Water

Inefficient irrigation systems, the deforestation of water-storing forests, the over-exploitation of groundwater sources and the contamination of entire watercourses all lead to the depletion of water - a limited resource. The cultivation of maize, cotton and other plants which consume high levels of water in areas which are too arid for this type of crop also worsen water shortages. In many water scarce areas current per capita water consumption is unsustainable. Globally, water is sufficient to produce food for a grow­ing and wealthier population, but continuance with today's water management practices will lead to many acute water crises in many parts of the world (Global, p. 279). Approximately 40% of all food crops worldwide are grown on artificially-irrigated areas. Enormous investments in additional irrigation systems during the 1960s and 1980s, particularly in the densely populated regions of Southeast Asia, have substantially contributed to an increase in harvest. However, how and where such irrigation, along with river and groundwater usage, can possibly and appropriately be extended in the future, remains controversial (see also > agroecology).

Since the 1960s, the Aral Sea in Central Asia, located in what today is Kazakhstan and Uzbekistan, has been deprived of more water than is necessary to maintain its water levels. The fresh water that used to supply the sea is used by neighbouring countries to produce export crops, mainly cotton.
Large amounts of water from the two main rivers that feed the Aral Sea have been diverted to the desert so as to irrigate about 2.5 million hectares of land. In the 1960s, the Aral Sea received around 50 cubic kilometres of fresh water per year. By the early 1980s it received none.
By the 1990s, the surface area of the Aral Sea had shrunk by half and its volume had dropped by 75 percent. Its salinity had increased fourfold, preventing the survival of most of the sea's fish and wildlife. The desiccation of the Aral Sea has led to the loss of fisheries, contamination of water and soil, and the presence of dangerous levels of polluted airborne sediments (salt- and pesticide-laced particles). In addition, the regional groundwater table has fallen and many oases near the shore of the Aral Sea have been destroyed. By 1990, more than 95% of the marshes and wetlands in the region had given way to sand deserts.
The inhabitants of the adjacent communities face severe health problems. Drinking water is polluted. Chronic bronchitis, kidney and liver diseases have increased by 3000%. The infant mortality rate is one of the world’s highest (CWANA Report; p. 10).

There are nearly one billion people who do not have access to safe drinking water. Everyday, millions of women and children have to walk long, and often dangerous, distances in order to collect water and carry it home. As is the case for food and land, access to clean drinking water and water for agricultural usage is unequal. Water rights are often unfairly distributed, especially in Africa and Latin America. First, already more than a billion people live in river basins characterized by physical water scarcity. In these areas water availability is a major constraint to agriculture. (...) More areas will face seasonal or permanent shortages. Second, competition for water between sectors will intensify. (...) In most countries water for cities receives priority over water for agriculture by law or de facto, leaving less water for agriculture, particularly near large cities in water-short areas, such as MENA, Central Asia, India, Pakistan, Mexico, and northern China. Water for energy, i.e., hydropower and crop production for biofuels, will further add to the pressure on water resources. Third, signs of severe environmental degradation because of water scarcity, overabstraction and water pollution are apparent in a growing number of places with often severe consequences for the poor who depend heavily on ecosystems for their livelihoods (Global, p. 341). The IAASTD does not rule out that the water-scarce regions of Africa and Central Asia will have to import food products from regions with abundant water resources in the future. Today, this export of "virtual water" already takes place on a large scale, although in the opposite direction. Water embedded in cash crops is imported from developing countries, flowing mainly into the meat production systems of industrialised countries.