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Water is a chemical substance (H20) composed of hydrogen and oxygen that is
considered essential for the survival of all known forms of life. Water
refers to the liquid form of the element but it can be solid as ice or
gaseous as in steam and water vapour. Water covers 71% of the earth’s
surface, found mostly in oceans, lakes and other bodies. The saltwater
oceans hold 97% of surface water, glaciers and polar ice caps around 2.4%
(now decreasing) and other land surface water such as rivers, lakes and
ponds 0.6%. Clean, fresh drinking water is essential to life; however some
experts estimate that by 2025 more than half of the global population will
face water shortages. As water plays a vital role in the world economy with
agriculture consuming around 70% of our freshwater, we should not take it
for granted but use it very efficiently. |
