Chapter 5 Summary and Analysis

Global population has exploded in the past 200 years. Shortly after the Industrial Revolution begins, the world population is only 900 million, less than India's population today. By 1930, the Earth's population has grown to two billion, and by 1975, it reaches four billion. At present rates, the Earth's population will reach eight billion by the year 2035. A combination of factors has caused this explosive growth. Death rates decline due to improved hygiene and medical advances. Two inventions, effective soap and the toilet, contribute significantly to the decline. Such advances have also helped babies survive, decreasing the infant mortality rates around the globe.

Infant mortality rates vary around the globe, however. In 2004, some countries, including Japan and Sweden, report all-time low infant mortality rates of 3 deaths per 1,000 births. Yet, at the same time, in 18 African countries and several Asian countries, infant mortality rates exceed 100 per...