How life on earth caused environmental change

• Atmospheric oxygen :

  By 2.7 billion years Ago, some of the archaea in the oceans had developed the ability to photosynthesise and release oxygen.

  For millions of years, all the oxygen produced reacted with iron in the oceans and over time once all the iron had reacted with the oxygen, the surplus dissolved oxygen built up in the oceans.

  Oxygen in the atmosphere absorbed ultraviolet light.
• Carbon sequestration :

  Photosynthetic organisms, absorbed carbon dioxide some of which was stored in geological sediments such as carbonate rocks and fossil fuels.

  This reduction in atmospheric carbon dioxide levels helped prevent a long term temperature rise.
• Biogeochemical cycle :

  Photosynthetic organisms, absorbed carbon dioxide, some of which was stored in geological sediments such as carbonate rocks and fossil fuels. This reduction in atmospheric carbon dioxide levels helped to prevent a longterm temperature rise
• Transpiration :

  Once plants had evolved and colonised the land, transpiration returned water vapor to the atmosphere and increased the amount of rainfall to other areas. Making the growth of even more plant life possible.