1970 was World Conservation (保护) Year. The UN wanted everyone to know that the world was in danger. They hoped something could be done.
Here is one example of the problem. At one time there were about 1,300 kinds of plants, trees and flowers in Holland, but now only about 866 are left. The others have been destroyed by modern people and their science. We are polluting earth, air, water and everything around us. We can't live without these things. If things go on like this, we shall destroy ourselves.
What will happen in the future? Perhaps it's more important to ask "What must we do?". More and more young people have known this. Many of them are helping to save our Earth. For example, they plant trees. In a small town in the United States, a large group of girls cleaned the banks of 11 kilometres of their river. Young people may hear about conversation through an album called "No One's Gonna Change Our World". It includes songs of Cliff Richard and other singers. The money from selling it will help to conserve tigers, elephants and pandas on Earth.