Water, water everywhere, nor a drop to drink...

Who has not read that poem in school? But are schools and universities and politicians and scientists paying enough attention to something many of us take for granted?

Water is essential for existence (our bodies are full of it) but also for industry: according to theStockholm International Water Institute, and others concerned about the problem, each person on earth needs at least 1,000 cubic meters (m2) of water per year for everything from drinking, hygiene or growing food.

However, as usual the poor are those who suffer most from water shortages.Although we lack the precise figure, it is clear that most of the world's nearly 900 million souls who suffer from hunger also encounter serious difficulties in obtaining the water they need. While middle and upper income groups enjoy taking several baths a week, the world’s slum dwellers must often draw water from wells or other community sources and transport it to their homes.

Not a few experts foresee not only a growing energy crisis, but difficulties, conflicts and even wars over water or its distribution or availability. According to data collected by Peter Rogers in "Scientific American" an estimated one billion people, oneout of six, suffer inadequate access to safe freshwater. The United Nations predicts that by 2025 there willl be water stress in nearly half of the world’s countries.

Part of the problem has to do with the increased usage by middle and upper income groups--who are lucky enough to take a bath ever day or so, wash their cars, water their gardens and fill their swimming pools. Another aspect has to do with the climaticchanges produced by contamination--with zig-zag effects, from flooding to severe dry spells around the world.

Analysts such as those at BoozAllen Hamilton claim that a great increase in investment in water usage will be needed between now and 2030 to prevent a major world crisis. One figure mentioned: $1 trillion a year on applying erxisting technologies for conserving water, maintaining or replacing infrastructures, constructing sanitation systems.

Countries such as China and India will need to greatly increase their supply of water, in view of their rapid entrance into the consumer society. Decisions will have to be made concerning how much of the valuable water supply should be derived to the cities and how much used to produce food in the countryside.

Techniques for converting salt water to drinking water may help, and innovative conservation methods will also have to be developed. One example: the use of drip irrigation for plants, providing the exact amount for each plant.,