Today the greatest problem for humanity is pollution. The pollution of land, air and water threatens the nature.Air becomes polluted in many ways. There are a lot of industrial enterprises in the world. And uncontrolled emissions (gases, smokes, dirty water) of harmful substances and dust from metallurgical plants, steel mills, mines, chemical plants and factories pollute everything around us.​It is worth mentioning that one third of all emission into the atmosphere originates from transport.Thermal and nuclear power stations are also a great source of pollution. Radiation has become one of the main problems. In 1986 the Chernobyl nuclear power plant disaster poisoned significant areas of agricultural and forest lands of Ukraine, Belarus and Russia for 8 000 years.Another problem is wastes. The wastes from plants and factories contaminate water and soil. Household wastes such as all kinds of plastics, dead batteries and so on remain unruined for decades.  Another reason of soil poisoning is the use of fertilizers, which are harmful for a man.These are only some of the problems of the environment: acid rains, ozone holes, greenhouse effect, which brings us global warming and rises sea level.All these factors and pollutions threaten mankind and nature. They hurt people health, cause bad diseases and illnesses, reduce people life and even kill them; some kinds of animals and plants have already disappeared.Our environment must be clean. We have to control atmosphere and water pollution, to study the man’s influence on the climate. It is necessary to use purification equipment and the closed cycle use of water, look for wasteless technologies, to find the way of waste recycling, learn to use natural sources of energy, such as the energy of wind, sun, the energy of ebb and flow and look for new safe sources of energy.  We have to realize that the Earth is in danger. And we can stop killing the Earth and mankind only working together.