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Population, Food, and Nutrition
Population Bulletin, Vol. 51, No. 4, February 1997
by William Bender and Margaret Smith
Introduction
Will the world be able to feed itself in the next century? Experts hold vastly different opinions on this question. Agricultural production has seen
extraordinary growth over the last few decades, which allowed per capita food supply to
increase despite unprecedented population growth. Human health and welfare have improved
enormously throughout much of the world. But there are warning signs that we may be
reaching the limits of agricultural expansion. Widespread problems such as erosion,
desertification, and salinization suggest that the amount of land available to produce
crops may be shrinking and that even current production patterns may not be sustainable.
At the same time, the unequal distribution of food within and among countries means that
840 million people worldwide, including 200 million children, do not have enough to eat.
Even more worrisome, the amount of food we demand is escalating as the world population
total climbs past 6 billion, and as people adopt more varied diets.
The balance between population size and food supply is the most basic challenge humans
face. At the end of the 18th century, Thomas Malthus argued that the Earth's capacity
to produce food was limited by the amount of arable land, and that this physical
limitation provided a natural check to total population size. He theorized that when
population exceeded the food supply, a surge of deaths from famines and illness would
eliminate the excess population, bringing the number of people back into balance with
available resources.
Since Malthus' time, the development of fertilizers, pesticides, and new strains
of wheat, rice, and maize, along with better farming techniques and machinery, have
expanded crop yields far beyond the wildest dreams of an 18th century farmer. World
population has grown six-fold. But the physical limitations to population growth that
Malthus hypothesized two centuries ago have been the subject of spirited debate ever
since. The debate has been strongly revived in the past several years.
In 1986, for example, Stanford biologist Peter Vitousek estimated that humans already use
nearly 40 percent of the Earth's terrestrial photosynthetic production. This suggests
that we might use nearly all the Earth's biological growth capacity by the middle of
the 21st century when the population is projected to be double its 1986 size. In 1990, the
Global Assessment of Soil Degradation (GLASOD), a project sponsored by the United Nations
Environment Programme, estimated that the productive capacity of nearly 2 billion hectares
of agricultural land has been seriously degraded, primarily through water and wind
erosion. This represents 17 percent of all land that grows vegetation. In 1994, the
Worldwatch Institute publicized a report stating that per capita grain production has
declined since 1984, and has since warned that food production is likely to fall short of
demand.
Although our capacity to grow enough food for the next generation is uncertain, we
produce sufficient food for the nearly 6 billion people alive today. Still, poverty,
natural disasters, political violence, and geopolitical factors prevent at least
one-seventh of the world from getting enough to eat. At the 1996 World Food Summit in
Rome, the international community reaffirmed the goal of ensuring that all people have
adequate nutrition for a normal, active life. Although the number and share of people
suffering from malnourishment has fallen over the past few decades, the task of ending
world hunger is formidable. It would take extraordinary political will to ensure food
security for the world's poor and disadvantaged. So far, national and international
support has been insufficient to accomplish the task.
In light of inevitable population increases, demographic changes, and environmental
pressures, concern about the future is justified. But we must go beyond projecting past or
current trends to obtain a picture of the eventual global food situation. This Population
Bulletin will provide an overview of the factors affecting global food supply and
demand and will highlight areas where changes in policy can either improve production or
reduce demand.
We will investigate how much food we have, how much food we need, and the sources of
potential increases in food demand. Most of the pressure for greater food supply will come
from growing numbers of people and changes in the demographic characteristics of the
population. However, economic development also increases demand for food. As incomes rise,
world trade and transportation networks expand and people around the world adopt more
varied diets.
We will also explore the intriguing opportunities for educational and policy
interventions that could both reduce the food wasted because of inefficient distribution
systems and lower food requirements. Such changes would help bring the food supply/demand
equation into balance, but are often ignored in traditional analyses of food resources.
We will examine the ability of the agricultural sector to meet future demands.
Environmental stress, slowing yield increases, and increasingly intensive agriculture are
signs that do not bode well for future food production. The issues are complex. Experts
disagree about the extent of environmental degradation and about the best ways to increase
agricultural productivity. The possibilities of alleviating demand for greater food
production through improved management of existing physical and technological resources
are also addressed.
The final section of this Bulletin examines the connection between the health
and sustainability of agriculture and the well-being of people. A large proportion of the
world's population derives its livelihood from agriculture. Food production is the
world's primary source of access to food, both through the generation of actual food
grown for consumption and the income gained through the sale of food crops.
The full text of this Population Bulletin is available in print only. Please visit our online store to order. Listed below are all the sections of this Bulletin.
Introduction
Food Supply and Malnutrition
How Much Food Do We Need?
Trends in Agricultural Production
Increasing Agricultural Production
Agriculture and Poverty
Government Policies
Strategies for the Future
Suggested Resources
References
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