Chapter 6, Problem 1CR

To determine

The way in which the human population has surpassed 7.4 billion. The three factors that have led to a rapid increase in human population over the past 200 years.

Answer to Problem 1CR

The population on the earth was 2 billion about 200,000 years ago. The exponential increase in population growth rate caused an increase in the world population to 7.4 billion. The three factors that are responsible for the increase in population are the development of agriculture, technology, and medicine. These factors have decreased the death rate and increased the overall population.

Explanation of Solution

About 200,000 years ago, the estimated population of a human being was 2 billion. After 50 years, the population of a human being on the Earth became double. In 1974, the population on the earth was around 4 billion, and in the next 25 years, the population increased to 7.4 billion.

The three most populated countries of the world include China (1.38 billion, India (0.33 billion) and the United State (324 billion) people. In case, the population keeps increasing by this rate, the population of the world would be 9 billion in 2050. According to scientists, the exponential growth of human population is unsustainable on the earth. The increasing population would utilize more natural resource which would lead to a deficiency of resource and life would become difficult.

Three factors that cause an increase in population on the Earth are explained as follows:

(i) Agriculture emerged about 10,000 years ago. The development of agriculture increased food production on earth. It increased the survival of the human population.

(ii) Development of technologies helped the human being to examine the weather conditions. There are various technologies which provide information about earthquakes and tsunamis. Human beings are capable of reducing the extent of damage caused by natural disasters. It also increases the survival of people and lowers the death rate.

(iii) The development of hospitals and medicines also decreased the death rate. There are a lot of antibiotics and vaccines that can prevent infectious disease. It improves the health of people that increase the survival of people, and the death rate is decreased.