Derek McMonagle
Workbook
Contents Unit 1 Science and scientific processes 4 Unit 2 Nature of matter .................................................................................... 20 Unit 3 Cells and organisms................................................................................ 32 Unit 4 Energy ..................................................................................................... 54 Unit 5 Plant reproduction ................................................................................. 66 Unit 6 Sexual maturity, reproduction and personal hygiene...........................74 Unit 7 Sexually transmitted infections and drugs............................................ 82 Unit 8 Climate change....................................................................................... 90 3
8 Climate change (cont.)
8.3 The greenhouse effect
1 The following diagram represents the layer of greenhouse gases surrounding the Earth.
a) Complete the diagram by showing the effect of the layer of greenhouse gases on heat radiated by the Earth.
b) Briefly describe the effects of the layer of greenhouse gases.
c) The layer of greenhouse gases has existed for many millions of years. Explain why, as far as scientists are aware, it has only become a problem over the last 200 years.
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atmosphere Earth layer of greenhouse gases surface
energy from the Sun
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8.4 Greenhouse gases
1 a) Give the names of three gases, other than carbon dioxide, that make a significant contribution to the greenhouse effect.
b)
i) Draw a line on the grid to show how the concentration of carbon dioxide has changed from 1800 to the present day.
ii) Extend your line by adding a broken line to show how the concentration of atmospheric carbon dioxide will change between now and 2050 if nothing is done to reduce emissions of this gas.
2 The greenhouse index of CFCs is 23 000 while the index of carbon dioxide is 1.
a) What is the greenhouse index of a gas?
b) Explain why the contribution made by carbon dioxide to the greenhouse effect is far greater than that made by CFCs even though the greenhouse index of CFCs is much greater.
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year atmospheric carbon dioxide concentration (arbitrary units) 1800 1900 2000 2500
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8 Climate change (cont.)
8.5 Impact of climate change
1 The following graph shows how the average sea level at a location changed over the 20th century from a base line in 1900.
a) i) What trend is shown by the graph?
ii) Suggest why the graph is not a straight line.
b) Explain the trend shown by the graph.
c) The Maldives is a country in the Indian Ocean consisting of many small islands. The average height of the land is 120 cm above sea level.
Why is the population of the Maldives particularly worried by changes in the sea level?
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35 30 25 20 15 10 5 0 –5 1900 1920 1940 1960 year 1980 2000 change in sea level /c m
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8.6 Reducing climate change
1 a) What is a carbon dioxide sink?
b) Explain how each of the following acts as a natural carbon dioxide sink.
i) A forest
ii) An ocean
2 Explain how each of the following Government policies will reduce atmospheric carbon dioxide levels.
a) Making greater use of renewable energy sources.
b) Replacing petrol and diesel powered cars with electrically driven cars.
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