"Water is the greatest of all things," said the Greek poet Pindar. Many scientists presume that life itself began in water. There could certainly be no life without it; most living creatures consist mainly of water. But what if one day there were no water? Why should we care about the water of the future, and what can we do about it?

Flip through any science textbook and you'll read that water is renewable, that although it's used, it is never used up. But water usage is increasing. Although water covers three-fourths of the earth, 97 percent of it is salt water, and more than two percent is frozen in glaciers and icecaps. That means less than one percent of all water on this earth is usable, while water usage per person averages 100,000 gallons per year.

The world's six billion citizens are already appropriating 54 percent of all the accessible fresh water. United Nations' research shows that by 2025, we will use 70 percent - and this calculation reflects only the effect of population growth. If per capita consumption of water resources increases at its current rate, we would be using over 90 percent within 25 years, leaving only 10 percent for all other living creatures.

There is also another problem affecting the water system - pollution. Human and other animal wastes, toxic chemicals, metal and oils all pollute. To illustrate the problem, let us go to Milan, Italy. Doesn't that sound romantic? This famed city is where fashion designers come to seek fame. Is your mind filled with images of magnificent trendy shops? But, hey, hold your breath - Milan has the highest recorded level of sulfur dioxide pollution of any city in the world, which not only causes air pollution but also contributes to acid rain. Sulfur dioxide is a heavy, invisible and poisonous gas, and is the most widespread man-made pollutant. It's used as disinfectant, refrigerant, bleach, and food preservative. When absorbed by water vapor, it turns into acid rain and poses a serious threat to the environment as it increases the acidity of soils, lakes and rivers, endangering organisms. In Great Britain, an estimated 67 percent of forests have been damaged by acid rain.

Italy's longest river, the Po, now has pollution 10 times higher than officially recommended. It is estimated to discharge 250 tons of arsenic into the sea each year. And it's not alone - according to a 1992 water resources survey, 40 percent of America's rivers and 45 percent of its lakes are impaired or in poor condition; the leading polluter was agricultural chemical runoff.

Many governments have limited the amounts and kinds of waste that can be dumped into water. In addition, nations, states, cities and various industries have spent billions to reduce pollution and construct water treatment plants. But pollution has not stopped. Many cities still release untreated sewage into rivers, lakes and coastal waters. Some factories still discharge largely uncontrolled pollutants into the water through their sewer outlets or factory drains because it would cost much more to manage the waste.

Every year, some 300-500 million tons of heavy metals, toxic sludge solvents and other chemical wastes fall out from industry. As a result, high levels of mercury have been found in fish far from industrial areas. This means that the main sources of the mercury appear to be emissions from coal-fired boilers, municipal incinerators and smelters.

Another damaging effect is when large quantities of water are used to cool industrial equipment. Heat produced by the equipment makes the water hot, and as it's released into rivers and lakes, the heating causes thermal pollution, which can kill fish and plants. Even industries based on organic raw material, such as the food sector, also emit pollutants into the usable water system. At the end of the day, all this points to the decrease in usable water for the world's living things.

This is what happens when water is contaminated:

Every day, 6,000 people - most of them children under five - die from diarrheal diseases. Water-borne diseases including cholera, typhoid, polio, hepatitis A and meningitis kill more than 5 million people every year.

Another 2.3 billion people suffer from diseases linked to dirty water.

About 60 percent of all infant mortality worldwide is linked to water-related diseases.

The earth is expected to support another 5 billion people by the year 2050. This means sewage facilities must be provided to 383,000 new customers every day. In the year 2000, the world's demand for fresh water was double what it was in the 1980s.

What's next? What can we do? I live in a country where most energy is produced by hydropower. Worldwide, there are about 45,000 large dams. They have inundated more than 400,000 square kilometers of mostly productive land. Fully 20 percent of the world's freshwater fish are now endangered or extinct. About 80 million people have been forced to relocate as a result of their homes being replaced by dams. Although hydropower is economically feasible and could reduce greenhouse gas emissions, we would face the loss of wildlife habitats and aquatic biodiversity. Mini hydropower plants, however, would have minimal impact on the environment and be much cheaper.

Better water management should be applied to reduce the demand for water. It will never run out if we are smart enough to use water wisely, but some regions have a shortage because the people have not managed their supply well. Some look for new sources after polluting their water, others have plenty of water but not enough storage tanks, treatment plants and distribution pipes. More effective irrigation techniques, planting of drought and salt-tolerant crop varieties are also some ways out. And many industries can reuse water. Most steel companies in the west use a small amount of water over and over again in a circulating cooling system. Many communities in the United States have started to irrigate their crops with treated wastewater. As an alternative, we can also improve water-delivery systems.

United Nations Secretary-General Kofi Annan has said, "Unless we take swift and decisive action, by 2005, two-thirds of the world's population may be ... facing serious water shortages." Our generation has the responsibility of taking care of our planet. We all are children of the earth. It is useless if only the decision makers or a few of us are concerned about the water issue because this planet belongs to us all. We cannot accomplish anything big without support. To save the water of the future and to share this beautiful planet with future generations, are you, the master of the earth, prepared to fight this battle?