70% of Earth's surface is water of which 97.5% is salt water and 2.5% is freshwater. Less than 1% of this 2.5%
amount of freshwater is accessible (the majority is frozen in ice caps or exists as soil moisture). Below is a
further breakdown of freshwater use and availability.
- about 110,000 cubic km of precipitation fall on the world's continents
each year, most of which is absorbed by plants and/or evaporated back into the atmosphere
- 42,700 cubic km of this precipitation flow through river (the Amazon
carrier 16% of global runoff)
- 9,000 cubic km of freshwater are readily accessible for human use
- another 3,500 cubic km are captured and stored in dams and reserviors
We currently use about 50% of the world's readily available water.
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