Sir: Trees are said to be the jugs of the earth so they have numerous advantages. The greatest among all is that trees are the sources of oxygen. All living things need oxygen to live. So trees take in carbon dioxide, the gas which we exhale, and give out oxygen. Unfortunately, trees are being cut to make buildings and homes and wood is being massively used for cooking food. It is estimated that in ancient times, half of the world was covered with forests and trees. No doubt, trees have a great effect on the temperature of the earth. If there are fewer trees then less carbon dioxide gas would be removed. I would like to mention that this problem can be overcome if the government takes some stringent measures. The concerned authorities need to launch awareness campaigns about the importance of trees among the general public. SABIR BALOCH Turbat