Bio essay 1 Chan Yuk Ying 6S (22)

Discuss on the Impact of human population explosion on the environment and the world food problem as a biological and social issues.

The growth of human population does not conform to the normal sigmoid-shaped pattern of population growth. Human population had been small and steady for two million years before 1 AD. It increased slowly afterwards. Starting from the 19^th century, it was found to speed up dramatically. The increase is in an exponential way. Around 1800, the human population was 1 billion. It took about 130 years to double it and reach 2 billion. It then took only 45 years to double it again and reach 4 billion. The population is now over 6 billion in 2000.

It is believed that if the growth of human population is allowed to continue without restriction, the population density might exceed the carrying capacity of the Earth. Natural resources, such as food, water and land will become exhausted. As a result, a large number of people would die or suffer until the population density is reduced to a certain level.

The term ‘ population explosion’ refers to the situation that the human population grows so fast that it exceeds the carrying capacity of the environment such that human lives are threatened. It is evident that some areas on the Earth are already so over-populated that a single disturbance, such as a flood, drought or crop failure, will result in the deaths of thousands or even millions of people.

One of the major problems of population explosion is food supply. Food is known as a major limiting factor for organisms. The overall production of food in the world should still be enough to feed the present population. There is a surplus of food in developed countries while starvation and famine occur in some developing countries. It is estimated that one-third of the world’s population is consuming over one-half of the world’ food supply.

The reason of unbalanced food supply is the farmers want to earn more money in the export market. Most of them in the developing countries grow cash crops such as coffee, tea, cotton and tobacco. Therefore, less land is available for growing food crops. Also, in some countries, the pastures are over-grazes i.e. people allow too many cattle and sheep to feed on the pastures. The vegetation is eaten away at a rate mush faster than it grows. Consequently, the fertile topsoil is stripped off, resulting in the transformation of pastures into deserts.

Large quantities of food are being wasted in developed countries due to the wasteful eating habits of the people. Modification of the environment by human activities has resulted in increased chances of having natural disasters such as droughts, and floods in many part of the world. This would lead to the slow-down of food production. The frequent warfare also disturbs the production of food.

Human population explosion also causes environmental impact. As the population continues to grow, there is an increasing rate of consumption of resources in the environment. Thus, the natural resources that support human population are being exhausted at a faster rate. At the same time. Utilization of natural resources results in production of waste products, which continuously pollute the environment. The impact caused by the depletion of natural resources and the pollution problems are becoming more severe as the human population grows.

The problems will be more serious if the rate of population continues to grow so quickly. So it is time for us to do something to solve the problem and reduce the impact by controlling the birth rate and increasing the food production from crops.