Abstract

Ozone with three oxygen atoms is one of the vital atmospheric gases. It has either bad or good effects on the living system of Earth’s surface depending on its location in the atmosphere. In the lower atmosphere, ozone is formed by chemical reaction involving nitrogen oxides and volatile organic compounds and is a major component of air pollutants, which has harmful effects to plants, animals, and human beings. Ozone in the upper atmosphere is formed naturally by absorbing the Sun’s ultraviolet radiation and is beneficial to the living system, preventing these damaging radiations from reaching the Earth’s surface. However, observations of the upper atmosphere showed that ozone depletion was indeed occurring since the 1980s while more and more human-produced chemicals such as chlorofluorocarbons were steadily increasing in the atmosphere. Therefore, efforts need to be made to regulate the ozone-forming substances to reduce the ozone increase in the lower atmosphere. Meanwhile, more efforts have to be made to reduce human-produced ozone-depleting substances to recover the ozone depletion in the upper atmosphere.