A Future of Scarcity

Years of rapid population growth and increasing per capita consumption have squeezed the world’s freshwater resources. As global population has grown to nearly 6.1 billion today (and continues to grow by about 78 million people each year), the demand for fresh water in some areas exceeds nature's capacity to provide it. A growing number of countries are expected to face water shortages in the near future—shortages that will be fueled by problems both on the demand side (notably rapid population growth) and on the supply side (mainly inadequate water supplies and poor policies).


Declining Water Availability Per Capita

There is no more water on earth now than there was 2,000 years ago, when the population was less than 3 percent of its current size. Fresh water's per capita availability, which has been falling for centuries, has been dropping more precipitously in recent years as the globe's population growth has exploded. Unsurprisingly, the availability of fresh water has also fallen, from 17,000 cubic meters per person in 1950 to 7,044 cubic meters in 2000 (World Resources, 2000). The supply of fresh water per capita is one third lower now than it was as recently as 1970, a direct result of the nearly 2 billion people added to the planet since.

While population growth rates are slowing in most developing countries, absolute numbers of people added each year remain near historic highs. As a result of projected population growth, global per capita availability of fresh water is likely to be no more than 5,100 cubic meters in the year 2025 (Gardner-Outlaw & Engelman, 1997).

China and India, the world's first and second most populous countries, respectively, provide examples of how even modest population growth rates can translate into large absolute numbers because of an already-enormous population base. China's population growth rate in 2000 was only 0.9 percent—but, with China's total population at over 1.2 billion, even this small growth rate translates into an additional 12 million people each year. Similarly, India's population growth rate of about 1.8 percent means that about 18 million people a year will be added to its current population of one billion. The world's annual population growth of 78 million a year (as of 2000) implies an increased demand for fresh water on the order of 64 billion cubic meters a year—an amount equivalent to the entire annual flow rate of the Rhine River, assuming countries continue to withdraw water at current rates (Clarke, 1991). And, as noted above, rapid population growth not only makes it increasingly difficult to provide adequate supplies of fresh water; it can also strain resources for proper sanitation, housing, health care, education, employment, and food supplies.