In this world human beings depend much on trees. Trees supply us with oxygen, food, furniture, etc. In every breath we take oxygen in and leave carbon dioxide out. Trees leave oxygen out and take carbon dioxide in. But at present people are cutting down trees at a large scale. Every day our population is increasing. So, more firewood and furniture are needed for the additional people. It takes thousands of years to grow a tropical rain forest. But at present they are being cleared at the rate of fourteen square miles per hour. For this, ‘Greenhouse Effect’ has occurred and the temperature of the world is increasing day by day. Ice is melting in the South and North Poles. The level of water in the sea is increasing and many countries will go under water. Measures should immediately be taken to prevent deforestation. We should plant five trees if we cut down one. We should also try our best to stop cutting down trees and save the environment.