The Earth’s surface is about three-fourths water.
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As creatures of the Earth, so are we.
Water content of the body
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Only 2 or 3 percent of the world’s water is freshwater, not saltwater… and only 23 percent of the freshwater is liquid, not ice… and about half of that liquid freshwater is underground or otherwise inaccessible. So all plants and animals, including us humans, have to share about 0.35 percent of the Earth’s water to survive, which would be plenty if it were evenly distributed around the world… but it’s not.
Waters of the world.
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Half the world’s water supply is in nine countries—USA, Canada, Colombia, Brazil, Congo, Russia, India, China, and Indonesia—while more than a billion people don’t have access to clean water.
Note the word “clean.” That’s why water supply and sanitation (waste disposal) usually go hand in hand when discussing water. Unclean water has caused disease and famine throughout human history, especially during times of rapid population increase, such as the Middle Ages… and such as now.
Dirty water today kills 5,000 children a day.
(Reuters photo: Beawiharta)
Reuters photo: Beawiharta
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The world’s water supply today is more fouled than ever before, thanks largely to industrial waste…
Toxic sludge at a Hungarian chemical plant. (Inset photo by: AP/Bela Szandelszky)
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… and because of human population, which has exploded during the past 300 years.
Population growth during the past millennium.
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Long story short, humankind and life on Earth depend on clean, fresh water, whether it’s frozen at the poles and on mountain peaks, or flowing through rivers and lakes, or hidden underground, or evaporating into the atmosphere.
Looking to the future, there’s an ominous storm cloud moving our way… the result of:
- Exploding population and urbanization,
- Global warming and dwindling icepacks,
- Diversion for farming and industry,
- Uneven distribution,
- Polluted surface water from vast sources… agricultural nitrates, strip mines, pharmaceuticals, industrial chemicals, raw sewage…
- Destruction of wetlands,
- Toxic groundwater from fracking
I plan to explore some of those issues in the next installment.
Meanwhile, after reading dozens of water-related articles in the past couple of weeks, this was my favorite in terms of its clear presentation of all aspects of water in our lives. It’s several pages long, but worth the effort…
http://science.howstuffworks.com/environmental/earth/geophysics/h2o.htm
