Now there are many people suffering from water shortage in the world. What can we do to solve this problem? Some people think that the best way is to same water in each home.
Of course turning the tap off quickly often using water is a good way.
In fact, but wasting water in each home does not came water shortage in the world.
We need to think of the water for manufacturing the goods and agriculture if we really want to eliminate a water shortage.
For example it takes use of 2000 to 5000 liters of water to grow a kilogram of rice.
It takes 2000 liters to cook a bowl of sice topped with beef.
Average Japanese people use 250 liters in a day in their daily life but the water they consume in cooking take more than that.

Supporse a country which is dependent on imports for food produced the same amount of food domestically as it imports.
The water needed for that is called the water involved in the growing and manufacture of products traded around the world.