How humans can affect the environment

How humans can affect the environment

1. Increase population

   • land
   • pollution and waste
   • energy
   • materials

2. Pollution

   • land
     • Physical
       • plastic
       • metal
     • Chemical
       • oil
       • gas
       • pesticides
   • Water
     • factory waste
     • oil
     • lakes
     • rivers
     • sea
     • sewage
     • eutrophication
     • Bioaccumulation
       • toxins build up through food chain and become more concentrated
   • Air
     • noxious gases
       • carbon dioxide, sulfur dioxide and nitrogen oxides
     • particulates
       • which are tiny particles suspended in air
         • breathing difficulties
         • global dimming
     • fossil fuels increases to provide more energy
     • increase in rice and cattle farming to supply more food generates methane
     • CO2
       • greenhouse effect
     • Sulphur and mnitric oxides
       • acid rain

3. Global warming

   • increase in greenhouse gasses increases to absorbtion of radiation therefore heating the earth
   • oceans rise due to melting sea ice
   • greater extreme weather
   • reduced biodiversity, all adapted to simular environment
   • organism distribution change
   • carbon dioxide
   • methane
   • nitrous oxide

4. Deforestation

   • Peat
     • Peat bogs absorb carbon dioxide. However, peat degrades and releases the stored carbon dioxide when it dries out, due to warmer temperatures, poor drainage and over-grazing
     • decayed vegetable, organic matter
     • Peat-free compost is encouraged to avoid extraction and degradation of peat. As it takes thousands of years to develop, the use of peat as compost is not sustainable
   • reduce in photosynthesis meaning less CO2 used

5. Biofuels

   • Ethanol
     • produced by the fermentation of sugar from plant material by yeast
       • maize
       • sugar cane
     • added to normal fuel to reduce emissions (Gasohol) 10% ethanol
     • yeast added to glucose and anaerobic respiration
       • ethanol and Carbon Dioxide
       • ethanol then distilled
   • Biogas
     • produced from the breakdown of organic material
     • anaerobic fermentation
       • by bacteria
     • methane
       • high level to be safe top burn, if only 10% it is highly explosive
       • 50-70%
     • carbon dioxide
     • hydrogen
     • round 30*C is best
       • hot countries is cheap
       • add energy then insulate
     • advantages
       • good for LIC's
         • low energy required
       • cheap
       • easy for hot countries
       • useful waste disposal
       • Landfill sites produce biogas from decay
         • removed as methane build up dangerous
       • can be used like normal gas
   • Advantage of biofuels
     • lower greenhouse gas emissions
     • less particulates
     • renewable // sustainable
     • conserve non renewable resources
     • often cheaper due to government insentives

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