Without water, it is impossible to grow crops or to raise livestock. No water, no food - no food, no life.
Fortunately, there is plenty of water. When photographed from outer space, our beautiful blue planet looks as though it should be called Water, not Earth. Indeed, if the world's water evenly covered the surface of the planet, it would form a global ocean 1.5 miles deep. All of the earth's land surface could fit into the Pacific Ocean, with room to spare.
Of course. most the earth's water is in the seas, and seawater is salty. If a person drank only seawater, he or she would soon perish of thirst and dehydration while the body tried to flush out the excess salt. Seawater is not a good choice for agriculture or industry either - it kills most crops and quickly rusts most machinery. So, for the most part, humans can use seawater only if they remove the salt, and that is an expensive process.
A mere 3 percent of the world's water is fresh, not salty. Almost all of that fresh water, about 99 percent of it, is locked up in glaciers and ice caps or is deep underground. Only 1 percent is readily accessible to humankind.
One percent does not seem like much. Are we likely to run short of fresh water? Probably not. States the magazine People & the Planet: "Even this [1 percent], if evenly distributed around the world and rationally used, would be enough to sustain twice or three times the world's current population."
Basically, the total amount of water on earth neither increases nor decreases. Science World states: "The water you use today may have once quenched the thirst of a dinosaur. That's because all the water we have on Earth now is all we've ever had - or will ever have."
This is because the water in and around the world endlessly circulates - from the oceans to the atmosphere, to the land, into the rivers, and back to the oceans again. It is as the wise man wrote long ago: "All streams run into the sea, yet the sea never overflows; back to the place from which the streams ran they return to run again." (Ecclesiastes 1:7 New English Bible)
Despite the abundance of fresh water on the earth, however, many regions are in crisis. The following articles look at the problems and the prospects for resolving them.
Mary, who lives in the United States, begins her day with a shower, brushes her teeth with the water running, flushes the toilet, and then washes her hands. Even before sitting down to breakfast, she may use enough water to fill the average bathtub. By the end of the day, Mary, like many others who live in the States, has used over 100 gallons of water, enough to fill a bathtub two and a half times. For her, a clean, plentiful water supple is no farther away than the nearest tap. It is always available; she takes it for granted.
For Dede, who lives in West Africa, it's another story. She gets up long before dawn, dresses, balances a large basin on her head, and walks five miles to the nearest river. There she bathes, fills the basin with water, and then returns home. For the next hour, she filters the water to remove parasites and then divides it into three containers - one for drinking, one for household use, and another for her evening bath. Any washing of clothes must be done at the river.
"Water hunger is killing us here," Dede says. "Having spent almost half the morning fetching water, how much of the day is left for farming or other activities."
Dede's situation is hardly unique. According to the World Health Organization (WHO), the total time spent each year by multitudes of women and children fetching and carrying water from distant, often polluted, sources amounts to over ten million years!
So while there is plenty of fresh water worldwide, it is not evenly distributed. That is the first major problem. Scientists reckon, for example, that while Asia has 36 percent of the water filling the world's lakes and rivers, that continent is home to 60 percent of the world's people. In contrast, the Amazon River contains 15 percent of the world's river water, but only 0.4 percent of the world's people live close enough to make use of it. Uneven distribution likewise applies to rainfall. Some regions of the earth are almost permanently dry; others, though not always dry, occasionally suffer from periods of drought.
A number of experts believe that humans may cause some changes in climate involving rainfall. Deforestation, overcultivation, and overgrazing all strip the soil bare. Some reason that when that happens, the earth's surfact reflects more sunlight back into the atmosphere. The result: The atmosphere becomes warmer, clouds disperse, and rainfall decreases.
Barren land may also cause a decrease in rainfall, for a great deal of the rain that falls on forests is water that first evaporate from the vegetation itself - from the leaves of the trees and undergrowth. In other words, vegetation acts like a huge sponge that absorbs and holds rainfall. Remove the trees and undergrowth, and less water is available to form rain clouds.
Just how dramatically human actions affect rainfall is still a matter of debate; more researth remains to be done. But this much is certain: Water shortages are widespread. Already, shortages threaten the economies and health of 80 countries, warns the World Bank. And already, 40 percent of the earth's inhabitants - more than two billion people - have no access to clean water or sanitation.
When faced with water shortages, rich nations usually manage to buy their way out of serious trouble. They build dams, employ expensive technology to recycle their water, or even remove salt from seawater. Poor nations do not have such options. Often they must choose either to ration clean water, which might curb progress and reduce food production, or to reuse untreated water, which results in the spread of disease. As demands for water increase everywhere, the future looks very, very dry.
Since 1990, overall progress in improving the lot of those without water and sanitation has been, according to WHO, "poor." Sandra Postel, when vice president of research at the Worldwatch Institute, wrote: "It remains a grave moral shortcoming that 1.2 billion people cannot drink water without risk of disease or death. The reason is not so much a scarcity of water or inadequate technologies as lack of social and political commitment to meeting the basic needs of the poor. It would take an estimated $36 billion more per year, equal to roughly 4 per cent of the world's military expenditures, to bring to all of humanity what most of us now take for granted - clean drinking water and a sanitary means of waste disposal."
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