We call this a water planet. And, indeed, if its surface were completely level, the peaks, plateaus, and valleys all smoothed out like a billiard ball, the ocean would cover everything in several meters of water, and all the world's creatures would be sea life.

But in fact the globe has interesting irregularities, some of which became continents. Over the eons a few living things gave up their watery realms, took their chances on relatively dry earth, and ultimately got so used to it that now we call this orb "terra" instead of "aqua."

After several hundred million years, most land species can no longer tolerate the salinity of the sea. Yet we remain water creatures. Whether tomatoes, bacteria, cattle, snakes, potatoes, apricots, or people, if completely dehydrated we are but husks, at first glance hardly recognizable as what we were. We exist because we found ways to carry our water with us outside the deep. But like leaking sacks of liquid, the shapes sustained by their own wetness, we must continuously have our thirst assuaged. Even more than food, we depend on plentiful supplies of fresh water.

Yet this precious staple is in a short and dwindling supply. Less than 3% of the planet's water is fresh. The vast majority of that, around 90%, is frozen in Antarctic or Greenland ice sheets or, to a lesser degree, in sea ice, permafrost, snow cover, or glaciers.

But the planet's ice is melting, with much of the runoff going straight into the sea. What evaporates returns, of course, as rain, but most of the planet's precipitation occurs over the oceans.

Less than one half of one percent of the world's water flows in lakes, rivers, streams, and reservoirs.

An ever increasing amount of it is polluted by the agricultural or industrial activities or the natural wastes of humans or their animals, not to mention swimming pools, irrigated golf courses, etc. About two million tons of waste a day are dumped into streams and other fresh water sources. The recycling of polluted into renewed potable water is not occurring fast enough to keep pace with this loss in supply.

As our species' population increases, the ever more limited amount of fresh water must be used to meet an ever larger demand. Between 1970 and 1990, for instance, per capita water supplies decreased by one-third.

Moreover, with increasing world temperatures, many areas that have depended on essential annual rainfall will have less reliable weather patterns.

With so much water still abundant in one form or another, we need not, of course, die of thirst, though in some developing countries just this fate may become more common. Even now, over two billion people, more than a third of the population, lack readily available fresh, clean, sanitary water. Will expensive use of ice bergs, desalination plants, water mined from formations deep in the earth, and improved water conservation be likely to help such thirsty masses in our near future?

But in developed countries, with the means and funds to pay for a diminishing supply, an abundance of clean, safe to drink water will likely continue to be available, for a steeply rising price, though it may not be easy to take water so for granted as we have tended to till now.

It might become common in the next couple or three decades for bottled water to be sold not simply as a luxury preference of health-conscious "Yuppies" but as a necessity of daily life in a more costly 21^st Century.

For the individual or family, rain water collection systems may then become more worthwhile. But as industry, cities, and agriculture must pay more for their water, taxes and the prices of goods and services will inevitably rise for everyone.

In such a world, might there be a wealth-creating premium placed on still easily available water supplies? Might Greenland, Canada, or Southeast Asian nations become as rich by selling fresh, clean water as countries in the Middle East have from the sale of oil?

Might water futures be traded on the Chicago commodity exchange and strategic wars be fought to help assure a plentiful supply of this precious substance?

Whether through political compromise, free enterprise, or international cooperation, there are rational solutions to our worsening water problems. Let's hope that the looming difficulties over water are more happily resolved than with some of the economic and other issue differences countries and cultures through the centuries have had to face over the control and use of land.

Sources:

A Short History of Nearly Everything, by Bill Bryson.

Water Scarcity Could Affect Billions: Is This the Biggest Crisis of All? Michael McCarthy in Independent/UK; March 5, 2003.