It is a small world we live in, and it is high time for all of us to realize it. Since ancient times people have been trying to produce more and more to increase human wealth. Nobody noticed that we were destroying Nature by using it as the source of raw materials, and as the garbage can for our waste. Nature seemed to be boundless and endless... Far from it as it turned out. Millions of cars and smoky factories pollute and spoil the air we breathe in. Pollution is hanging over big cities like an ugly brown cloud. It is hurting our lungs as well as the life of animals, birds and plants. People need wood and paper, so we cut down our forests. We don't know what to do with waste materials of our industry, so we pour them into water, bury them into soil, shoot them into atmosphere. We pollute the water we drink, and the land we live in. People build nuclear power stations and carry out nuclear tests. As a result, radiation represents one of the main problems nowadays. The rapid growth of population in the world may turn into another grave problem very soon. The speed with which we are using up our non-renewable resourses like oil and gas, is appaling. With the development of our civilization we have become dangerous to the planet and to ourselves. What must we do not to find ourselves in a dirty desert in the near future? This question cannot be ignored. Some scientists are pessimistic about our problems. They suppose that we have already reached the point of no return. Others are more optimistic and believe that our ecological problems are solvable because more and more people begin to understand how dangerous they are. There is increasing awareness of people of the real state of the planet. In many countries environmental protection agencies and research centres are set up. Such organizations as "Green Peace" and "Friends of the Earth" try to put pressure upon those governments that do not care for ecology in their countries. The humankind will be able to survive only if we all understand that environmental protection is our universal concern.