1
How and why have human population size and growth rate changed over time? How many people live on Earth today?
INFOGRAPHICS 4.1 AND 4.2
A graph that shows human population size over the course of human history:
is a line that has steadily increased at a constant rate.
produces an undulating curve that rises and falls repeatedly, with our current population similar in size to past peaks.
resembles a J-shaped curve—flat at first, with a rapid upward rise since about 1800.
is an S-shaped curve—flat at first, then increasing rapidly for a few hundred years and then leveling off in the past 50 years.
C
Approximately ___________ people live on Earth today.
7 billion
What factors led to the increase in population growth rate during and after the Industrial Revolution?
Harnessing energy to run machinery increased our agricultural output and led to improvements in sanitation and health care —all of these things decreased death rates.
2
What cultural and demographic factors influence population growth in a given country? How do they differ between more and less developed countries?
INFOGRAPHICS 4.3 AND 4.4
Reducing infant mortality generally:
increases the rate at which a population grows.
decreases the rate at which a population grows.
has little effect on the rate at which a population grows.
B
An age structure diagram can be used to:
measure potential population migration to cities.
see the historical growth of a population.
predict the future growth of a population.
measure the quality of life of a population.
C
True or False: A population with more older people than young people has a lot of population momentum.
FALSE
Identify several factors that contribute to the high growth rate in developing nations like Niger.
Poverty that contributes to a high infant mortality rate and reduces life expectancy. This high rate of infant deaths likely contributes to a high birth rate as families tend to have more children when the chance of child deaths is high. This high death rate is probably linked to poverty. (Niger has a very low per capita GNP.)
3
What is the demographic transition, and why is it important? What is the current trend for global population growth?
INFOGRAPHICS 4.5 AND 4.6
The term demographic transition refers to:
slower growth as the population size approaches carrying capacity.
the decline in death rates and then birth rates as a country becomes industrialized.
the requirement for a population to reach a specific size before it becomes stable.
migration from the overpopulated countryside to urban centers.
B
In recent years, the world population’s growth rate has declined, but it is still a positive number. This means human population size:
has stabilized (neither increasing nor decreasing).
has started to fall.
is still increasing but more slowly than before.
will peak soon and then fall slightly.
C
Why might a modern-day developing nation in an intermediate stage of the demographic transition (experiencing lower death rates) not complete the transition to lower birth rates?
Other factors may influence birth rates such as cultural preferences for large families or slow economic development.
4
What are some strategies for achieving zero population growth?
INFOGRAPHIC 4.7
All of the following are pronatalist pressures except:
A child is part of the family labor pool.
There is a high infant mortality rate.
Contraceptives are not available.
Women have many opportunities to participate in the workforce.
D
What generally happens to a population’s total fertility rate (TFR) when the education that women receive increases?
TFR increases
TFR decreases
TFR is not affected by educational opportunities for women
B
In terms of reducing population growth rates, how important is reducing desired family size?
Desired family size is highly correlated with actual family size so providing birth control will not help a country reduce its population growth rate if large families are seen as desirable.
5
What determines Earth’s carrying capacity for humans? Is Earth’s carrying capacity enough to support the current or future (projected) human population?
INFOGRAPHIC 4.8
Which statement illustrates human overconsumption?
Japan’s fertility rate of 1.4 is below replacement-level fertility.
Average per capita daily water usage in the United States is 575 liters, while the amount needed for a reasonable quality of life is 80 liters.
At 176 deaths per 1,000 live births, Angola has the highest infant mortality rate in the world.
Per capita use of fossil fuels is decreasing in Denmark as a result of the carbon tax.
B
How could it be possible that we are already living beyond the long-term carrying capacity of Earth?
The key term here is “long-term”. By taking resources faster than they are replenished, we reduce the ability of the Earth to support us in the future.
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