Carbon Cycle Processes

Biological Carbon Cycle

• Photosynthesis:
  • Process by which plants, algae, and some bacteria convert CO2 into organic compounds (glucose) using sunlight energy
  • Releases O2 as a byproduct
  • Occurs in chloroplasts of plant cells
• Respiration:
  • Process by which cells generate energy from glucose, releasing CO2 and H2O as byproducts
  • Occurs in mitochondria of cells

Geological Carbon Cycle

• Fossil Fuel Combustion:
  • Burning of fossil fuels (coal, oil, gas) releases stored carbon into the atmosphere
  • Human activity: major contributor to increased atmospheric CO2 levels
• Decomposition:
  • Breakdown of organic matter by microorganisms, releasing CO2 into the atmosphere
  • Occurs in soil, sediments, and oceans

Ocean Absorption

• Ocean Carbon Sink:
  • Oceans absorb CO2 from the atmosphere, forming carbonic acid
  • Calcium carbonate (CaCO3) formation reduces ocean acidity

Human Impact on the Carbon Cycle

• Increased CO2 Emissions:
  • Fossil fuel combustion, land use changes (deforestation), industrial processes
  • Enhances natural greenhouse effect, contributing to climate change
• Carbon Sequestration:
  • Efforts to mitigate climate change by capturing and storing CO2 emissions

Forms of Carbon in Carbon Sinks

• Organic Carbon:
  • Found in living organisms, soil, and sediments
  • Includes biomass, dead organic matter, and fossil fuels
• Inorganic Carbon:
  • Found in oceans, atmosphere, and minerals
  • Includes CO2, bicarbonate, and carbonate ions
• Carbonates:
  • Formed through weathering of rocks, ocean absorption
  • Includes calcium carbonate, limestone, and dolomite

Biological Carbon Cycle

• Plants, algae, and some bacteria convert CO2 into glucose using sunlight energy through photosynthesis
• Photosynthesis releases O2 as a byproduct and occurs in chloroplasts of plant cells
• Cells generate energy from glucose, releasing CO2 and H2O as byproducts through respiration
• Respiration occurs in mitochondria of cells

Geological Carbon Cycle

• Burning fossil fuels releases stored carbon into the atmosphere, contributing to increased atmospheric CO2 levels
• Human activity is a major contributor to increased atmospheric CO2 levels through fossil fuel combustion
• Microorganisms break down organic matter, releasing CO2 into the atmosphere through decomposition
• Decomposition occurs in soil, sediments, and oceans

Ocean Absorption

• Oceans absorb CO2 from the atmosphere, forming carbonic acid
• Formation of calcium carbonate reduces ocean acidity

Human Impact on the Carbon Cycle

• Human activities such as fossil fuel combustion, land use changes, and industrial processes increase CO2 emissions
• Increased CO2 emissions enhance the natural greenhouse effect, contributing to climate change
• Carbon sequestration efforts aim to mitigate climate change by capturing and storing CO2 emissions

Forms of Carbon in Carbon Sinks

• Organic carbon is found in living organisms, soil, and sediments and includes biomass, dead organic matter, and fossil fuels
• Inorganic carbon is found in oceans, atmosphere, and minerals and includes CO2, bicarbonate, and carbonate ions
• Carbonates are formed through weathering of rocks and ocean absorption and include calcium carbonate, limestone, and dolomite

Carbon Cycle

Biological Carbon Cycle

• Involves the movement of carbon between the atmosphere, oceans, land, and living organisms
• Carbon is exchanged through processes such as photosynthesis, respiration, and decomposition

Photosynthesis

• Converts sunlight, CO2, and H2O into glucose and O2
• Net equation: 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2
• Fixes carbon into organic compounds, such as glucose, used by organisms to fuel growth and development

Respiration

• Breaks down glucose and other organic compounds to release energy
• Net equation: C6H12O6 (glucose) + 6O2 → 6CO2 + 6H2O + energy
• Releases carbon back into the atmosphere as CO2

Decomposition

• Breaks down dead organic matter, releasing carbon back into the atmosphere as CO2
• Occurs in soil, water, and the atmosphere

Ocean Absorption

• Oceans absorb CO2 from the atmosphere, reacting with water to form carbonic acid and bicarbonate
• Oceans act as a significant carbon sink, absorbing approximately 25% of CO2 released into the atmosphere each year

Fossil Fuel Combustion

• Burns fossil fuels, releasing CO2 into the atmosphere
• Significant source of human-induced CO2 emissions

Geological Carbon Cycle

• Involves the movement of carbon between the Earth's crust, mantle, and atmosphere over millions of years
• Carbon is stored in rocks, such as limestone and dolomite, and is released through geological processes, such as volcanic activity and weathering

Human Impact on the Carbon Cycle

• Human activities, such as deforestation, land-use changes, and fossil fuel combustion, have significantly increased atmospheric CO2
• Human-induced CO2 emissions are a major contributor to climate change

Forms of Carbon in Carbon Sinks

• Carbon is stored in various forms, including:
  • Organic matter (e.g., plants, soil, and animals)
  • Inorganic carbon compounds (e.g., carbonates, bicarbonates, and CO2)
  • Fossil fuels (e.g., coal, oil, and natural gas)
  • Carbonate minerals (e.g., limestone and dolomite)
  • Dissolved inorganic carbon (e.g., in oceans and freshwater)

Explore the biological and geological processes of the carbon cycle, including photosynthesis, respiration, and fossil fuel combustion. Learn how these processes affect the environment and the flow of carbon.