Notes on Carbon Cycle Processes

Photosynthesis

• Before: Carbon exists as CO₂ in the atmosphere.

• During: Plants absorb CO₂, convert to glucose, release O₂.

• After: Carbon stored as glucose in plants.

Cellular Respiration

• Before: Carbon stored in glucose in tissues.

• During: Organisms break down glucose, release energy, produce CO₂.

• After: Carbon released back as CO₂.

Combustion (e.g., burning fossil fuels)

• Before: Carbon in fossil fuels.

• During: Burning releases CO₂.

• After: Carbon from fuels becomes atmospheric CO₂.

Fossil Fuel Extraction

• Before: Carbon in fossil fuels underground.

• During: Extraction and energy use.

• After: Carbon released during combustion.

Cement Manufacturing

• Before: Carbon in limestone.

• During: Heating limestone releases CO₂.

• After: Carbon from limestone becomes atmospheric CO₂.

Driving Gasoline-Powered Car

• Before: Carbon in gasoline.

• During: Burning gasoline emits CO₂.

• After: Carbon emitted into the atmosphere.

Deforestation

• Before: Carbon in trees.

• During: Cutting trees releases stored carbon.

• After: Carbon released into the atmosphere.

Planting New Trees

• Before: Carbon in atmosphere as CO₂.

• During: Trees absorb CO₂, store carbon.

• After: Carbon sequestered in growing trees.

Volcanism

• Before: Carbon in Earth’s crust.

• During: Volcanic eruptions release CO₂.

• After: Carbon becomes atmospheric CO₂.

Carbon Capture and Storage (CCS)

• Before: Carbon emitted from industrial processes.

• During: CCS captures CO₂ emissions, stores underground.

• After: Carbon sequestered underground.