Zusammenfassung der Ressource
GCSE AQA Biology 3 Environmental Issues
- Human impact on
the environment
- Population is rising very
quickly - mostly due to modern
medicine & farming methods
Anmerkungen:
- Reduced no. of people dying from disease & hunger
- Causing increased demand on environment - take more
resources, people demanding higher standard of living,
use more raw materials & energy for manufacturing
- Producing more waste - it affects...
- Water
Anmerkungen:
- Sewage & toxic chemicals from industry can pollute lakes, rivers & oceans, chemicals used on
land can also be washed into water (fertilisers)
- Land
Anmerkungen:
- Toxic chemicals are used for farming (pesticides & herbicides), nuclear waste is buried underground & household waste is dumped in landfill sites
- Air
Anmerkungen:
- Smoke & gases released into atmosphere can pollute the air - sulphur dioxide can cause acid rain
- Humans reduce amount of land &
resources for plants & animals by:
- Building
- Farming
- Dumping waste
- Quarrying for metal ores
- Carbon dioxide & the greenhouse effect
- Carbon is present in
atmosphere as carbon dioxide
- Many processes cause
it to be released
- Too much carbon dioxide
causes global warming
- Carbon dioxide can be sequestered in natural stores
like oceans, lakes & ponds, green plants & peat bogs
- Gases in atmosphere naturally act as insulating
layer - absorb heat that would be radiated out
into space & re-radiate it in all directions
- If didn't happen, at night there'd
be nothing to keep heat in
- The greenhouse gases keep heat in - main ones are carbon dioxide & methane
- Earth is gradually heating up because of increasing
level of GG - global warming (type of climate
change that causes other types of climate change)
- Deforestation
- Definition: The cutting down of trees
- Done for various reasons...
- To provide timber
for building material
- To clear more land for farming - to
provide more food/grow crops for biofuels
- To produce
paper from wood
- Leads to 4 main problems...
- MORE METHANE - rice is grown in warm, waterlogged
conditions (ideal for decomposers which produce
methane); cattle produce methane as well
- MORE CARBON DIOXIDE -
released when trees are burnt
to clear land; microorganisms
feeding on dead wood release
carbon dioxide from respiration
- LESS CARBON DIOXIDE TAKEN IN -
cutting down lots of trees means less
is removed during photosynthesis
- 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
- Peat bogs
- Bogs are areas of land that are acidic & waterlogged -
plants living in bogs don't fully decay when they die
(not enough oxygen) so gradually build up to form peat
- 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
- People should buy peat-free compost to reduce demand for peat
- Climate change
- The consequences of global warming
- Sea gets warmer & expands causing sea level to rise
- Higher temp. makes ice melt
causing sea level to rise more
- Changing weather patterns - regions will suffer
more extreme weather e.g. more hurricanes
- 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.)
- Biodiversity could be reduced if species can't
survive a change in climate & become extinct
- There could be a change in migration patterns