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If you gathered all the world’s water—from oceans, lakes, groundwater, water vapor, everything—into a sphere, it would have a diameter of about 1400 km. That’s the distance between say Southern Portugal and Paris. Such water is represented by the larger blue sphere in the figure. The much smaller blue sphere is the total drinking water available in the globe – and most of it is inaccessible to us: 74.5% of the drinking water is locked away in ice caps and glaciers and 24.7% is groundwater (much of that out of reach). There is only .56% of the world’s freshwater circulating in lakes, rivers, rainfall, soil and the biosphere, that is accessible to us. SAVE WATER!
Note: The illustration above (made by Jack Cook at the Woods Hole Oceanographic Institution) belies the real size and mass of such a sphere of pure liquid water. The total amount of water contained within would still be quite impressive — over 332.5 million cubic miles (1,386 cubic km)! (A single cubic mile of water equals 1.1 trillion gallons.) Still, people tend to be surprised at the size of such a hypothetical sphere compared with our planet as a whole, especially when they’ve become used to the description of Earth as a “watery world”.
