Notes on the Carbon Cycle

The Carbon Cycle

Overview of the Carbon Cycle

• The carbon cycle is a natural process that recycles carbon atoms, essential to life.

• Key question: Where does carbon go?

Carbon Cycle Game Instructions

• Role: Participants take on the identity of a carbon atom.

• Game Mechanics:

  • Start at a selected station (atmosphere, plants, etc.).

  • Roll a die to determine movement among stations.

  • Record processes that lead to new locations.

  • Stay at one station for a max of 3 turns before rolling again.

  • After completing the journey, draw your carbon cycle.

Carbon Cycle: Storages & Flows

• Carbon Stores/Pools: Locations where carbon resides.

  • Atmosphere: Exists mainly as CO₂.

  • Plants/Animals: Carbon is stored in biomolecules.

  • Soil/Rocks: Contains carbonate minerals.

  • Oceans: Carbon is dissolved in water or as sediment at the ocean floor.

  • Fossil Fuels: Composed of fossilized carbon (oil, coal).

• Processes/Flows: Movements of carbon between stores.

  • Combustion: Burning of fossil fuels releases carbon into the atmosphere.

  • Fossilization: Carbon from plants/animals becomes fossil fuels.

  • Photosynthesis: Plants absorb carbon from the atmosphere.

  • Respiration: Release of carbon back into the atmosphere by organisms.

  • Feeding: Transfer of carbon from plants/animals to animals.

  • Sedimentation: Carbon sinks from surface oceans to deep oceans.

  • Diffusion: Movement of CO₂ between the atmosphere and oceans.

  • Decomposition: Breakdown of organic matter releases carbon into soil or atmosphere.

  • Volcanic Eruptions: Releases carbon from rocks into the atmosphere.

  • Carbon Fixation: Process by which plants incorporate CO₂ for photosynthesis.

Visual Representation of the Carbon Cycle

• Drawing Guidelines:

  • Use circles for carbon stores/reservoirs.

  • Use arrows to represent flows/processes of carbon.

Measuring Carbon

• Importance of accurate measurements of carbon levels:

  • Direct Measurements:

  • CO₂ levels tracked since 1959.

  • Ocean acidification monitored through pH levels.

  • Photosynthesis rates directly measured.

  • Indirect Indicators:

  • Changes in global temperature.

  • Melting glaciers and rising sea levels.

  • Frequency and severity of extreme weather events.

  • Variation in rainfall distribution.

Atmospheric Monitoring

• Key Site: Mauna Loa, Hawaii - CO₂ levels measured since 1958 by Charles Keeling.

• Observations show a rising trend in atmospheric CO₂ over 50 years.

• Significant events influencing CO₂ levels are critical for understanding human impact on climate.