history of earth's atmopshere

• 1. volcanic activity released water vapour
  2. water vapour condensed to form oceans
  3. carbon dioxide dissolved in oceans
  4. carbonates formed which produce sediments

  • reduced amount of carbon dioxide
• how oxygen increased:

  • algae and plants appeared and evolved
  • algae and plants absorbed carbon dioxide through photosynthesis
  • oxygen released through photosynthesis
• how carbon dioxide dexreased:

  • algae and plants absorb carbon dioixde through photosynthesis
  • marine animals evolved
  • shells contain carbonates
  • when they die, carbon locked up in rocks and fossil fuels
• • when plants, plankton and marine animals die, they fall to seabed and buried by sediment
  • compressed to form sedimentary rocks, oil and gas and trap carbon dioxide
  • crude oil formed from deposits of plankton
  • coal formed from plant deposits
  • limestone formed from calcium carbonate deposits of marine animals