Turn over
for Kerboodle & Revision
7
l Revised to more closely reflect the latest Edexcel B advice and
exam question wording
l The Student Book will be entered into the AQA approval process
59
58
Climate change
Section A - The challenge of natural hazards
Unit 1 - Living with the physical environment
Natural Hazards
What are natural hazards?
SKILLS FOCUS
On this spread you will use data and construct graphs to investigate shrinking
sea ice in the Arctic
Graphs and charts
Skills
● Completing and interpreting a line graph,
a divided bar chart and a pie chart
● Calculating mean, median and mode as
measurements of average
● Calculating percentages
1979-1989
1990s
2000s
2010-2018
1 Jan
1 Feb
1 Mar
1 Apr
1 May
1 Jun
1 Jul
1 Aug
1 Sep
1 Oct
1 Nov
1 Dec
30 Dec
2019
(series ends September 2020)
18
16
14
12
10
8
6
4
2
0Extent (millions of square kilometres)
A The seasonal patterns of Arctic sea ice extent (1979-2018)
Arctic sea ice extent (in millions of km2)
12
11
10
9
8
2000
1800
1600
1400
1200
Year
1000
800
600
B The extent of Arctic sea ice over the last 1500 years
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5 1980 1985Minimum Arctic sea ice extent
(millions of square km)
1990 1995 2000
Year
2005 2010 2015 2020
C Minimum extent of Arctic sea ice (1979-2005)
Is the Arctic sea ice shrinking?
On September 15 2020 the Arctic sea ice cover
reached its annual summer minimum. The area of
the Arctic Ocean where sea ice concentration was
at least 15 per cent sea ice was 3.7 million km2 -
the second smallest ever recorded.
Just as the surface of a pond develops a layer of
ice during cold winters, the surface of the Arctic
Ocean also freezes, forming sea ice. Salty seawater
has a lower freezing point than fresh water,
but once it cools to −2°C it starts to freeze. As
temperatures fall in autumn the extent of the sea
ice increases, to reach a maximum in early March.
As air temperature increases, the ice melts to
reach its annual minimum in September (graph C).
Skills
1 Study graph A.
a Describe the seasonal trends in the extent of
Arctic sea ice.
b Explain why these seasonal trends occur.
c What is the evidence on graph A to suggest
that the Arctic sea ice is shrinking?
2 Study graph B.
a Use a ruler to find the point on the line graph
for 1950.
b Describe the trend in Arctic sea ice extent up
to 1950.
c Suggest why scientists are concerned about the
trend aft er 1950.
3 Study graph C.
a Describe the trend in minimum sea ice extent from 1979-1996.
b How does the trend change in the period 1996-2005?
4 Use the data in table D to construct a line graph
showing the trend in minimum Arctic sea ice for
2006 to 2020. This will complete graph C. Use a scale
similar to that shown in the graph.
a Use a pencil to plot each value with a cross. Join
the crosses to complete your line graph.
b Annotate your graph to describe its features.
c Use the values in table D to calculate the mean
minimum sea ice extent for the period 2006-2020.
How does this compare to the median value?
6 As table E shows, the main greenhouse gas is
carbon dioxide. Table F lists the main emitters of
global carbon dioxide by sector.
a Construct a pie chart to represent the data in
table F. To convert percentages into degrees,
multiply by 3.6.
b Label each sector or construct a colour key.
c Describe the pattern of global carbon dioxide
emitters as shown by your pie chart.
D Minimum Arctic sea ice extent (2006-2020)
Year Minimum Arctic sea ice extent
(millions km2)
2006 5.9
2007 4.3
2008 4.7
2009 5.3
2010 4.9
2011 4.6
2012 3.6
2013 5.2
2014 5.2
2015 4.6
2016 4.5
2017 4.8
2018 4.8
2019 4.4
2020 3.9
5 Scientists believe that Arctic sea ice provides
evidence of global warming. This has been caused
by increases in greenhouse gases emitted by human
activities, which enhance the greenhouse eff ect.
Table E lists the main greenhouse gas emissions.
a Calculate the total percentage of carbon dioxide
emissions.
b Calculate the contribution of burning fossil fuels
as a percentage of all carbon dioxide emissions.
c Represent the data in table E in a divided bar
chart. Construct a bar 2cm wide and 10cm high.
d Using a vertical scale of 1cm = 10 per cent,
complete your divided bar chart using diff erent
colours or shading to identify each greenhouse
gas. Consider how best to colour/shade the three
diff erent sources of carbon dioxide. Add labels or
use a key to identify each gas.
Gas Percentage
Carbon dioxide (burning fossil fuels) 57
Carbon dioxide (deforestation, decay of
vegetation)
17
Carbon dioxide (other) 3
Methane (livestock, paddy rice, organic
waste decay)
14
Nitrous oxide (vehicle exhausts, agriculture) 8
Fluorinated gases (fridges, aerosols) 1
TOTAL 100
E Global greenhouse gas emissions
Sector Percentage
Industry 32
Building operations 28
Transportation 23
Building materials and construction 11
Others 6
F Global carbon dioxide emissions by sector
Analysis
1 What is the evidence that the Arctic sea ice is
shrinking?
2 With reference to greenhouse gas emissions,
suggest how Arctic sea ice shrinking might be linked
to climate change.
Evaluation
1 Evaluate the use of minimum Arctic sea ice as an
indicator of climate change.
2 Evaluate the eff ectiveness of mean, median and
mode in assessing the average annual minimum
extent of Arctic sea ice 2006-2020 (table D).
4.6
Practice question
Comment on the eff ectiveness of divided bar and pie
charts in representing data. (4 marks)
202912_AQA GCSE Geog SB_Ch04.indd 58-59
202912_AQA GCSE Geog SB_Ch04.indd 58-59 05/11/21 11:07 PM
05/11/21 11:07 PM
Extension tasks and
practice questions
on every spread help
students succeed
Draft Student Book
Up-to-date case studies
provide real-world
examples that your
students can relate to
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hone students' ability
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questions with confidence