Human Impact on the Environment

Revision Card on the Human Impact on the Environment.

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  • Created by: Chang Kim
  • Created on: 26-04-13 11:25

Human Impact on the Environment

The effects of the human population explosion:

  • Human population is rapidly frowing, and the standard of living is rising.
  • More waste is being produced. If not taken care of, it can pollute the water, air, and land.
  • We reduce the land available for animals/plants by building/quarrying/farming and dumping waste.

We pollute the land in several different ways:

  • Toxic chemicals such as pesticides and herbicides can pollute the land.
  • If sewage is not treated & handled properly, it can pollute the water.
  • Fertilisers and toxic chemicals can be washed from the land into the water and pollute it.
  • Sewage & fertilisers can cause eutrophication in waterways.
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Human Impact on the Environment

Eutrophication:

  • This is the process when fertilisers dissolve in rainwater, and get into ponds etc.
  • They then let the plants at the top grow quickly, killing away the plants under the water.
  • The light blockage also kills all the animals inside, meaning the pond is dead.

Air Pollution:

  • When people burn fossil fuels, CO2 is released into the atmosphere.
  • Sulfur dioxide & nitrogen oxides can be released when fossil fuels are burned. These gases dissolve in rainwater and make it more acidic.
  • Acid rain may damage trees directly. It can make lakes and rivers too acidic for plants and animals to live in them.
  • Air pollution can cause global dimming and smog as tiny solid particles in the air reflect away the sunlight.
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Human Impact on the Environment

Deforestation & Peat Destruction:

  • Deforestation is the destruction or removal of areas of forest or woodland. Deforestation leads to loss of biodiversity.
  • Land is used to: a) Grow staple foods eg. rice, or ingredients for cheap food in the developed world eg. palm oil from oil palms. b) Rear more cattle for the beefburger market. c) Crops that can be used for biofuel eg. sugarcane & maize.
  • Large-scale Deforestation has led to an increase in the amount of CO2 released into the atmosphere (from burning and the actions of micro-organisms). It has also reduced the rate at which CO2 is removed from the air by plants.
  • More rice fields and cattle have led to increased levels of methane in ithe atmosphere.
  • The destruction of peat bogs releases carbon dioxide into the atmosphere.
  • Trees, plants in peat bogs and algae in the sea all use carbon dioxide for photosynthesis. Carbon compounds are then 'locked up' in these plants.
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Human Impact on the Environment

Global Warming

  • Increasing levels of CO2 and methane in the atmosphere give rise to the greenhouse effect, leading to global warming- an increase in the temperature of the surface.
  • Global warming causes a number of changes: climate change, a rise in sea level, changes in migration patterns and distribution of species, and loss of biodiversity.
  • Climate Change: Severe/unpredictable weather: high winds/extensive flooding. 
  • Rising sea levels: North/South Pole + Glaciers will melt, raising sea levels, flooding more low-lying shores and maybe eeven countries.
  • Changes in migration patterns: Climates become colder/hotter + seasons change= migration patterns of birds/insects/mammals may change.
  • Changes in distribution: Animals may get increased/shrunked range as climate change makes conditions favourable. Some may disappear completey from a country.
  • Reduced biodiversity: As the climate changes,many organisms wont be able to survive and become extinct eg polars bears are at risk.
  • Global warming => less carbon dioxide is sequestered in oceans and lakes.
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