March 22, 2013 - World Water Day

Whatncould be more crucial to the quality of life than plenty of cleannwater?
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nWenhumans use water to drink, to cook, to wash up and clean things, tonkeep our crops and livestock and gardens and pets alive, to makenproducts, to play, and even as a source of natural beauty. And innseveral of these uses, not just any water will do – it’s got to benfresh (not salty), unpolluted, drinkable water!

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n(Anothernword for water that is safe to drink is potable.)

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nAnyoung woman named Megha Kumarnwon a contest for this year’s Water Day slogan: “Water, waterneverywhere, only if we share.”

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Althoughnabout 70% of the Earth is covered by water, most of it is salty oceannwater. As a matter of fact, 96.5% of Earth’s water is in its oceans!nSome of the rest of Earth’s water is tied up in glaciers and icecaps,nsome is deep down in the ground, and some is vapor high in the sky. Antiny percent of Earth’s water is fresh water in rivers, lakes,nreservoirs, and aquifers. n

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nOfncourse, water isn’t just sitting still. Everyone knows about thenwater cycle: water evaporates from the ocean (and every other waternsource) and as vapor becomes part of the atmosphere; then the vaporncondenses back into liquid or freezes into ice crystals; eventuallynit falls out of the sky as rain or snow or sleet or hail. It eithernpacks up on the ground (as snow or ice), or it runs off of or seepsninto the ground (as water). Some of the rainwater and snowmelt findsnits way into rivers and lakes, and rivers eventually run into thenocean. Water, water everywhere—changing its state from liquid tonvapor to frozen and back again to liquid—changing itsnlocation—sometimes picking up pesticides and industrial ornsanitation waste, picking up minerals, eroding rocks, carrying soil.
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nAndnlet us not forget that part of the water cycle is involves livingnthings. Animals drink water, and plants soak up water with theirnroots; both animals and plants release water back into thenenvironment in several ways.

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Ournhuman bodies are from 60 to 70% water, and some creatures are aboutn90% water (by weight). Here on Earth—and scientists suspectneverywhere—life is dependent on water. Planetary scientists whonhope to find some sort of life on other planets aren’t just on thenlookout for water, they’re looking for liquid water. Thesenscientists point out that the biochemical reactions that sustain lifenneed fluid to occur, because molecules can dissolve into liquid, andnsubstances can move from one place to another in a cell or body.nGetting molecules where they need to go is too hard within a solid.nAnd gas-based (vapor-based) life would go all to pieces because in angas molecules move too much, too quickly.

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nOkay,nso fresh, clean, liquid water is super important to all of us. It isnunevenly distributed on Earth, and we can’t count on the same amountnthroughout the year. What to do? That winning slogan I told you aboutngives one hint: we should share. If we all conserve water whenever wencan and cooperate with each other to share water and to sharentechnology to purify water, we will all be better off.