Human impacts: atmosphere Flashcards Preview

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Flashcards in Human impacts: atmosphere Deck (25)
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1
Q

Greenhouse gases

A

Carbon dioxide,

methane,

water vapour,

nitrous oxides

2
Q

Role of trees in the carbon cycle

A

Act as carbon sinks,

sequestering carbon dioxide from the atmosphere by photosynthesis

3
Q

The main source of CO2 emissions

A

Burning fossil fuels

4
Q

Describe the greenhouse effect

A
  • Light energy from the sun reaches the earth and is re-radiated as heat.
  • Greenhouse gases in the atmosphere trap the heat, preventing it from escaping into space.
  • This regulates the earth’s temperature, preventing it from becoming too cold at night.
5
Q

Explain the enhanced greenhouse effect

A
  • Deforestation means less CO2 is sequestered.
  • Industrialization means more CO2 is released.
  • CO2 levels in the atmosphere are increasing.
  • This leads to global warming
6
Q

Sum total of all of an individual’s CO2 emissions

A

Carbon footprint

7
Q

Ways to personally reduce CO2 emissions/carbon footprint

A
  • Decrease fuel consumption by walking, cycling, using public transport or using a car-pool.
  • Minimise air travel.
  • Use less electricity.
  • Insulate your home.
  • Use alternative energy.
  • Buy locally made goods.
  • Eat less meat and processed foods.
8
Q

Main sources of methane emissions

A
  • Decomposition in landfills
  • Sewage plants
  • Natural gas and crude oil industries
  • Rice plantations
  • Faeces of livestock
9
Q

Productive land is transformed into a desert

A

Desertification

10
Q

Causes of desertification

A
  • Climate change leads to less rain and warmer weather
  • Poor land management
11
Q

Examples of poor farming practices that lead to desertification.

A
  • Overgrazing or under grazing
  • over-cultivation
  • irrigation using poor quality groundwater
  • deforestation
12
Q

Effects of desertification

A
  • Loss of vegetation
  • Soil erosion
  • Loss of biodiversity
  • Soil releases more CO2
  • The decline in soil quality
  • Social unrest
13
Q

Ways to combat desertification

A
  • Prevent climate change
  • Improved farming techniques
  • Reduce deforestation
14
Q

Effects of global warming

A
  • Desertification
  • Increase in droughts and floods
  • Increase in extreme weather events
  • Melting polar ice caps and glaciers
  • A rise in sea surface temperatures
  • Loss of biodiversity
  • Spread of disease
  • Social unrest
15
Q

Deforestation

A

Permanent destruction of indigenous forest by felling and burning in order to clear land for other purposes

16
Q

Reasons for deforestation

A
  • Clearing land for urban development or agriculture
  • Use of wood for fuel or as a building material
  • Mining
  • Harvesting for traditional medicines
17
Q

Effects of deforestation

A
  • Increased global warming due to reduced carbon sequestration
  • Soil erosion
  • Reduced soil quality
  • Flooding
  • Loss of biodiversity
  • Disruptions to the water cycle
18
Q

Role of trees in the water cycle

A
  • Return water vapour to the air by transpiration - leads to cloud formation
  • Slow run-off and allow water to sink into the soil
19
Q

Ways to reduce deforestation

A
  • Recycle paper and cardboard
  • Legislation to protect forests
  • Plant trees
  • Select specific trees instead of clear-cutting
  • Create awareness
  • Promote sustainable practices
  • Mosaic forestry
20
Q

Mosaic forestry

A

Keeping areas of indigenous plants between trees planted for logging.

21
Q

Ozone

A
  • O3 gas in the atmosphere
  • Highly reactive
  • Absorbs UV radiation, preventing it from reaching the lower atmosphere.
22
Q

The main cause of global warming

A

Enhanced greenhouse effect caused by the build-up of greenhouse gases in the earth’s atmosphere. (NOT the hole in the ozone layer!).

23
Q

Ozone-depleting substances

A
  • Gases containing chlorine or bromine.
  • When released into the stratosphere they break down releasing Cl or Br, which cause degradation of ozone.
  • e.g. CFCs
24
Q

Responsible for higher levels of UV radiation, especially over the South Pole

A

Ozone depletion

25
Q

Ways to combat ozone depletion

A
  • Regulation and banning of ODS use
  • Alternatives to ODSs in industry
  • Create awareness
  • Use “ozone friendly” products