Carbon Cycle (1.4)

Carbon Sink

A reservoir that absorbs more carbon than it releases, lowering atmospheric CO₂

Carbon Source

A process or reservoir that releases more carbon than it stores, raising atmospheric CO₂

Short-Term Carbon Cycle

Rapid cycling of carbon between organisms and the atmosphere through photosynthesis and respiration

Long-Term Carbon Cycle

Slow cycling of carbon through sedimentation, burial, and fossil fuel formation over geologic time

Photosynthesis

Process where plants, algae, and phytoplankton take in CO₂ and convert it into glucose

Cellular Respiration

Process where organisms break down glucose using oxygen, releasing energy and CO₂

No Net Increase in Atmospheric Carbon

When photosynthesis and respiration balance, keeping CO₂ levels stable

Direct Ocean–Atmosphere Exchange

Fast movement of CO₂ between the ocean and the atmosphere by dissolving in and out

Ocean Acidification

Decrease in ocean pH caused by increased absorption of atmospheric CO₂

Sedimentation

Sinking and accumulation of dead marine organisms on the ocean floor as sediments

Burial

Long-term compression of sediments into sedimentary rock or fossil fuels

Sedimentary Rock

Long-term carbon reservoir formed from compressed sediments, such as limestone

Fossil Fuels

Coal, oil, and natural gas formed from buried organic matter over millions of years

Extraction

Human removal of fossil fuels from underground

Combustion

Burning fossil fuels to release energy, rapidly emitting CO₂

Deforestation

Cutting down trees, releasing stored carbon and reducing carbon uptake

Methane (CH₄)

Powerful greenhouse gas released mainly by animal agriculture

Carbon Cycle Imbalance

Fossil fuel combustion releases CO₂ faster than long-term processes can remove it