Humans

• What can humans impact?

  the carbon cycle
• What has happened since the industrial revolution?

  The impact that humans have on the carbon cycle has increased hugely

  • we are causing carbon flows from lithosphere and biosphere to the atmosphere to happen faster than they normally would\
• 4 main human causes of change

  • hydrocarbon (fossil fuel) extraction and use
  • farming practices
  • deforestation
  • land use changes
• Hydrocarbon (fossil fuel) extraction and use:

  Extracting and combustion of fossil fuels releases Co2 into atmosphere

  • WITHOUT human intervention the carbon would remain sequestered in the lithosphere for thousands of years to come|
• Farming practices - what do agricultural activities do

  release carbon into the atmosphere
• How do farming practices release carbon into the atmosphere?

  • ANIMALS release CO2 and CH4 when they RESPIRE & DIGEST food
  • PLOUGHING releases CO2 stored in SOIL
  • GROWING RICE in RICE PADDIES releases LOTS OF CH4
• What has happened as the world's population has risen?

  food production has also risen

  = carbon emissions from farming increased
• What has also increased CO2 emissions (Farming)

  mechanisation of farming
• Deforestation-why are forests cleared?

  • agriculture
  • logging
  • to make way for developments\
• What is the effect of clearing forests

  Reduces the size of the carbon store, and, if cleared forest is burned, there's a rapid flow of carbon from BIOsphere--> atmosphere
• LAND USE CHANGES - what is a major source of carbon

  the change of land use from natural/agricultural --> urban
• land use changes - HOW are these sources of carbon

  • vegetation removed to make way for buildings= reduces carbon storage in the biosphere
• land use changes - HOW are these sources of carbon

  CONCRETE PRODUCTION releases lots of CO2 and lots of concrete is used when urban areas expand