Based on current trends, it is doubtful that we can feed a world population of10 billion. The recent World Health Organization report signals the seriousness of the human population explosion and food security problem, indicating more than 3 billion people now are malnourished worldwide. This is the largest number and proportion of malnourished people ever in history. Malnourishment is a serious disease, for it increases a person’s susceptibility to other diverse diseases, like malaria, diarrhea, and AIDS. Sick and diseased people find it difficult to work and even to enjoy their daily lives.
Per capita shortages of basic food resources are responsible for much of this malnutrition. Poverty, as well as inadequate or unfair distribution of food supplies, also contributes.
Cereals are the mainstays of human diets, comprising 80% to 90% of the world food supply. Although cereal grain harvests per hectare have increased slightly since 1984, these harvests have to be divided among ever more people, thereby decreasing the per capita availability of grains. Food availability per capita as measured by cereals has been declining since 1984.
Meanwhile, the world population is projected to increase from 6 billion to 10 billion in about 40 years, based on the current rate of growth. Even if a policy of 2.1 children per couple — instead of the current 2.9 children — were to be adopted tomorrow, the world population would continue its increase for approximately 70 years before stabilizing at nearly 12 billion. A vital factor affecting population growth is "population momentum." This momentum is directly related to the current young age distribution of the people in most countries, and is responsible for the continued population growth that would still occur with a potential change to 2.1 children per couple. Clearly, national populations with a median population age of only 16 years will continue to grow and increase for the full 70 years.
With more people on earth, more food, more water, more shelter, and more jobs will be required. As the human population expands, it spreads farther than ever before over the land with houses, roads, industries, and other activities. In this process, prime cropland, fresh water, and other vital resources for food production are compromised.
Consider that more than 99% of human food comes from the land, with less than 1% from oceans and other aquatic ecosystems. Food production requires fertile cropland, freshwater, and sunlight. Successful agriculture also requires both renewable and fossil energy for cultivation, fertilizers, pesticides, and irrigation.
Yet at a time when food production should be increasing dramatically to meet the needs of a rapidly expanding population, per capita world cropland declined 20% during the past decade. Each year, more than 10 million hectares of cropland are degraded and lost because of wind and water erosion. Erosion is intensifying worldwide, especially in developing countries where the rural poor remove crop residues for cooking fuel. Valuable forests are being removed for new cropland, while often poor farmers are cultivating marginal, unproductive lands.
In arid regions, farmers must use irrigation water. However, irrigated cropland per capita has declined about 10% during the past decade because of population growth and the salinization and waterlogging that destroy cropland. Sometimes farmers can not afford to irrigate.
Despite all projections about human population growth, no one really knows exactly how large the human population will be in 50 years. We know that the more than 6 billion people currently living on the planet are already stressing the earth’s land, water, and biological resources and polluting the environment. We know that 3 billion malnourished people are already too many.
To improve the growing imbalance between human population numbers and food supply, humans should actively conserve cropland, freshwater, energy, and other environmental resources. Populations in developed countries could contribute by reducing their high consumption of resources. The development of appropriate, safe agricultural technologies holds promise of improving food production.
As the human population increases, personal freedoms from malnourishment, hunger, poverty, and diseases are gradually eroded. Freedom to enjoy open space and treasured natural environments are diminished.
If we are not brave enough to limit our numbers, nature will impose its own limits on our numbers and existence.
