Population growth – Effect on food supplies and environment:
As the world population continues to grow in almost all continents, great pressure is being placed on arable land, water, energy, and biological resources to provide an adequate supply of food while maintaining the integrity of our ecosystem. As the world population grows, the food problem will become increasingly severe. The most venerable will be population in developing countries. The per capita availability of world grains, which make up 80 per cent of the world's food, has been declining for the past 25 years. Certainly with a quarter million people being added to the world population each day, the need for grains and all other food will reach unprecedented levels.
A. Below, world population and its growth trend is given.
* 10,000 years ago, 10 million people,
* By 1850, population was 1 billion,
* 80 more years to reach 2 billion (1930),
* 45 years, it doubled again (4 billion in 1975),
* 12 years to reach to reach 5 billion (1987),
* 6 billion in 1999,
* By the year 2020, there will be 8 billion?
There are ¼ million people added to the planet per day. This exponential growth is mostly happening in developing nations.
B. More than 99 per cent of the world's food supply comes from the land, while less than 1 per cent is from oceans and other aquatic habitats. The continued production of an adequate food supply is directly dependent on ample fertile land, fresh water, energy, plus the maintenance of biodiversity. As the human population grows, the requirements for these resources also grow. Even if these resources are never depleted, on a per capita basis they will decline significantly because they must be divided among more people.
At present, fertile agricultural land is being lost at an alarming rate. More than one-third of the world's cultivated land (1.5 billion hectares) has already been abandoned during the past 40 years because erosion has made it unproductive and this degradation of agricultural land is almost permanent. Most replacement of eroded agricultural land is now coming from marginal and forest land. Thus, pressure for agricultural land accounts for 60 to 80 percent of the world's deforestation. The shortage of productive fertile land combined with decreasing land productivity is the major cause of current food shortages and associated human malnutrition.
C. Water is another critical item for all crops. Massive amounts of water are required during the growing season for cultivation. In fact, agricultural production consumes more fresh water (about 87 per cent of the world's fresh water) than any other human activity. In many countries, people are facing shortage of fresh water. Competition for water resources among individuals, regions, and countries and associated human activities is already occurring with the current world population. Water resources, critical for irrigation, are under great stress as populous cities, states, and countries require and withdraw more water from rivers, lakes, and aquifers every year. A major threat to maintaining future water supplies is the continuing over-draft of surface and ground water resources.
D. Fossil energy is another prime resource used for food production. Nearly 80 per cent of the world's fossil energy used each year is used by the developed countries. The intensive farming technologies of developed countries use massive amounts of fossil energy for fertilizers, pesticides, irrigation, and for machines as a substitute for human labor. In developing countries, fossil energy has been used primarily for fertilizers and irrigation to help maintain yields rather than to reduce human labor inputs. Because fossil energy is a finite resource, its depletion accelerates as population needs for food and services escalate. Thus, cost of fuel increases everywhere.
E. Certainly improved technology will assist in more effective management and use of resources, but it cannot produce an unlimited flow of those vital natural resources that are the raw materials for sustained agricultural production. For instance, fertilizers enhance the fertility of eroded soils, but humans cannot make topsoil. Indeed, fertilizers made from finite fossil fuels are presently being used to compensate for eroded topsoil. A productive and sustainable agricultural system depends on maintaining the integrity of biodiversity. Strategies for the future must be based on the conservation and careful management of land, water, energy, and biological resources needed for food production.
F. Yet none of these measures will be sufficient to ensure adequate food supplies for future generations unless the growth in the human population is simultaneously curtailed. Several studies have confirmed that to maintain a relatively high standard of living throughout the world, the optimum world population should be less than 2 billion. Therefore, from now until an optimum population is achieved, strategies for the conservation of land, water, energy, and biological resources are to be implemented effectively. Maintaining a sound and productive environment allover its protection is essential.