With the rapid development of human civilization and the accelerated consumption of energy, the phenomenon of environmental pollution has also increased, corresponding to the fact that more and more people have begun to pay attention to environmental protection.
There will always be some people who disagree with everything, and environmental protection is no exception. In order to curb the greenhouse effect, many countries in the world signed the Paris Agreement in 2016, and the mainland also proposed a double carbon target of carbon peaking and carbon neutrality in 2020. Nevertheless, there are always those who believe that the "greenhouse effect" and "global warming" are deceptive, and they are based on the "ozone hole" that has not been mentioned for many years. Indeed, twenty or thirty years ago, when people mentioned environmental protection, the first thing that came to mind was the ozone hole, so why not mention it now? Is the ozone layer repaired, or is it a hoax?
First, it is certain that the ozone hole is real, and that it is indeed a serious environmental problem, by no means a hoax.
As for the evidence, it was the Montreal Protocol on Substances that Deplete the Ozone Layer. In 1987, more than 20 countries jointly signed the Montreal Protocol, and four years later, in 1991, China also acceded to the Protocol, and in 1994, the United Nations set September 16 as the "International Day for the Protection of the Ozone Layer". If the ozone hole is a scam, it's too much fun. Since the scam itself cannot be logically consistent, any scam, as long as the number of people involved is more than 1, then it will inevitably be exposed, it is only a matter of time, and if a scam involves dozens of countries, it is impossible to remain untouched for 30 years.
Since the ozone hole is not a hoax, why not mention it? Is it really fixed? Not so fast.
Ozone and oxygen we are familiar with have a lot in common, they are both elemental gases composed of oxygen atoms, the only difference is that oxygen is O2, and ozone is O3, that is, oxygen is composed of two oxygen atoms, and ozone is composed of three oxygen atoms. On Earth, oxygen is everywhere, it is one of the important components of the Earth's atmosphere, accounting for about 21% of the Earth's atmosphere, colorless and odorless. Although ozone is only one more oxygen atom than oxygen, it is no longer colorless and odorless, it is light blue, smells a little smelly, and is mostly concentrated in the stratosphere 20-25 kilometers from the ground.
Why is ozone so far away from us? Because the formation of ozone is indispensable to the participation of ultraviolet rays.
When the strong ultraviolet rays in the sunlight hit the Earth's high atmosphere, some of the oxygen will break down into oxygen atoms, which are themselves extremely unstable, and when they meet other oxygen molecules, they will combine with them to form ozone. The density of this gas is greater than the average density of air, so it will sink downwards, when they slowly sink to a position of about 20 kilometers from the ground, because they are supported by the troposphere below, so they stop here, and as more and more ozone sinks, gradually form a special gas layer, that is, the ozone layer.
The presence of the ozone layer is of great benefit to life on Earth.
Because of the occlusion of the ozone layer, life on Earth has avoided exposure to far-ultraviolet radiation, and without the ozone layer, the Earth's surface would never have been as vibrant as it is now. Under natural conditions, the thickness of the ozone layer can always be maintained within a certain range, because on the one hand, the ozone continues to generate and sink, on the other hand, the ozone that is once again exposed to ultraviolet rays will decompose and form oxygen due to its own instability, so the ozone layer has achieved a break-even. But although the development of human civilization, everything has become different, because human industrial production is indispensable to a compound, that is, HCFC compounds, which will produce chlorine atoms and bromine atoms under sunlight, and they will accelerate the decomposition of ozone, and over time the ozone layer will appear hollow.
The ozone hole is real, and the reason why it is not mentioned now is because the hole is being repaired.
Among the many HCFC compounds, Freon is the most harmful to the ozone layer, with the signing of the Montreal Protocol, countries around the world have begun to pay attention to the ozone hole, and scientists from all over the world have begun to look for alternatives to Freon, so the industrial use of Freon and various types of HCFC compounds are decreasing, and finally in 2006, the ozone hole over antarctica reached its maximum, and since then it has begun to be slowly repaired. Scientists predict that at the current rate of repair, the ozone hole over Antarctica will be able to return to the level of 1980 around 2050, and it will take longer to fill it all. In any case, this environmental problem has finally been solved in theory.