1.discuss on the impact of human population explosion on the environment and the world food problem as a biological and social issues.

Although world population growth is now beginning to slow as a result of social factors associated with the media, increasing education and role of women in society, the exploding population and its consequences in inevitable human impact on all aspects of the biosphere has been described as the most serious crisis ever to face the planet.

As the world population grows, so more efforts are made to bring in new productive areas to feed the unsustainable human populations that are burgeoning forth. By overstressing soils and ecosystems through application of artificial fertilizers, and pesticides, many of the best productive areas of the planet are slowly being reduced to marginal lands. Lack of long-term sustainable productivity will lead to continuing crises in food production.

The term population explosion refers to the situation that the human population grows so fast that it exceeds the carrying capacity of the environment.

It will bring us food and environment problems.

Firstly, we discuss the environmental one.

The living of human beings depends upon a large variety of natural resources including food, energy, water and land. They also depend on various materials for medicinal, recreational and many other purposes. 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 and faster rate. At the same time, utilization of natural resources results in production of waste products, which continuously pollute the environment. The impacts caused by the depletion of natural resources and the pollution problems are becoming more severe as the human population grows.

For example, deforestation, the clearance of forests and the conversion of them for non-forest uses, includes agriculture, animal grazing, timbering, and urbanization. As forests play a vital role in the biosphere. They act as a climatic buffer by retaining moisture in the air, cooling down the air, and maintaining the balance of carbon dioxide level in the atmosphere. They are also important as the habitats for a large variety of organisms. Clearance of forests will cause soil erosion, hotter and drier weather conditions, global warming, as well as reduction in biodiversity.

Then, we discuss the food problem.

Growing populations will have a serious impact on the need for food especially in the poor countries. While under normal weather conditions and assuming food production growth in line with recent trends, total world agricultural production could expand faster than population, there will nevertheless be serious problems in food distribution and financing, making shortages, even at today's poor nutrition levels, probable in many of the larger more populous LDC regions. Even today 10 to 20 million people die each year due, directly or indirectly, to malnutrition. Even more serious is the consequence of major crop failures which are likely to occur from time to time.

The most serious consequence for the short and middle term is the possibility of massive famines in certain parts of the world, especially the poorest regions. World needs for food rise by 2-1/2 percent or more per year (making a modest allowance for improved diets and nutrition) at a time when readily available fertilizer and well-watered land is already largely being utilized. Therefore, additions to food production must come mainly from higher yields. Countries with large population growth cannot afford constantly growing imports, but for them to raise food output steadily by 2 to 4 percent over the next generation or two is a formidable challenge. Capital and foreign exchange requirements for intensive agriculture are heavy, and are aggravated by energy cost increases and fertilizer scarcities and price rises. The institutional, technical, and economic problems of transforming traditional agriculture are also very difficult to overcome.

In addition, in some overpopulated regions, rapid population growth presses on a fragile environment in ways that threaten longer-term food production: through cultivation of marginal lands, overgrazing, desertification, deforestation, and soil erosion, with consequent destruction of land and pollution of water and impairment of inland and coastal fisheries.