Think Globally
Breaking Down the Water Supply
Water is a common chemical substance, essential to all known forms of life. About 1,460,000,000,000,000 (1,460 trillion) tons of water covers 71 percent of the Earth’s surface, but relatively little is suitable for consumption. In many parts of the world, suitable water is in very short supply.
Let’s scale the world’s water supply to a size easier to comprehend like 58 gallons, about the same as a really full bathtub.
- a full 55 gallon drum of that water is saltwater ocean.
- About 10 pounds of ice is locked in polar ice caps and glaciers.
- About one drop is in the atmosphere as vapor, clouds, and precipitation.
- Another drop is in our soil, and part of life itself (our bodies are made up mostly of water, for instance).
- Our drinking water sources:
- Almost one gallon of that water is below ground in aquifers.
- Three-fourths of this is polluted or otherwise unavailable to us.
- We are left with less than a liter of this water to live on.
- About four tablespoons of that is in surface water such as rivers and lakes.