Water is an abundant resource on Earth, but the amount of drinkable water is only a fraction of the world’s total water supply. It is estimated that only about 3 percent of the world’s water is actually drinkable. This is because about 96 percent of water is found in the oceans and must be processed before it can be used for drinking. In addition, a portion of the world’s drinkable water is in the form of ice at the polar caps, making the water basically inaccessible and leaving less than 0.4 percent of the Earth's drinkable water available for people to use.
More facts about water:
- The human brain is 75 percent water — the same percentage found in most types of living trees.
- Humans can go only about a week without water before dying. This assumes that the individual is in top physical condition. By contrast, humans can manage to go without food for about 30 days before passing away.
- Water expands when it freezes. Generally, the water will expand by about 9 percent as it freezes. Frozen water is less dense than water and many other liquids, which is why ice cubes float in drinks.
