(3) Water

UN Secretary-General message "International Year of Water Cooperation

Power-Water

Most of the freshwater we withdraw is used to irrigate crops

Worldwide, we use 70% of the water we withdraw each year from rivers, lakes, and aquifers to irrigate cropland. Industry uses another 20% of the water withdrawn each year, and cities and residences use the remaining 10%.

Affluent lifestyles require large amounts of water. For example, it takes 400,000 liters (106,000 gallons) of water to produce an automobile, up to 125,000 liters (33,100 gallons) to produce 1 kilogram (2.2 pounds) of grain-fed beef, and 9,000 liters (2,800 gallons) to produce 1 kilogram (2.2 pounds) of aluminum. You could save more water by reducing your annual consumption of grain-fed beef by 1 kilogram (2.2 pounds) than you would by denying yourself a daily shower for almost 2 years.

CASE STUDY

Freshwater Resources in the United States

The United States has more than enough renewable freshwater. But much of it is unevenly distributed or is contaminated by agricultural and industrial practices. The eastern states usually have ample precipitation, whereas many western and southwestern states have too little. In the East, most water is used for energy production, cooling, and manufacturing. In many parts of the eastern United States, the most serious water problems are flooding, occasional urban shortages, and pollution. In the arid and semiarid areas of the western half of the United States, irrigation accounts for 85% of water use. The major water problem is a shortage of runoff caused by low precipitation, high evaporation, and recurring prolonged drought.

Almost half the water used in the United States comes from groundwater sources with the rest coming from rivers, lakes, and reservoirs. Water tables in many water-short areas, especially in the arid and semiarid western half of the lower 48 states, are dropping quickly as farmers and rapidly growing urban areas deplete many aquifers faster than they can be recharged.

In 2003, the U.S. Department of the Interior mapped out water hot spots in 17 western states. In these areas, competition for scarce water to support growing urban areas, irrigation, recreation, and wildlife could trigger intense political and legal conflicts between states and between rural and urban areas during the next 20 years.

Water Shortages Will Grow

More than 30 countries-most of them in the Middle East (Core Case Study) and Africa-now face water scarcity. By 2050, some 60 countries, many of them in Asia, are likely to be suffering from water stress. Per capita water resources in China, the world’s most populous country, are less than a third of the global average, and falling.

THINKING ABOUT

Water and the Middle East

How might scarcity of water in the Middle East (Core Case Study) affect nations that are dependent on oil from the Middle East, and how could this impact your lifestyle?

 

Poor people bear the brunt of water shortages. In 2005, the United Nations reported that 1.1 billion people-one of every six-lack regular access to enough clean water for drinking, cooking, and washing, and 2.6 billion people do not have access to basic sanitation.

This already serious situation will almost certainly get worse as resource consumption and population continue to increase. According to the United Nations, between 2 billion and 7 billion people will face water shortages by 2050. The likely result: a flood of refugees from arid and semiarid regions searching for water, land, and food.

Water shortages and shifts in water distribution from global warming will also affect many people in developed nations. Because 70% of the world’s water is used to produce food, water shortages can translate into food shortages that lead to economic and social stresses.

In addition to global warming, several trends can worsen stresses on the world’s interconnected water and food supply systems. They include migration to cities whose populations divert river water from croplands; more rapid depletion of aquifers through the use of powerful diesel and electric pumps; and degradation and destruction of cropland from urban sprawl, soil erosion, desertification, and salinization.

Water hot spots in 17 U.S. western states that, by 2025, could face intense conflicts over scarce water needed for urban growth, irrigation, recreation, and wildlife.

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