536 MHR • Unit 5 Population Dynamics
10.The data in the following table are United
Nations Population Division statistics for 1995
and 2000, as well as projections (calculated in
2001 and based on a scenario of reaching an
average worldwide fertility rate of 2.1 in 2050)
for a number of subsequent years. Construct an
age pyramid for each of the years. (Males and
females are not separated in these data, so you
will not have separate pyramids for the sexes.)
(a)What do you notice about the proportion of
individuals in the oldest age class? When
members of your cohort are in this age class,
what percentage of the population will
consist of individuals of about your age?
(b)What effect do you think the change in
proportion of older individuals will have
on the growth rate of the population? What
about on the ability of working people to
provide for the well-being of retired people
and of those who are too young to work?11.In 1999, Canada was one of the top 10 emitters
of carbon from fossil fuels in the world,
producing very high levels compared with
other countries (as shown in the table below).
Why do you think this is so? Do research to
discover what aspects of the Canadian lifestyle
contribute to our high level of carbon
emission. What steps can and should be
taken to reduce these emissions?12.Try to find out the quantity of waste deposited
annually by your city, town, or region in its
landfill, and find the quantity for one or two
similar populations of your choice. Calculate
the per capita amount of waste deposited in
each landfill for each area. Does it differ? What
factors might explain the difference? Suggest
ways to reduce the amount of material sent to
the landfill each year.CountryTotal emissions
(millions of tonnes)Per capita
emissions (tonnes)
United States
United Kingdom
Canada
India
Australia
Mexico
France
Germany
Japan1520
152
151
243
94
101
109
230
307
5.6
2.6
4.9
0.2
5.0
1.0
1.8
2.8
2.4
Per capita emissions for selected countries
(from the World Resources Institute)Human population for Earth
(United Nations Population Division)Population by age group (millions)
Year Total 0 – 14
1995
2000
2025
2050
2075
2100
2125
21505666
6055
7824
8909
9319
9459
9573
9746
1768
1800
1836
1747
1724
1713
1707
1706
15 – 59 60+ 80+
3354
3650
4807
5193
5166
5092
5078
5075
544
605
1180
1970
2428
2654
2788
2964
62
70
149
370
572
717
824
956
3.What is meant by the term “tragedy of the
commons”? Give an example of this problem
in Ontario.
4.Describe the range of environmental problems
associated with the use of cars.
5.How do pollutants adversely affect living
things? Give examples.
6.Irrigation can increase crop yields dramatically.
What problems can it cause?7.Do humans have a positive as well as a
negative impact on their carrying capacity?
Explain your answer.
8.In what places in Canada is smog likely to
be the biggest problem? At what time of year
is it worst?
9.Why do you think amphibians would be more
affected by ozone depletion than organisms
like reptiles? Amphibians have also been
seriously affected by acid precipitation. Based
on their biology, why do you think this might
be the case?INQUIRY