Environment Flashcards
(27 cards)
Why are we taking more resources from the environment more quickly?
People around the world are demanding a higher standard of living. So we use more raw materials, but we also use more energy for the manufacturing processes.
How does our waste affect water?
Sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival. The chemicals used on land can be washed into water. Sewage and fertilisers can cause eutrophication.
How does our waste affect land?
We use toxic chemicals for farming - these can also get washed from land into water. We also bury nuclear waste underground and we dump a lot of household waste in landfill sites.
How does our waste affect the air?
Smoke and gases released into the atmosphere pollute the air
What are the 4 main human activities that reduce land and resources available to other and plants?
- Building
- Farming
- Dumping waste
- Quarrying for metal ores
When does eutrophication occur?
If too much fertiliser is applied and it rains afterwards, nitrates are easily leached into rivers and lakes
Describe what happens in eutrophication
- mineral ions from fertilisers or sewage enter the water
- the increased concentration of these ions cause algae/plants to grow faster
- eventually the water is so full of algae and plants that some organisms can’t get enough light to photosynthesise. So they start to die
- with more food available, microorganisms that feed on dead organisms increase in number
- the respiration of the microorganisms depletes all the oxygen in the water
- aerobic organisms die because of the reduced oxygen concentration
Give two reasons for deforestation
To provide timber to be used as building material
To clear more land for farming
What are the four main problems that deforestation leads to?
More methane in the atmosphere
More carbon dioxide in the atmosphere
Less carbon dioxide taken in
Less biodiversity
Describe how deforestation leads to more methane in the atmosphere
- rice is grown in warm, waterlogged conditions - ideal for decomposers. These organisms produce methane
- cattle produce methane and rearing cattle means that more methane is released
Describe how deforestation leads to more carbon dioxide in the atmosphere
- carbon dioxide is released when trees are burnt to clear land
- microorganisms feeding on bits of dead wood release carbon dioxide from respiration
Describe how deforestation leads to less carbon dioxide taken in?
Cutting down of loads of trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced
What are bogs?
Areas of land that are acidic and waterlogged
Why don’t plants that live in bogs fully decompose?
Because there’s not enough oxygen
What is peat formed from?
Partly-rotted plants
How does destroying peat bogs add more CO2 to the atmosphere?
- carbon is stored in the plays instead of being released into the atmosphere
- peat starts to compose when the bogs are drained, so carbon dioxide is released
- if we continue to destroy peat bogs, more carbon dioxide will be released, adding to the greenhouse effect
Why are peat bogs drained?
- so that the area can be used as farmland
- the peat is cut up and dried to use as fuel
- peat is sold to gardeners as compost
How can people do their bit to help the peat situation?
by buying peat free compost
Name 3 places where CO2 can be stored?
- oceans, lakes and ponds
- Green plants, where it is stored as carbon compounds
- peat bogs
How is the temperature of the earth controlled?
It is a balance between the heat it gets from the sun and the heat it radiates back
How do gases in the atmosphere act?
They naturally act like an insulating layer. They absorb most of the heat that would normally be radiated into space, and re-radiate it in all directions.
What are the main two ‘greenhouse gases’?
Carbon dioxide and methane
Why are we particuluarly worried about these two gases?
because their levels are rising quite sharply
What is global warming?
the earth is gradually heating up because of the increasing levels of greenhouse gases
