human influences on the environment

• Greenhouse gases: Water Vapour, Carbon dioxide, Nitrous Oxide, Methane, CFS
• Humans have massively increased the level of CO2 in the atmosphere

  by burning fossil fuels in factories, power stations, houses and vehicles.
• Cattle on the planet produce methane as a waste product of digestion. Methane is released from the decay in landfill which is increasing.
• CFCs are manmade chemicals that used to be found in aerosols

  and fridges. They are mostly banned now due to them destroying

  the ozone layer which ends up letting more UV light in.
• Car fumes contains nitrous oxide. The use of fertilisers increases nitrous oxide because the nitrates are converted to nitrous oxide by denitrifying bacteria.
• Carbon monoxide is formed when petrol and diesel are burned in combustion engines. It binds to your haemoglobin instead of

  oxygen causing you to suffocate and die.
• Untreated sewage from humans, nitrates from fertilisers used by farms and pesticides have all caused damage.
• Water in streams and rivers become polluted with nitrates and phosphates from fertilisers that have leached from farmland into rivers and lakes. Sewage contains phosphates from detergents and nitrates

  from urine and faeces.
• Nutrients from sewage and fertiliser cause rapid growth of algae

  Other animals die – they cannot respire

  Bacteria use up oxygen in the water. It becomes anoxic

  Plants die because of lack of light

  Algal bloom blocks light

  Plants decayed by bacteria

  Oxygen levels fall
• Less evapotranspiration: less trees means less transpiration

  which can make the local climate drier.
• Leeching: As the exposed soil dries in the sun, rainwater

  runs off, rather than soaking in as before, and takes

  minerals with it leaving infertile soil.
• Soil Erosion: When it rains the soil gets washed away as

  there are no tree roots holding it in place anymore.
• More carbon dioxide and less oxygen: the trees that used

  to remove carbon dioxide and give out oxygen have been

  removed. More trees are burned for fuel releasing more

  CO2. This all contributes to more global warming.
• The sun releases short wave radiation

  When it strikes the earth some energy is readmitted as long wave radiation

  Some escapes into space but the rest is absorbed and trapped by the

  greenhouse gases in the Earth’s atmosphere

  This heats up the Earth
• Sulphur dioxide is released by burning fossil fuels.

  It dissolves in rainwater to make sulphuric acid which forms acid rain.

  This acidifies the water in lakes which kills many plants and animals sensitive to pH
• Acid rain kills trees. It damages leaves and releases toxic substances from the soil stopping minerals being absorbed.