Water Scarcity: Real and Virtual Implications
Water Scarcity: Real and Virtual Implications

World Water Day 2007, held on March 22nd 2007, was marked by rallies in India, press conferences and marches in Zimbabwe, seminars in Bangladesh, support walks in Columbia, exhibitions in Bangkok, and other events around the world. Yet only months later, searches for water-related news stories in major newspapers yield little results, while the problems associated with access to water have not disappeared. The UN estimates that one billion people in the world still lack sufficient access to clean drinking water.

Despite the fact that 70 percent of the earth’s surface is covered by water, only one percent is fresh water that is available in easily accessible lakes and rivers. Most of the world’s fresh water sources lie beneath Antarctic glaciers and approximately one-quarter of the world’s supply is located in Lake Baikal in Siberia, Russia.1

While many consider water to be renewable resource, there is only finite amount available at any given period of time. In a constant cycle, water flows through land into the oceans, evaporates to form clouds, and then returns to land as rainfall. This water must supply the daily drinking, agriculture, manufacturing, and other needs for the world population, which has exploded from 1.6 billion people at the beginning of the 20th century to 6.5 billion people at present.

Water Inequality

In aggregate, there is an adequate amount of water to support the world population. Nevertheless, there is a significant range in per capita resource distribution. Canada contains 90,000 cubic meters of water per person. In contrast, the Middle East represents the most water-scarce region in the world. Yemen averages less than 200 cubic meters per person, and its population is expected to double by 2025.2 In Asia, most of the region receives 90 percent of its rainfall in less than 100 hours per year because of the monsoon climate.3

Water availability and pollution represents a significant obstacle for countries such as China. Industrial and economic growth, particularly in Northern China, has led to the depletion of the Yangtze River. China is currently undertaking a $40–60 billion project to divert water from the Yangtze River’s glacial headwaters in Tibet to the northern provinces. The water transfer of 40 billion cubic meters of water per year will be equivalent to the annual water flow of China’s second longest river, the Yellow River.4

Increasing the Water Supply

In many water-scarce regions, technology and capacity in rainwater harvesting––the capture and collection of rainwater––is being developed and enhanced. Regions that are building their capacity for rainwater harvesting include Australia, India, and the southwestern United States.5

Improving irrigation efficiency is another method for the alleviation of water scarcity. Worldwide variations in water efficiency illustrate the potential for technology to play a role in reducing water stress. In California, one ton of water is required to produce 1.3 kg of wheat; in Pakistan, the same amount of water usage yields less than half the amount. France produces twice the amount of maize as China with the same amount of water. China produces twice the amount of rice as India with the same amount of water.6

Irrigation technology is focused on increasing the “crop per drop” ratio. Drip technology aims to deliver water directly to the root zone of crops. Drip technology, however, is at a developmental stage, and is used on only one percent of irrigated lands worldwide. Ninety percent of such land is located in wealthy countries.7

Another water technology development focuses on desalination to convert seawater into freshwater. High energy costs associated with the desalination process, however, have generally limited such application to areas in the Middle East and coastal cities. Israel has, through reverse osmosis technology, reduced costs of desalination to the level of conventional water utilities.

Virtual Water Trade

Agriculture is the most significant consumer of water, accounting for 70 percent of water usage in the world. Agriculture averages 80 percent of the water usage in developing countries, and represents as high as 95 percent of water used in some countries where agricultural export is the predominant economic activity.8 The UN estimates that two to three liters of water are required for personal drinking purposes, and 20–300 liters for domestic needs. A person’s daily diet, however, requires between 2,000 and 3,000 liters of water in agriculture and production.9

Despite the significant geographic inequalities, it is often difficult or impossible to transport or divert volumes of water to water-stressed regions. Nevertheless, “virtual water,” or water used in the agricultural process, moves between countries and regions as a result of the international food trade. Sixteen percent of water usage in the world is the result of goods produced for export instead of for domestic consumption.

A virtual water import strategy is visible with many water-stressed countries. Jordan, for example, is between 80 and 90 percent dependent on virtual water imports.10 Relative water efficiency is also a key factor determining the types of crops or livestock produced by a country.

The virtual water trade also motivates the study of western consumption patterns and the impact of globalization on water supplies around the world. As people become more affluent, higher meat consumption and industrial goods usage will lead to greater demands on existing global water supply. On average, 1,000 liters of water is required to grow one kilogram of wheat. Between five and ten times more water results in one kilogram of meat. As a result, one hamburger requires up to 11,000 liters of water to produce.

All told, a typical U.S. meat diet is consumes 5.4 cubic meters of water per day. In contrast, a vegetarian diet represents 2.6 cubic meters and a diet for minimal survival requires one cubic meter of water per day. If the entire world adopted the average Western diet, there would be a 75 percent instant increase in global water needs. Western consumption habits and the patterns of trade therefore have significant implications for water-stressed countries that export agricultural commodities.

Global warming resulting in rapid glacial melt also represents a considerable consequence for water supply. The rivers that flow from the glaciers of the Himalayas and Tibet in turn feed two billion people. In the Central Asia region, the Aral Sea has already shrunk to a quarter of its 1960 original size. Melting glaciers will continue to result in a significant decline of the region’s water supply.

The world population is expected to grow to 8.9 billion people by 2050.11 At the same time, globalization and international trade will likely heighten rather than alleviate situations of water stress. Both real conservation efforts and a focus on virtual trade considerations are required to manage the world’s water supply if it is to meet rising global demands for this life-sustaining resource.




1 “Beyond Scarcity: Power, Poverty, and the Global Water Crisis,” Human Development Report 2006, United Nations Development Programme, p. 135.
2 Ibid.
3 Ibid.
4 Human Development Report 2006, p. 149.
5 Lisa Shipek, “Coping with water scarcity,” The Christian Science Monitor, 5 April 2007.
6 Human Development Report 2006 p. 152.
7 Ibid.
8 “Coping with Water Scarcity,” UN WATER, 22 March 2007, p. 10.
9 “Coping with Water Scarcity” p. 9.
10 “Virtual Water Trade – Conscious Choices,” World Water Council, 2004, p. 7.

11 “Coping with Water Scarcity” p. 10.

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