Frozen water occurs in the earth's polar caps, from which it breaks off in the form of icebergs, and in more temperate latitudes in the form of glaciers in our high mountains.

The quantity of water 'immobilized' in this way is immense. At 43 million km3, there is about 3 times as much water there as in all the worlds aquifers, and 120 times as there is in all the world streams, rivers and lakes.

While there have been attempts to tow huge icebergs from Antartica to the Persian Gulf, these proved to be impractical, and too costly to be a viable alternative supply of fresh water, even for this very dry, and ultra rich, region.

Nobody has so far devised a technically and economically feasible way of permitting humanity to develop this vast quantity of fresh water.