The water on Earth today is all the water we will ever have.
The ocean holds most of it—over 97% of Earth's water is salty. Less than 3% is fresh—this is the water we drink, water plants with, and use to make things. Most of
the fresh water is locked up in glaciers and ice caps. Only a tiny bit of what's left over is available for humans.
Some places are too wet and others too dry. In fact, half of the world's fresh water can be found in only six countries! More than a billion people live without safe,
clean water, and the number of thirsty people is growing.