The Evolution of the Atmosphere

• 5) Photosynthesis causes oxgyen levels to rise and algae and bacteria fill the sea.
• Currently Nitrogen is the most abundant gas in the atmophere.

  
• 2) The Earth became cooler, and water vapour condensed forming oceans.

  
• In the current atmosphere: 80% Nitrogen Gas, 20% Oxygen, <1% Carbon Dioxide, Water Vapour and the Noble Gases

  
• 1)In the early atmosphere, Scientists believed Intense Volcanic activicty/eruptions released mainly Carbon Dioxide.