However, the reason why the sun has so many benefits to us is because the disadvantages of the sun are blocked by the earth's protective shield. The protective shield is the ozone layer, the new little friend of the earth born 600 million years ago.

The ozone layer is protecting the earth

The ozone layer simply exists for our survival. As mentioned earlier, the sun has huge energy, and the ultraviolet rays it emits are particularly harmful to the human body. Excessive ultraviolet rays entering the human body can cause skin cancer . The ozone layer has the function of absorbing ultraviolet rays. Of course, it does not absorb all the ultraviolet rays, but leaves 1% of the ultraviolet rays. This small amount of ultraviolet rays allows humans to adapt and benefit. Ultraviolet rays can not only sterilize, but also promote the synthesis of vitamins in the human body.

However, the ozone layer, which has been protecting the earth for 600 million years, was found to have a hole in 1984!

The dangers of the ozone layer hole

The role of the ozone layer as a protective shield for the earth is self-evident. Once the ozone layer disappears, the situation of life on earth will be very dangerous.

During the Ordovician period 440 million years ago, a gamma ray burst hit the earth, causing the ozone layer to dissolve. This was a terrible moment. A large number of plankton in the ocean died and the food chain was severely damaged. This tragic situation lasted for 400,000 years, leading to the extinction of 85% of all living things. It is called one of the five mass extinction events!

Gamma ray burst

Of course, the harm caused by the hole in the Antarctic ozone layer is far from what it was back then, but we cannot take it lightly. Because of the hole, the amount of ultraviolet rays counteracted by the ozone layer is reduced, and excessive ultraviolet rays are likely to cause skin cancer. According to calculations, for every 1% decrease in ozone , the number of skin cancer patients will increase by 4%-6%. It’s really not good news for fur-protected humans. Excessive ultraviolet rays can also damage our body's immune system. Long-term exposure can reduce immunity. If it is exposed to the eyes, there is a possibility of cataracts. It is also possible that, just like the time in the Ordovician , a large amount of ultraviolet rays will kill the plankton in the ocean. This will cause some of the organisms that feed on them to starve and their numbers will decrease sharply. One after another, The number of predators that these creatures feed on will also decrease due to the decrease in food, and a vicious cycle begins! When a hole is created in the ozone layer, the sun's energy cannot be reduced, and the temperature hitting the surface of the earth will rise. When the temperature rises, glaciers will melt, sea levels will rise, and coastal cities will suffer a devastating blow. This is why we as humans We can not be ignored.

Ozone layer hole

It can be seen that the ozone layer does play an irreplaceable role on the earth. The ozone layer hole discovered in Antarctica also sounded the alarm for people at that time to protect the environment.

Since the harm caused by the hole in the ozone layer is so great, how did it occur?

At the beginning of the 21st century, there was a lot of publicity recommending not to buy refrigerators that use Freon as the refrigerant. This is because the vast majority of scientists believe that chloride ions are the culprits of destroying the ozone layer. Freon is composed of carbon, chlorine, and fluorine, and chlorofluorocarbons such as , chlorofluorocarbons, and are the main cause of the ozone layer hole over Antarctica. During use, Freon decomposes into chlorine ions, and then after the chlorine ions enter the atmosphere, they can It repeatedly destroys ozone molecules in the ozone layer without consuming itself, so many people believe that the Antarctic hole was caused by the extensive use of Freon.

Freon refrigerant

But some scientists disagree with this idea. They believe that Freon's ability to destroy ozone molecules is very subtle. After Freon was invented by Thomas Midgley of the United States in 1930, it was not until 1980 It has only just begun to be used on a large scale, so in the four years since the Antarctic ozone layer hole was discovered in 1984, it was impossible for Freon to produce such a powerful force. But the scientific community continues to debate who is to blame. Until Mr. Yang Xuexiang, a professor at the School of Earth Exploration Science and Technology of Jilin University in my country, proposed in 1999 that solar wind, solar radiation and solar tidal force are the main factors that produce the Antarctic ozone hole. This argument is solid and supported by many people. .

Thomas Midgley

Of course, we cannot change what the particles emitted by the solar wind do at the geomagnetic poles, but we can restrain ourselves from using products made of chlorofluorocarbons and other chlorofluorocarbons. Although chloride ion is not the main cause, it can indeed cause harm to ozone molecules, so why don't we eradicate this situation as best we can? The United Nations Environment Program also made a series of regulations. In 1987, many countries signed the Monterey Treaty to control and reduce other ozone-depleting substances as early as possible. Many refrigerator manufacturers have also launched the fluorine-free refrigerator . This kind of refrigerator uses R134a refrigerant or R600a refrigerant to replace the former R-12 Freon, contributing to ecological and environmental protection. How to judge whether your refrigerator is fluorine-free? We can check the refrigerant type label on the nameplate of the refrigerator. Among them, the refrigerant of R12 or R22 is Freon, which means there is a fluorine refrigerator. Refrigerators with other refrigerants such as R600a or 134a are fluorine-free refrigerators. , go and take a look. !

As for why few people pay attention to the Antarctic ozone layer hole incident now, many people think that what was spread before is all rumors and lies. But that’s not the case, and it’s because of a huge good thing: scientists have discovered that the Antarctic ozone layer is repairing itself.

For example, in 2006, the area of ​​the ozone layer hole was 27.5 million square kilometers. In 2007, the hole area was 24.09 million square kilometers. It can be seen that the control of Freon is still effective. Perhaps by the end of this century, the Antarctic ozone layer hole will disappear. Completely restored, which is why no one is talking about the void these days.

Changes in the Hole in the Ozone Layer

I have to say that this victory is not achieved by a small number of people alone. It is the result of the persistence and improvement of our entire humanity. This experience of all mankind working together to advance towards a goal also makes us understand that the power of one person is too weak after all. Only when everyone unites can we exert our greatest strength. Perhaps one day in the future, we humans will strive with the same values, develop together for the sake of the earth and ourselves, and truly form a community with a shared future for mankind in which "you have me, and I have you". I believe that day will not be too late!