Human use of the environment

• Since the 1960s, there’s been a growth in large-scale, industrial farming where processes are increasingly done by machines

  • farming is becoming more mechanised
• industrial farming can increase the amount of food that can be produced, because processes such as milking, ploughing and harvesting can be done quicker
• changes in farming have impacts on the environment:

  1. field sizes have increased, removing hedgerows, leading to a decline in biodiversity
  2. uses of chemicals such as fertilisers and pesticides leached into water courses, killing wildlife
  3. heavy machinery causes soil erosion
• commercial fishing methods are used to catch and provide seafood as global demand for seafood is increasing. this has become more mechanised

  1. since the 1950s, boats have larger nets --> larger catches
  2. fish farms
• impacts of commercial fishing on environment

  • overfishing means some species are now endangered
  • fish farms are overcrowded —> waste —> released into natural environment —> algal bloom —> absorbs oxygen from water —> animals/plants die
• The overall demand for energy is increasing deforestation, as trees are burnt as fuel or cleared to make way for power stations

  • in some countries with a large river, hydroelectric power stations are set up to provide renewable energy
  • however the initial construction floods large areas of the forests
• environmental impacts of deforestation

  • releases co2 —> global warming
  • loss of habitat —> species die out
  • increased soil erosion —> washed into streams —> damaged fish habitats
  • increased flood risk
• another human use of the environment is mining, which we do to get fossil fuels, which are a major source of energy

  • surface mining: large areas of vexation stripped away so miners can mine
  • sub surface mining: digging deep shafts below the ground surface
• Environmental impacts of mining

  1. Waste polluted soil and groundwater —> toxic
  2. Habitats destroyed
  3. Coal/oil/gas are not sustainable —> global warming
• Seasonal variations in rainfall or unpredictable rainfall can cause a water shortage at certain times of year, and reservoirs can provide a reliable water supply
• Building a dam across a river traps a large amount of water all year.
• reservoirs and dams environmental impacts

  • reservoirs flood large amounts of land, destroying habitats and agricultural land
  • natural flow of sediment is disrupted, reducing the fertility of areas downstream
  • reservoirs create new aquatic environments, which can become home to non-native species
• water transfers use canals and pipes to move water from a river that has surplus water to a river that has a water shortage
• Water transfer environmental problems

  1. Large scale engineering works are needed to create new channels
  2. Energy needed to pump water over long distances —> GG gases
  3. Often build dams and reservoirs