Environmental Engineering Reference
In-Depth Information
Population Decline from a Rising
Death Rate: The AIDS Tragedy
A large number of deaths from AIDS disrupts a
country's social and economic structure by removing
large numbers of young adults from its age structure.
Between 2000 and 2050, AIDS is projected to cause the
premature deaths of 278 million people in 53 coun-
tries—including 38 countries in Africa. These prema-
ture deaths are almost equal to the entire current popu-
lation of the United States. Read this paragraph again,
and think hard about the enormity of this tragedy.
Unlike hunger and malnutrition, which kill mostly
infants and children, AIDS kills many young adults.
This change in the young-adult age structure of a coun-
try has a number of harmful effects.
First,
it produces a
sharp drop in average life expectancy. In 8 African
countries, where 16-39% of the adult population is in-
fected with HIV, life expectancy could drop to 34-40
years.
Second,
it leads to a loss of a country's most produc-
tive young adult workers and trained personnel such
as scientists, farmers, engineers, teachers, and govern-
ment, business, and health-care workers. As a result,
the number of productive adults available to support
the young and the elderly and to grow food and pro-
vide essential services declines sharply.
Analysts have called for the international commu-
nity—especially developed countries—to develop and
fund a massive program to help countries ravaged by
AIDS in Africa and elsewhere. This program would
have two major goals.
First,
it would reduce the
spread of HIV through a combination of improved ed-
ucation and health care.
Second,
it would provide fi-
nancial assistance for education and health care as
well as volunteer teachers and health-care and social
workers to help compensate for the missing young-
adult generation.
7-3 SOLUTIONS: INFLUENCING
POPULATION SIZE
Economics: The Demographic Transition
As counties become economically developed, their
birth and death rates tend to decline.
Demographers have closely examined the birth and
death rates of western European countries that became
industrialized during the 19th century. From these
data they have developed a hypothesis of population
change known as the
demographic transition:
As
countries become industrialized, first their death rates
and then their birth rates decline. This transition takes
place in four distinct stages (Figure 7-11).
Some economists believe that today's developing
countries will make the demographic transition over
the next few decades. Other population analysts fear
that the still-rapid population growth in many devel-
oping countries will outstrip economic growth and
overwhelm some local life-support systems. As a con-
sequence, many of these countries could become
caught in a
demographic trap
at stage 2, the transition
stage. This is now happening as death rates rise in a
number of developing countries, especially in Africa.
Indeed, countries in Africa being ravaged by the
HIV/AIDS epidemic are falling back to stage 1.
Analysts also point out that some of the conditions
that allowed developed countries to develop in the
past are not available to many of today's developing
Stage 1
Preindustrial
Stage 2
Transitional
Stage 3
Industrial
Stage 4
Postindustrial
High
80
70
60
50
Birth rate
40
30
Death rate
20
10
Total population
Low
0
Low
Increasing
Very high
Decreasing
Low
Zero
Negative
Growth rate over time
Active Figure 7-11
Generalized model of the
demographic transition.
There is uncertainty over whether this
model will apply to some of today's developing countries.
See an animation based on this figure and take a
short quiz on the concept.
