Mechanism of formation of ozone holes. The main sources of halogens are natural, not anthropogenic

One of the most remarkable "green" myths is the assertion that the ozone holes above the poles of the Earth arise due to the emissions of certain substances produced by man into the atmosphere. Thousands of people still believe in it, even though any student who has not skipped chemistry and geography classes can expose this myth.

The myth that human activity leads to the growth of the so-called ozone hole is remarkable in many ways. First, it is extremely plausible, that is, based on real facts. Such as the presence of the ozone hole itself and the fact that a number of substances produced by man can destroy ozone. And if so, then the non-specialist has no doubt that it is human activity that is to blame for the depletion of the ozone layer - just look at the graphs of the growth of the hole and the increase in emissions of the corresponding substances into the atmosphere.

And here one more feature of the "ozone" myth emerges. For some reason, those who believe the above evidence completely forget that the coincidence of the two graphs in itself does not mean anything. After all, it may just be a coincidence. In order to have indisputable evidence of the anthropogenic theory of the origin of ozone holes, it is necessary to study not only the mechanism of ozone destruction by freons and other substances, but also the mechanism of the subsequent restoration of the layer.

Well, here comes the most interesting part. As soon as an interested non-specialist begins to study all these mechanisms (for which one does not need to sit in the library for days - it is enough to recall a few paragraphs from school textbooks on chemistry and geography), he immediately understands that this version is nothing more than a myth. And remembering the impact this myth had on world economy, having limited the production of freons, he immediately understands why he was created. However, let's consider the situation from the very beginning and in order.

From the course of chemistry, we remember that ozone is an allotropic modification of oxygen. In its molecules, not two O atoms, but three. Ozone can be formed in different ways, but the most common in nature is as follows: oxygen absorbs a portion of ultraviolet radiation with a wavelength of 175-200 nm and 280-315 nm and is converted into ozone. This is how the protective ozone layer formed in ancient times (somewhere 2-1.7 billion years ago), and this is how it continues to form to this day.

By the way, it follows from the above that in fact, almost half of the dangerous UV radiation absorbs oxygen, not ozone. Ozone is only a "by-product" of this process. However, its value lies in the fact that it also absorbs part of the ultraviolet - the one whose wavelength is from 200 to 280 nm. But what happens to the ozone itself? That's right - it turns back into oxygen. Thus, in the upper layers of the atmosphere there is a certain cyclic equilibrium process - one type of ultraviolet contributes to the conversion of ozone into oxygen, and the latter, absorbing another type of UV radiation, again turns into O 2.

From all this follows a simple and logical conclusion - in order to completely destroy the ozone layer, you need to deprive our atmosphere of oxygen. After all, no matter how much freons produced by people (hydrocarbons containing chlorine and bromine used as refrigerants and solvents), methane, hydrogen chloride and nitrogen monoxide destroy ozone molecules, ultraviolet irradiation of oxygen will restore the ozone layer again - after all, these substances will “turn off” it unable! As well as reducing the amount of oxygen in the atmosphere, since trees, grasses and algae produce it hundreds of thousands of times more than humanity - the aforementioned ozone depleters.

So, as you can see, not a single substance created by people is able to destroy the ozone layer while there is oxygen in the Earth's atmosphere, and the Sun emits ultraviolet radiation. But why then do ozone holes appear? I want to say right away that the term "hole" itself is not entirely correct - we are talking only about the thinning of the ozone layer in certain parts of the stratosphere, and not about its complete absence. Nevertheless, in order to answer the question posed, one should simply remember where exactly on the planet the largest and most stable ozone holes exist.

And here there is nothing to remember: the largest of the stable ozone holes is located directly above Antarctica, and the other, slightly smaller, is located above the Arctic. All other ozone holes of the Earth are unstable, they are quickly formed, but just as quickly "darned". Why, then, in the polar regions, the thinning of the ozone layer persists for such a long time? Yes, simply because in these places the polar night lasts for six months. And during this time, the atmosphere over the Arctic and Antarctic does not receive enough ultraviolet radiation that can turn oxygen into ozone.

Well, O 3, in turn, left without "replenishment", begins to quickly collapse - after all, it is a very unstable substance. That's why the ozone layer over the poles is pretty thinner, although the process goes with some delay - a visible hole appears at the beginning of summer, and disappears by the middle of winter. However, when the polar day comes, ozone begins to be produced again and the ozone hole is slowly "darned". True, not completely - all the same, the time of intense receipt of UV radiation in these parts is shorter than the period of its deficiency. That is why the ozone hole does not disappear.

But why, in this case, was a myth created and replicated? The answer to this question is not that simple, but very simple. The fact is that for the first time the presence of a permanent ozone hole over Antarctica was proven in 1985. And at the end of 1986, specialists American company DuPont (that is, DuPont) launched the production of a new class of refrigerants - fluorocarbons that do not contain chlorine. This greatly reduced the cost of production, but the new substance still had to be promoted to the market.

And here "DuPont" finances the dissemination in the media of the myth about the evil freons that spoil the ozone layer, which, on his order, was composed by a group of meteorologists. As a result, a frightened public began to demand that the authorities take action. And these measures were taken at the end of 1987, when a protocol was signed in Montreal to limit the production of substances that destroy the ozone layer. This led to the ruin of many freon companies, as well as to the fact that DuPont long years became a monopoly in the refrigerant market.

By the way, it was precisely the speed of the DuPont management's decision to use the ozone hole for their own purposes that led to the fact that the myth turned out to be so unfinished that it could be exposed by an ordinary schoolboy who did not skip chemistry and geography classes. If they had more time - you see, they would have composed a more convincing version. Nevertheless, even what was finally "born" by scientists commissioned by DuPont was able to convince many people.

Earth is undoubtedly the most unique planet in our solar system. It is the only planet adapted for life. But we do not always appreciate it and believe that we are not able to change and disrupt what has been created over billions of years. In the entire history of existence, our planet has never received such loads that man gave it.

There is an ozone layer on our planet, which is so necessary for our life. It protects us from the effects of ultraviolet rays from the sun. Without him, life on this planet would not be possible.

Ozone is a blue gas with a characteristic odor. Each of us knows this pungent smell, which is especially audible after rain. No wonder ozone in Greek means "smelling". It is formed at a height of up to 50 km from the surface of the earth. But most of it is located at 22 - 24 km.

Causes of ozone holes

In the early 1970s, scientists began to notice a decrease in the ozone layer. The reason for this is the entry into the upper layers of the stratosphere of ozone-depleting substances used in industry, the launch of rockets, and many other factors. These are mainly chlorine and bromine molecules. Chlorofluorocarbons and other substances released by man reach the stratosphere, where, under the influence of sunlight, they decompose into chlorine and burn ozone molecules. It has been proven that one molecule of chlorine can burn 100,000 molecules of ozone. And it keeps in the atmosphere from 75 to 111 years!

As a result of falling ozone, ozone holes occur in the atmosphere. The first was discovered in the early 80s in the Arctic. Its diameter was not very large, and the fall in ozone was 9 percent.

Ozone hole in the Arctic

An ozone hole is a large drop in the percentage of ozone in certain places in the atmosphere. The very word "hole" makes us understand this without further explanation.

In the spring of 1985, in Antarctica, over the station Halle Bay, the ozone content dropped by 40%. The hole turned out to be huge and has already moved beyond the boundaries of Antarctica. In height, its layer reaches up to 24 km. In 2008, it was estimated that its size is already more than 26 million km2. It stunned the whole world. Is it clear? that our atmosphere is in greater danger than we thought. Since 1971, the ozone layer has fallen by 7% worldwide. As a result, ultraviolet radiation from the Sun, which is biologically dangerous, began to fall on our planet.

Consequences of ozone holes

Doctors believe that as a result of the decrease in ozone, the percentage of skin cancer and blindness due to cataracts has increased. Also, the human immunity decreases, which leads to various types other diseases. The inhabitants of the upper layers of the oceans suffer the most. These are shrimps, crabs, algae, plankton, etc.

An international agreement has now been signed by the United Nations to reduce the use of ozone-depleting substances. But even if you stop using them. it will take more than 100 years to close the holes.

Can the ozone holes be repaired?

To date, scientists have proposed one way to restore ozone using aircraft. To do this, it is necessary to release oxygen or artificially created ozone at an altitude of 12-30 kilometers above the Earth and disperse it with a special atomizer. So little by little the ozone holes can be filled. The disadvantage of this method is that it requires significant economic waste. In addition, it is impossible to release into the atmosphere at a time a large number of ozone. Also, the process of transporting ozone is complex and unsafe.

Myths about ozone holes

Since the problem of ozone holes remains open, several misconceptions have formed around it. Thus, the depletion of the ozone layer was sought to be turned into a fiction that is beneficial to industry, allegedly due to enrichment. On the contrary, all chlorofluorocarbon substances have been replaced with cheaper and safer components of natural origin.

Another false claim that supposedly ozone depleting freons are too heavy to reach the ozone layer. But in the atmosphere, all elements are mixed, and polluting components are able to reach the level of the stratosphere, in which the ozone layer is located.

You should not trust the statement that ozone is destroyed by halogens of natural origin, and not anthropogenic. This is not so, it is human activity that contributes to the release of various harmful substances that destroy the ozone layer. The consequences of the explosion of volcanoes and other natural disasters practically do not affect the state of ozone.

And the last myth is that ozone is destroyed only over Antarctica. In fact, ozone holes form everywhere in the atmosphere, causing the amount of ozone to decrease in general.

Forecasts for the future

Since the ozone holes have become, they have been closely monitored. Recently, the situation has become quite ambiguous. On the one hand, in many countries, small ozone holes appear and disappear, especially in industrialized areas, and on the other hand, there is a positive trend in the reduction of some large ozone holes.

In the course of observations, researchers recorded that the largest ozone hole hung over Antarctica, and it reached its maximum size in 2000. Since then, judging by the pictures taken by satellites, the hole has been gradually closing in. These statements are presented in the scientific journal Science. Environmentalists have calculated that its area has decreased by 4 million square meters. kilometers.

Studies show that gradually from year to year the amount of ozone in the stratosphere increases. This was facilitated by the signing of the Montreal Protocol in 1987. In accordance with this document, all countries are trying to reduce emissions into the atmosphere, reducing the amount of transport. China has been particularly successful in this regard. It regulates the emergence of new cars and there is the concept of a quota, that is, a certain number of car license plates can be registered per year. In addition, some progress has been made in improving the atmosphere, because gradually people are switching to alternative sources energy, there is a search for effective resources that would help save.

Since 1987, the problem of ozone holes has been raised more than once. This problem is devoted to many conferences and meetings of scientists. Issues are also discussed at meetings of state representatives. So in 2015, a conference was held in Paris, the purpose of which was to work out actions against climate change. This will also help reduce emissions into the atmosphere, which means that the ozone holes will gradually tighten. For example, scientists predict that by the end of the 21st century, the ozone hole over Antarctica will completely disappear.

Where are the ozone holes (VIDEO)

The ozone hole is considered to be a local drop in the ozone concentration in the Earth's ozone layer. Initially, experts assumed that the concentration of ozone tends to change due to particles that are emitted during any atomic explosion.

Causes of the appearance of ozone holes in the Earth's atmosphere long time considered high-altitude aircraft and spacecraft flights.

However, in the course of numerous studies and experiments, it has been proven that the ozone content can vary qualitatively due to certain natural air pollutants containing nitrogen.

The main reasons for the appearance of ozone holes

It has long been established that the main amount of natural ozone is contained at an altitude of 15 to 50 kilometers above the Earth's surface - in the stratosphere. Ozone brings the greatest benefit by absorbing a significant amount of ultraviolet solar radiation, which would otherwise be detrimental to living organisms on our planet. A decrease in the concentration of ozone in a certain place can be due to two types of air pollution. These include:

1. The natural processes by which air pollution occurs.
2. Anthropogenic pollution of the Earth's atmosphere.

Degassing processes are constantly carried out in the Earth's mantle, as a result of which a variety of organic compounds are released. Mud volcanoes and hydrothermal springs can generate these types of gases.

In addition, certain gases are located in the earth's crust, which are in a free state. Some of them are able to reach the earth's surface and diffuse into the atmosphere through cracks in the earth's crust. Therefore, surface air over oil and gas basins often contains elevated levels of methane. These types of pollution can be attributed to natural - occurring in connection with natural phenomena.

Anthropogenic air pollution can be caused by launches space rockets and supersonic jet flights. Also a large number of different chemical compounds is released into the atmosphere during the extraction and processing of numerous minerals from the bowels of the earth.

Large industrial cities, which are a kind of anthropogenic sources, also play a significant role in atmospheric pollution. Air masses in such areas are polluted by the extensive flow of road transport, as well as due to emissions from various industrial enterprises.

The history of the discovery of ozone holes in the atmosphere

The ozone hole was first discovered in 1985 by a group of British scientists led by Joe Farman. The diameter of the hole was more than 1000 kilometers, and it was located above Antarctica - in the Southern Hemisphere. Occurring annually in August, this ozone hole disappeared from December to January.

1992 was marked for scientists by the fact that already over the Northern Hemisphere in Antarctica another ozone hole was formed, with a much smaller diameter. And in 2008, the diameter of the first ozone phenomenon discovered in Antarctica reached its maximum record size - 27 million square kilometers.

Possible consequences of expanding ozone holes

Since the ozone layer is designed to protect the surface of our planet from an excess of ultraviolet solar radiation, ozone holes can be considered a phenomenon that is really dangerous for living organisms. A decrease in the ozone layer significantly increases the flow of solar radiation, which can affect the sharp increase in the number of skin cancers. No less detrimental is the appearance of ozone holes for plants and animals on Earth.

Thanks to public attention, the Vienna Convention for the Protection of the Ozone Layer was adopted in 1985. Then there was the so-called Montreal Protocol, adopted in 1987 and defining a list of the most dangerous chlorofluorocarbons. At the same time, the producing countries of these atmospheric pollutants pledged to limit their release, and by the year 2000 to stop altogether.

Hypotheses about the natural origin of the ozone hole

But Russian scientists have published confirmation of the hypothesis about the natural origin of the Antarctic ozone hole. In 1999, NPO Typhoon published a scientific work at Moscow State University, in which, according to the calculations of geophysicists A.P. Kapitsa and A.A. Gavrilov, the Antarctic ozone hole existed before it was discovered by direct experimental methods in 1982, which, according to Russian scientists, confirms the hypothesis of the natural origin of the ozone hole over Antarctica.

The authors of this scientific work were A.P. Kapitsa (corresponding member of the Russian Academy of Sciences) b A.A. Gavrilov (Moscow State University). The two scientists managed to establish that the number of facts contradicting the anthropogenic hypothesis of the origin of the Antarctic ozone hole is constantly growing, and after proving that the data on abnormally low values ​​of the total ozone in Antarctica in 1957-1959 are correct, it became clear that the cause of the ozone holes is different. from anthropogenic.

The results of research by Kapitsa and Gavrilov were published in Doklady Akademii Nauk, 1999, vol. 366, no. 4, p. 543-546

The earth is arranged in such a way that its unique ecosystem is preserved. These purposes are served by the layers of the atmosphere, which cover the planet from the penetration of ultraviolet rays, radiation, space debris. In nature, everything is perfect, and interference in its structure leads to various cataclysms and violation of the established order. At the end of the 20th century, a clear problem emerged that affects all of humanity. The ozone hole formed in the Antarctic region and attracted the attention of scientists from all over the world. The critical situation of ecology was aggravated by another serious problem.

It was found that in the ozone layer surrounding earth's surface, a gap was formed, the size of more than a thousand kilometers. Through it, radiation enters, adversely affecting people, animals and vegetation. Ozone holes and the thinning of the gas envelope were later discovered in several more places, which caused a stir in public circles.

The essence of the problem

Ozone is formed from oxygen, which is affected by ultra-violet rays. Due to this reaction, the planet is shrouded in a layer of gas through which radiation cannot enter. This layer is located at an altitude of 25-50 kilometers above the surface. The thickness of the ozone is not very large, but it is quite enough for all life to exist on the planet.

What is the ozone hole, learned in the 80s of the last century. This sensational discovery was made by British scientists. In places of ozone destruction, gas is not completely absent, its concentration decreases to a critical level of 30%. The gap formed in the stratosphere layer passes ultraviolet rays to the ground, which can burn living organisms.

The first such hole was discovered in 1985. Its location is Antarctica. The peak time when the ozone hole expanded was August, and by winter the gas condensed and practically closed the hole in the stratospheric layer. Critical points in height are located at a distance of 19 kilometers from the ground.

The second ozone hole appeared over the Arctic. Its dimensions were much smaller, but otherwise there was a striking resemblance. Critical heights and time of disappearance coincided. Currently, ozone holes appear in different places.

How does the thinning of the ozone layer occur?

Scientists attribute the occurrence of the problem with the thinning of the ozone layer to natural phenomena occurring at the poles. the globe. According to their theory, during the long polar nights, the sun's rays do not reach the earth, and ozone cannot be formed from oxygen. In this regard, clouds with a high content of chlorine are formed. It is he who destroys the gas so necessary to protect the planet.

The earth was going through a period of volcanic activity. It also had a detrimental effect on the thickness of the ozone layer. Emissions into the atmosphere of combustion products destroyed the already thin layer of the stratosphere. The release of freons into the air is another reason for the thinning of the protective layer of the earth.

The ozone hole disappears as soon as the sun begins to shine and interact with oxygen. at the expense air currents the gas rises and fills the resulting void. This theory proves that ozone circulation is constant and inevitable.

Other causes of ozone holes

Despite the fact that chemical processes play a dominant role in the formation of ozone holes, human impact on nature creates the main prerequisites. Naturally occurring chlorine atoms are not the only substances harmful to ozone. The gas is also destroyed by the action of hydrogen, bromine and oxygen. The reasons for the appearance of these compounds in the air lie in human activities on the planet. The preconditions are:

• operation of plants and factories;
• lack of treatment facilities;
• atmospheric emissions from thermal power plants;

A detrimental effect on the integrity of the atmosphere had nuclear explosions. Their consequences still affect the ecology of the planet. At the time of the explosion, great amount nitrogen oxides, which, rising, destroy the gas that protects the earth from radiation. Over 20 years of testing, more than three million tons have entered the atmosphere given substance.

devastating effect on the ozone layer jet planes. When fuel is burned in turbines, nitrogen oxides are thrown out, they directly enter the atmosphere and destroy gas molecules. Currently, out of a million tons of emissions of this substance, a third is accounted for by aircraft.

It would seem that mineral fertilizers are harmless and useful, but in fact they also adversely affect the atmosphere. When interacting with bacteria, they are processed into nitrous oxide, and then, under the influence of chemical reactions, change their shape and become oxides.

Thus, the ozone hole is the product of not only natural phenomena, but also . Rough decisions can lead to unexpected results.

Why is the disappearance of the ozone layer around the planet dangerous?

The sun is the source of heat and light for everything on the planet. Animals, plants and man flourish thanks to its life-giving rays. This has been noted by other people. ancient world who considered the sun-God to be the main idol. But the luminary can also cause the death of life on the planet.

Through the ozone holes formed under the influence of a tandem man and nature, solar radiation can fall to the ground and incinerate everything that was once grown. The detrimental effects on humans are obvious. Scientists have found that if the protective gas or its layer becomes thinner by one percent, then seven thousand more cancer patients will appear on earth. First of all, the skin of people will suffer, and then other organs.

The consequences of the formation of ozone holes affect not only humanity. Vegetation suffers, as well as animal world and inhabitants sea ​​depths. Them mass extinction is a direct consequence of the processes occurring on the sun and in the atmosphere.

Ways to solve the problem

The reasons for the appearance of ozone holes in the atmosphere are varied, but come down to one essential fact: thoughtless human activity and new technological solutions. Freons that enter the atmosphere and destroy its protective layer are a product of the combustion of various chemicals.

To stop these processes, fundamentally new scientific developments are needed that will allow production, heating, production and flight without the use of nitrogen, fluorine and bromine, as well as their derivatives.

The emergence of the problem is associated with careless production and agricultural activities. It's time to think:

• on the installation of treatment facilities on smoking chimneys;
• on the replacement of chemical fertilizers with organic ones;
• on the transition of transport to electricity.

Quite a lot has been done over the past sixteen years, since 2000. Scientists managed to achieve amazing results: the size of the ozone hole over Antarctica has decreased by an area equal to the territory of India.

Consequences of negligent and inattentive attitude to environment are already making themselves known. In order not to aggravate the situation even more, it is necessary to deal with the problem at the global level.