Chapter 4
Water Resources as a limiting Condition on
World Population
Makoto Atoh
Deputy, Director-General
National Institute of Population and Social Security Research
Introduction
The increase in the world population in the 21st century will be a critical constraining condition on improvement of our living standards, and, together with economic development, will make substantial impact on the resources and the environment of the Earth. The increase in the world population itself is, in turn, constrained by the resources and the environment. As T. R. Malthus predicted in the end of 18th century, the increase in population must be "checked" either in a positive way or in a preventive way at some point. Despite the fact that fresh water is essential for human life today as potable water, one of the indispensable resources for food production, or industrial water, the issue of water (shortage) has not been seen as a great constraining condition of resources, except in some countries in desert zones. However, the world population towards the 21st century will be nearly doubled in the coming fifty years, which will necessitate the increase in irrigation water for more food production and the rise in the demand for water for daily-life use and industrial use due to industrialization and urbanization. Thus, water is very likely to become a scarce resource in many countries. This essay will review future prospects for the populations in major regions, and discuss the extents to which water resources can be a constraint on population growth in those major regions of the world.
1. World Population Prospects
(1) Estimates of Future Population by United Nations
The world population will reach 6 billion next year. Although the population growth rate has been declining since hitting its peak, 2.04% per annum, in the period between 1965 and 1970, it is still as high as 1.37% per annum today (1995 - 2000).
