Planet Earth is 4600 million years old. It is difficult for us to think about such an enormous length of time, but if we simplify it into an understandable idea, we can compare the planet Earth to a person of forty-six years of age. Nothing is known about the first seven years of this person’s life; and very little information exists about the middle period; we know that it was only at the age of forty-two that Earth began to flower. Dinosaurs and great reptiles did not appear until one year ago, when the planet was forty five. In the middle of last week men-like apes became ape-like men. Modern Man has been around for four hours. The Industrial Revolution began just a minute ago. During those sixty seconds of biological time, Modern Man has made a rubbish tip of Earth. He has increased his numbers to terrible proportions, has caused the death of hundreds of species of animals, has robbed and destroyed the planet in his search for fuels; now he stands, like a violent, spoilt child, delighted at the speed of his rise to power, on the edge of the final mass destruction and of killing all the life which exists in the solar system.
The Earth is our home but much of it is dirty and dying. Rapid industrial development caused a lot of ecological problems. They are: air pollution, water pollution, growth of population and shortage of mineral resources.
Air becomes polluted in many ways. Cars, trucks, buses, airplanes, factories and plants send burnt gases into the air. The production of electricity causes not only air pollution but acid rains and global warming. Because of acid rains the Earth looses twenty million acres of tropical rainforests every year. This means the extinction of thousands of species that live there, for example tigers. Only 67 thousand tigers remain. Tigers are hunted and killed for their body parts, which are used in oriental medicines. The ozone layer is destroyed too and the dangerous rays get through the atmosphere causing skin cancer and other diseases.