Environmental protection issue.

People always polluted their surroundings. But until now pollution was not such a serious problem. People lived in rural areas and did not produce such amount of polluting agents that would cause a dangerous situation in global scale. With the development of overcrowded industrial highly developed cities, which put huge amounts of pollutants into surrounds, the problem has become more and more dangerous. Acid rains, global warming, air and water pollution, and overpopulation are the problems that threaten human lives on the Earth.