Environmental Science 3(3+0)

Carbon cycle

• Carbon dioxide (CO2) in the air and dissolved in water is the primary source of the element carbon.
  
• Through the process of photosynthesis, the carbon is removed from the CO2 and incorporated with other chemical elements in complex organic molecules.
  
• The CO₂ eventually finds its way back into the atmosphere when the organics are broken down during respiration.
  
• The combustion of fossil fuels (oil and gasoline) for energy is a human activity that increases the concentration of CO₂ in the atmosphere.
  
• CO₂plays a role in absorbing radiated heat and in regulating global atmospheric temperatures.
  
• A rise in CO2 levels in the atmosphere will tend to cause the average temperature to increase.