The Problem of Human Population

It has been reported that a thousand years ago there were less than 4000 million on earth . However now it is estimated that about more than 6,000 million people in the world . What is worse, it keeps growing at a fantastic speed . Firstly , global birthrate is growing faster and faster. In addition , progress in science which include chemistry, physics and biology , modern medicine decrease deathrate , for example , modern medicine has contributed to let babies grow up healthily and let people live longer . Furthermore, Technology made it possible for people to improve their lives . It also brought great changes in living conditions , particularly in the countryside , couples have many children and people tend to have large families . As a result , world's population increase rapidly. We call these condition of global population "population explosion".

There are some problems come following population explosion. Such as the shortages of food , water pollution , housing shortage and unemployment . A large population requires a great deal of food supply and shelter space. However , the limited productivity and scarce natural resources can hardly meet the needs of the over-increasing population. Besides that, people need jobs to earn money for expense , then they can maintain the subsistence. However jods are limited, but more and more people need jobs. In short, population explosion causes resources problems.

Mankind now confront with the danger of food shortages because the land where man can grow grains are reduced but people are increased . Although now it is hard to we imaging that people died since hungry, but it still exist in some parts of Africa. One of the important reasons is the great number of people with limited food. Population explosion can destroy the balance between population and food . On the other hand , some species have been died out already and many species are endangered . Because more and more wild animals are hunted for food as a supplement for the lacking grains, or since they are thought to present a threat to man .

However, researches indicated that one of the primary causes of the disappearance of wildlife is pollution ,which is one of the consequence of population growth and economic and especially in water pollution . We are using up our natural resources and at the same time polluting our environment with dangerous chemicals. With the development of modern agriculture and industry, more and more waste water is being poured into rivers. It has caused serious pollution. The river is becoming so dirty that no living things can not live in it.

Housing shortage is the other big problem resulted from population explosion, and it was prominent in China. The price of housing is higher in China today . In many chinese cities especially in the big cities , the speed of rising in price of housing is rapid