human causes

• Anthropocene 


  recent period in earths history when human activity has significant impact on the planet's climate and ecosystem
• anthropogenic 


  environmental change caused or influenced by people directly or indirectly
• fossil fuels 


  • hydrocarbons lock up carbon in the lithosphere
  • hydrocarbons are extracted to produce energy and heat instead of remaining sequestered in the lithosphere
  • combustion and extraction releases co2 into the atmosphere
• farming


  • burning fossil fuels to run machinery for ploughing, harvesting
  • fertilisers
  • burning straw and stubble
  • livestock respiration and digestive processes release co2 and methane
  • bacteria in waterlogged soil produces methane
  • 70% of deforestation is due to agriculture
  • responsible for 1/3 of all human caused greenhouse gas emissions
• urbanisation 


  • deforestation, parks replaced with housing and concrete spaces
  • 2% of earth is urban but responsible for 97% of anthropogenic co2 emissions
  • emissions from transport, industry and land development
  • cement and concrete are used as building materials and the production releases co2
  • vegetation removed so photosynthesis can't happen
  • cites account for 80% of of energy consumption worldwide
  • 50% of population live in cites which will be 70% by 2050
• deforestation 


  • 20% of global co2 emissions
  • burning of wood for cleaning woodland releases co2
  • conversion of woodland for grazing reduces the ability to absorb co2
  • when forests are cleared and burned 30-60% of carbon is lost.to the atmosphere
• cement production


  • releases greenhouse gases due to limestone heating and fossil fuels used to create the heat
  • calcination - heats calcium carbonate breaking it down to calcium oxide and co2 (50% of all cement production emissions)
  • indirect emissions by burning fossil fuels to heat the kill - 40% of cement emissions
  • electricity is used for transportation and power plant emission - 5-10% of cement emissions