean; includes bits and pieces of dead, decaying marine organisms, fecal matter, in addition to sand, soot, and other inorganic dust.

methanogens

microbes that produce methane instead of CO2 when they respire.

methanotrophs

bacteria that use the methane produced by methanogen bacteria for their energy and carbon source.

ocean microbial loop

refers to the small microscopic organisms in the ocean -- viruses, bacteria, the small phytoplankton and microzooplankton -- and the food web relationships between them.

ocean sediment cores

layers of ocean sediments that contain shells and fossils of marine organisms that died long ago, dust and other materials; varieties and concentration of certain fossil microorganisms record past changes in ocean temperature and composition; collected by scientists to reconstruct past paleoclimates

mitigate

make less severe or serious, slow down.

mycorrhizal fungi

fungi that live on and in the roots of plants and have a symbiotic relationship with plants, getting plant sugars for food in return for greatly enhancing the plant's ability to take up water and nutrients from the soil; fungi eat the sugars and then deposit carbon-containing residue in the surrounding soil.

negative feedback loop

an initial perturbation or change in a system causes a different type of change in another part of the system; example, an amplification of one environmental variable causes a dampening of a second environmental variable.

net carbon uptake

also called net primary production, net carbon uptake is the difference between the amount of carbon taken in via photosynthesis and the amount of carbon released via cell respiration.

net primary production (NPP)

the difference between the amount of carbon taken in via photosynthesis and the amount of carbon released via cell respiration.

organic carbon compounds

contain carbon atoms bonded to hydrogen atoms and and possibly other elements such as nitrogen or phosphorous; examples include proteins, carbohydrates, nucleic acids and fats, oils and waxes.

photon

discrete packet of energy (or quanta) associated with electromagnetic radiation (light). Photons associated with specific wavelengths and frequencies of electromagnetic radiation can be absorbed by molecules with matching frequencies.

photosynthesis

process whereby plants and algae use sunlight energy to make carbohydrate organic carbon compounds (such as glucose sugar ) from inorganic carbon dioxide (CO2) and water (H2O); plants immediately use some of their newly formed carbohydrate sugars for energy, growth, and maintenance.

phytoplankton

mostly microscopic, unicellular photosynthetic organisms that live in the upper sunlit layers of oceans and other bodies of water; mainly unicellular algae but also includes cyanobacteria.

phytoplankton bloom

takes place when a species of phytoplankton reproduces at a rapid rate, multiplying quickly in a short amount of time; many are temporary events that disappear after the source of the nutrients is gone or when conditions are no longer favorable.

positive feedback loop

an initial perturbation or change in a system that causes the same type of change in another part of the system; an example is when an amplification of one environmental variable causes an amplification of a second environmental variable.

proxy data

data that paleoclimatologists gather from natural recorders of climate variability, e.g., tree rings, ice cores, fossil pollen, ocean sediments, coral and historical data.

reforestation

re-establishing / planting forest on land that had recent tree cover.

reinforcing feedback loop

amplifies the original perturbation or change by increasing, speeding up or reinforcing the original perturbation or change in a complex system; also called a positive feedback loop or ramplifying feedback loop.

respiration

cellular process whereby organisms convert carbohydrates (glucose sugar), water and oxygen into energy, carbon dioxide and water; also referred to as cell respiration or cellular respiration.

soil nutrients

nutrients in soil that are essential for plant growth; the most important soil nutrients include nitrogen, phosphorus, magnesium and sulfur.

soil organic carbon (SOC)

the amount of carbon contained in soil organic matter (SOM).

soil organic matter (SOM)

the organic matter component of soil, consisting of plant and animal residues at various stages of decomposition, cells and tissues of soil organisms, and substances synthesized by soil organisms.

soil respiration

carbon dioxide produced when organisms living in soil carry out cell respiration; includes respiration by soil bacteria, fungi and fauna, and the cells of plant roots.

solar shortwave radiation

energy radiated from the Sun mainly in the form of visible light, with small amounts of ultraviolet and infrared radiation; solar radiation is usually referred to as shortwave radiation while infrared radiation is referred to as long wave radiation.

time series data

data usually taken at equal time intervals or a period of time.

tundra

vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen.

upwelling

Upwelling currents occur when surface waters diverge (move apart), enabling upward movement of water; bring water to the surface that is enriched with nutrients important for primary productivity (phytoplankton growth) that in turn supports richly productive marine ecosystems.