Earth’s Precious Water


All of Earth’s water – every drop – salt & fresh

That large blue sphere over America represents all of Earth’s water. Its diameter is about 1370km (more than the distance from Pretoria to Cape Town) and has a volume of about 1,386,000,000 cubic kilometers). This sphere includes all of the water in the oceans, ice caps, lakes, rivers, groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant.

The sphere may look small, but its height is three times higher than the International Space Station, which flies about 400km overhead. If you pricked that bubble it would fill all the oceans & seas, (average depth 3.7km), lakes, rivers, ice caps, underground water, everywhere. If you spilled it just over the continental USA it would be 170km deep, seventeen times deeper than the deepest ocean trench.

Liquid fresh water

The second, smaller blue sphere over Kentucky represents the world’s liquid fresh water (groundwater, lakes, swamp water, and rivers). The volume comes to about 10,633,450 km3, of which 99 percent is groundwater, much of which is not accessible to humans. The diameter of this sphere is about 272 kilometers.

Water in lakes and rivers

Can you see the third tiny blue bubble over Atlanta, Georgia? That one represents accessible fresh water – the water in all the lakes and rivers on the planet. Most of the water people and life on earth need every day comes from these surface-water sources. Scary how small it is!! The volume of this sphere is about 93,113 km3. The diameter is about 56 kilometers. It is incredibly tiny compared to the globe, but if you’re thinking “can’t be that small” you have to try to imagine a bubble 56km high—say seven times higher than Mt Everest is above sea level (or fourteen times higher than Everest above base camp, the usual picture we see of the mountain).

Surface liquid fresh water is incredibly precious! Let’s not dam it, pollute it or waste it.


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