The Earth contains 525 million km3 of water, distributed as follows: 2% is frozen and 97% is located in the oceans.
80% of the continental water is found on the surface, while the remaining 20% is underground or in the atmosphere.
Of all the water available on Earth, only 2.5% is fresh. Of that amount, 0.5% is found in underground reservoirs and 0.01% in rivers and lakes. Of the freshwater, 90% is found in Antarctica.
Despite these quantities, the amount of drinking water is decreasing alarmingly year after year due to pollution.