Carbon Cycle

Biogeochemical cycles

The movements of matter within and between ecosystems involving biological, geological, and chemical processes.

Reservoirs

Components of the biogeochemical cycle that contain matter, such as air, water, and organisms.

Source

A reservoir that releases atoms and molecules into the environment.

Sink

A reservoir that stores atoms and molecules.

Carbon

The most important element in living organisms, making up about 20% of their total body weight.

Carbon cycle

The movement of carbon around the biosphere among reservoir sources and sinks.

Fast part of the carbon cycle

Involves processes associated with living organisms that hold carbon for a short period, including photosynthesis and respiration.

Slow part of the carbon cycle

Involves carbon held in rocks, soils, or petroleum hydrocarbons.

Photosynthesis

The process by which plants and algae convert carbon dioxide and water into glucose and oxygen using solar energy.

Aerobic respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Decomposers

Organisms that break down dead material, returning CO2 to the water or air via respiration.

Carbon exchange

The process of carbon moving between the atmosphere and the ocean, balancing CO2 release and absorption.

Calcium carbonate (CaCO3)

A compound formed when CO2 combines with calcium ions in ocean water, contributing to sedimentation and burial.

Fossilization

The process by which organic matter becomes fossil fuels over time.

Steady state

A condition where a system’s input equals its output, resulting in no change over time.

Combustion

The process of burning fossil fuels, releasing carbon into the atmosphere as CO2 or into the soil as ash.

Greenhouse effect

The warming of the planet caused by gases in the atmosphere absorbing and re-emitting heat.

Human impact

The accelerated movement of fossilized carbon into the atmosphere, increasing atmospheric carbon levels.

Tree harvesting

The destruction of forests that increases CO2 levels in the atmosphere by releasing stored carbon.