Water and land, shared out

Oceans and continents are not shared out equally between the Northern and Southern Hemispheres.

The book shows two maps drawn from straight above each pole and asks you to compare them. The answer: the Northern Hemisphere has more land than the Southern Hemisphere. So the Southern Hemisphere holds more water.

On those maps, the blue areas are the oceans together with their smaller parts, which have names of their own: sea, bay, gulf and so on. A sea or a bay is not something separate from an ocean; it is a part of one, with its own name.

Now the important catch. The oceans hold most of the water on the planet, but sea water is salty, and most land animals, including humans, cannot drink it. You could not fill a bucket from the sea and drink it at home.

Freshwater is only a very small share of the planet's water. It is found in glaciers, rivers, lakes, in the air, and underground (water under the ground is called groundwater).

So the book asks: if there is so much water on the planet, why do we hear so much about water scarcity or a water crisis? Because there is a great deal of water, but almost none of it is the kind we can drink. And even the freshwater is not all easy to reach: much of it is locked in glaciers or deep underground.

What ways of saving water do you know? Which ones have you seen at home, at school, and in your village, town or city?