The rate of population growth
Today, according to the United Nations estimates, the world population is around [?] billion people, a dramatic rise since [?], when Earth contained about [?] billion people.
Each day, the world human population increases by about [?] people. It doubles in [?] to [?] years.
Population growth is not due simply to an increase in births but to the excess of births over deaths. Improvements in public health and medicine enable people to live longer. As a result, the world population expands.
But the growth rate varies from country to country. In the richer, industrialized nations, population growth (with an average rate of [?]) is much slower than in the developing nations. The highest growth rates (about [?]) are in Africa (Ivory Coast, Kenya, Tanzania, Zambia, and Uganda) and in Arab states (Saudi Arabia, and Oman) on the Persian Gulf.
Poverty and population growth
Many economists believe that economic development is the key to slowing population growth. The difference between the rates of population growth in rich nations and the rates in developing nations seems to support this view.
In developing nations, where many people farm for a living, there is an economic advantage to having several children who can help with the work and provide for the parents in old age. In developed countries, modern agricultural techniques enable the production of the same amount of food using the labour of fewer people. In such societies, large families are unnecessary and family size drops.
Unfortunately, a rapidly expanding population can prevent a developing nation from improving its economy. Kenya, for instance, with a [?] population of [?] million will have [?] million in [?] if the current population growth rate continues. As a consequence, poverty may get worse unless the Kenyan government can limit its population growth.
China birth-control experiment
In [?], China began a programme that restricts families to having only one child. China is one of the most densely populated nations of the world. It has the largest population, estimated at more than [?] billion people.
By comparison, the United States, with [?] million people living on a land area approximately equivalent to that of China, has a population density of only [?] people per square mile.