Agriculture Reference
In-Depth Information
11.7
DEALING WITH POPULATION CHANGES
It is obvious that Earth's population is increasing. The present structure of world popu-
lation has a large number of young men and women who will enter their child-bearing
years soon. They will probably follow their parent's social mores and produce more
than the two children needed to replace them. The most realistic projections of world
population predicts about 9 billion humans will be alive on the planet by 2050.
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How will this affect our food supply?
11.7.1 Increasing Numbers of People
We are faced with constantly increasing numbers of people on Earth such that we may
feel like one of the people in the crowd of Figure 11.5. There must be some point when
the Earth's population increase comes into equilibrium with deaths so that the overall
number of humans is relatively stable. The birth rate of 2.1 children per woman is cal-
culated as the number of children needed to replace both parents and non-child-bearing
adults in a society. Because of the present population distribution in many countries,
even a birth rate of 2.1 children per couple will guarantee significant population
increases in the near future.
A case in point is India. Figure 11.6 shows that a large part of the total
population is under 20 years of age. As this segment of the population reaches child-
bearing age, they will contribute to a large increase in the total population even if
they only bear 2.1 children per couple by the year 2020. A dramatic population
increase is already guaranteed for India. Although China is now the most populous
country, by 2050 India will be the most populous country.
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India will probably not
be able to “put on the brakes” to its birth rate and is already committed to a huge
population increase.
This increase in total population is expected to occur in many other countries,
even if they achieve the replacement birth rate of 2.1 children. An example is
China. In 1950 the fertility rate was 6.2 children. After drastic measures limiting
Figure
11.5.
Threat of overpopulation.
