GCSE AQA Biology 3 Environmental Issues

Nota:

• Reduced no. of people dying from disease & hunger

1. Causing increased demand on environment - take more resources, people demanding higher standard of living, use more raw materials & energy for manufacturing

1. Water

   Nota:

   • Sewage & toxic chemicals from industry can pollute lakes, rivers & oceans, chemicals used on land can also be washed into water (fertilisers)
2. Land

   Nota:

   • Toxic chemicals are used for farming (pesticides & herbicides), nuclear waste is buried underground & household waste is dumped in landfill sites
3. Air

   Nota:

   • Smoke & gases released into atmosphere can pollute the air - sulphur dioxide can cause acid rain

1. Building
2. Farming
3. Dumping waste
4. Quarrying for metal ores

1. Many processes cause it to be released
   1. Too much carbon dioxide causes global warming
      1. Carbon dioxide can be sequestered in natural stores like oceans, lakes & ponds, green plants & peat bogs

1. If didn't happen, at night there'd be nothing to keep heat in
   1. The greenhouse gases keep heat in - main ones are carbon dioxide & methane
      1. Earth is gradually heating up because of increasing level of GG - global warming (type of climate change that causes other types of climate change)

1. Done for various reasons...
   1. To provide timber for building material
   2. To clear more land for farming - to provide more food/grow crops for biofuels
   3. To produce paper from wood

1. MORE METHANE - rice is grown in warm, waterlogged conditions (ideal for decomposers which produce methane); cattle produce methane as well
2. MORE CARBON DIOXIDE - released when trees are burnt to clear land; microorganisms feeding on dead wood release carbon dioxide from respiration
3. LESS CARBON DIOXIDE TAKEN IN - cutting down lots of trees means less is removed during photosynthesis
4. LESS BIODIVERSITY - (biodiversity = variety of different species in habitat) habitats like rainforests contain huge numbers of species so when they're destroyed some may become extinct causing number of lost opportunities

1. Carbon in plants stored in peat instead of being released - if peat bogs are drained (so area can be used as farmland/cut up & dried for using as fuel/being sold as compost) then peat starts to decompose, releasing carbon dioxide
   1. People should buy peat-free compost to reduce demand for peat

1. Sea gets warmer & expands causing sea level to rise
2. Higher temp. makes ice melt causing sea level to rise more
3. Changing weather patterns - regions will suffer more extreme weather e.g. more hurricanes
4. Distribution of species may change - some may become more widely distributed (ones that need warmer temp.) & some may become less (ones that need colder temp.)
5. Biodiversity could be reduced if species can't survive a change in climate & become extinct
6. There could be a change in migration patterns