With the intensification of human activities, the ozone layer on the earth's surface has become a serious hole,In 1974, it was discovered by Professor Roland (F.Sherwood Rowland) and Mullian (Mario Molina) of the University of California.

To protect the ozone layer is to protect the blue sky and protect life on earth. On January 23, 1995, the United Nations General Assembly decided that September 16 of each year is the International Day for the Protection of the Ozone Layer. All parties are required to take concrete actions to commemorate this day in accordance with the goals of the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments.

Fortunately, ozone depletion can be stopped or even restored on its own. To this end, the United Nations Environment Programme has convened various international conferences since 1976 and passed a series of resolutions to protect the ozone layer, limiting and phasing out ozone-depleting chemicals on a global scale.

Ozone has been discovered by humans for a hundred years. At an altitude of 15-25 kilometers from the surface of the earth, due to the exposure of the sun's ultraviolet rays, the ozone layer surrounding the outer space of the earth is formed. This thick ozone layer is the protective umbrella for human survival.

Ozone in the ozone layer is mainly produced by ultraviolet light. As we all know, the ultraviolet rays in the sun's rays are divided into long waves andShort-wave two, when the atmosphere (containing 21%) oxygen molecules by short-wave ultraviolet light, the oxygen molecules will be decomposed into atomic state.

If the ozone on the earth is compressed to 1 atmosphere, its thickness is only about 3mm, just like a "cosmic suit with a thickness of about 3mm". The atmospheric ozone layer has three main functions. One is the protective effect, the second is the heating effect, and the third is the role of greenhouse gases.

According to research, about 2.5 billion years ago, the earth did not have gas oxygen or very little, so the ultraviolet radiation in the sun can directly reach the earth's surface, the total energy of solar radiation, the ultraviolet region accounted for nearly 1.5. High-energy ultraviolet radiation plays an important role in the chemical evolution and even the chemical reaction of the birth of life.

Can the depletion of the ozone layer be stopped and can the ozone layer be restored? The answer is yes. Once the ozone-depleting substances in the stratosphere are reduced, the ozone layer can recover itself. Only in this way can it be restored to the natural balance of production and disappearance.[1]