The appearance of ozone holes leads to. The problem of ozone holes

“We can, perhaps, say that the purpose of man is, as it were, to destroy his race, having first made the globe uninhabitable.”

J.B. Lamarck.

Since the formation of a highly industrialized society, dangerous human intervention in nature has sharply increased, it has become more diverse and threatens to become a global danger to humanity. A real threat of a global environmental crisis looms over the world, understood by the entire population of the planet. The real hope for its prevention lies in continuous environmental education and enlightenment of people.

The main reasons leading to environmental disaster can be identified:

· pollution;

· poisoning of the environment;

· depletion of the atmosphere in oxygen;

· formation of ozone “holes”.

This message summarizes some literature data on the causes and consequences of the destruction of the ozone layer, as well as ways to solve the problem of the formation of “ozone holes”.

Chemical and biological characteristics of ozone

Ozone is an allotropic modification of oxygen. The nature of the chemical bonds in ozone determines its instability (after a certain time, ozone spontaneously turns into oxygen: 2O 3 → 3O 2) and high oxidizing ability. The oxidative effect of ozone on organic substances is associated with the formation of radicals: RH + O 3 → RО 2. +OH.

These radicals initiate radical chain reactions with bioorganic molecules (lipids, proteins, nucleic acids), which leads to cell death. Application of ozone for sterilization drinking water based on its ability to kill germs. Ozone is also important for higher organisms. Prolonged exposure to environments containing ozone (for example, physical therapy and quartz irradiation) may cause severe impairment nervous system. Therefore, ozone in large doses is a toxic gas. Maximum permissible concentration in the air working area– 0.1 mg/m3.

There is very little ozone, which smells so wonderful during a thunderstorm, in the atmosphere - 3-4 ppm (per mille) - (3-4) * 10 -4%. However, its presence is extremely important for the flora and fauna of the planet. After all, life that originated in the ocean depths was able to “crawl” onto land only after the ozone shield was formed 600–800 million years ago. By absorbing biologically active solar ultraviolet radiation, it ensured its safe level on the surface of the planet. Life on Earth is unthinkable without the ozone layer, which protects all living things from harmful ultraviolet radiation Sun. The disappearance of the ozonosphere would lead to unpredictable consequences - an outbreak of skin cancer, the destruction of plankton in the ocean, mutations of flora and fauna. Therefore, it is so important to understand the causes of the ozone “hole” over Antarctica and the decrease in ozone levels in the Northern Hemisphere.

Ozone is formed in the upper stratosphere (40-50 km) during photochemical reactions involving oxygen, nitrogen, hydrogen and chlorine. Atmospheric ozone is concentrated in two areas - the stratosphere (up to 90%) and the troposphere. As for the tropospheric ozone layer distributed at an altitude of 0 to 10 km, it is precisely due to uncontrolled industrial emissions that it is becoming more and more abundant. In the lower stratosphere (10-25 km), where ozone is highest, main role the processes of air mass transfer play a role in seasonal and longer-term changes in its concentration.

The thickness of the ozone layer over Europe is decreasing at a rapid pace, which cannot but worry the minds of scientists. Over the past year, the thickness of the ozone “coating” has decreased by 30%, and the rate of deterioration of natural containment reached its highest level in the last 50 years. Determined that chemical reactions Ozone-depleting emissions occur on the surface of ice crystals and any other particles trapped in the high stratosphere above the polar regions. What danger does this pose to humans?

Thin ozone layer(2-3 mm when distributed around the globe) is unable to prevent the penetration of short-wave ultraviolet rays, which cause skin cancer and are dangerous to plants. Therefore, today, due to the high activity of the sun, sunbathing has become less useful. In general, environmental centers should give recommendations to the population on how to act depending on the activity of the sun, but in our country there is no such center.

Climate change is associated with a decrease in the ozone layer. It is clear that changes will occur not only in the area over which the ozone hole “stretches”. The chain reaction will entail changes in many deep processes of our planet. This does not mean that rapid global warming will begin everywhere, as they scare us in horror films. Still, this is too complex and time-consuming process. But other disasters may arise, for example, the number of typhoons, tornadoes, and hurricanes will increase.

It has been established that “holes” in the ozone layer appear over the Arctic and Antarctica. This is explained by the fact that acid clouds form at the poles, destroying the ozone layer. It turns out that ozone holes arise not from the activity of the sun, as is commonly believed, but from the daily activities of all the inhabitants of the planet, including you and me. Then the “acid gaps” shift, most often to Siberia.

Using new mathematical model It was possible to link together data from ground-based, satellite and aircraft observations with the levels of likely future emissions of ozone-depleting compounds into the atmosphere, the timing of their transport to Antarctica and weather in southern latitudes. Using the model, a forecast was obtained according to which the ozone layer over Antarctica will recover in 2068, and not in 2050, as was believed.

It is known that currently the level of ozone in the stratosphere over areas far from the poles is approximately 6% below normal. At the same time, in spring period Ozone levels over Antarctica may decrease by 70% relative to the annual average. New model makes it possible to more accurately predict the levels of ozone-depleting gases over Antarctica and their temporal dynamics, which determine the size of the ozone “hole.”

The use of ozone depleting substances is limited by the Montreal Protocol. It was believed that this would lead to a rapid “tightening” of the ozone hole. However, new research has shown that in reality the rate of decline will only become noticeable in 2018.

History of ozone research

The first observations of ozone date back to 1840, but the ozone problem received rapid development in the 20s of the last century, when special ground stations appeared in England and Switzerland.

An additional way to study the connections between ozone transfer and atmospheric stratification has been opened by aircraft soundings of atmospheric ozone and releases of ozone probes. New era marked by the emergence of artificial Earth satellites that observe atmospheric ozone and provide a wealth of information.

In 1986, the Montreal Protocol was signed to limit the production and consumption of ozone-depleting substances that deplete the ozone layer. To date, 189 countries have joined the Montreal Protocol. Time limits have been established for the cessation of production of other ozone-depleting substances. According to model forecasts, if the Protocol is observed, the level of chlorine in the atmosphere will decrease by 2050 to the level of 1980, which could lead to the disappearance of the Antarctic “ozone hole”.

Reasons for the formation of the “ozone hole”

In summer and spring, ozone concentrations increase. It is always higher over the polar regions than over the equatorial ones. In addition, it changes on an 11-year cycle, coinciding with the solar activity cycle. All this was already well known when in the 1980s. Observations have shown that over Antarctica there is a slow but steady decrease in stratospheric ozone concentrations from year to year. This phenomenon was called the “ozone hole” (although, of course, there was no hole in the proper sense of the word).

Later, in the 90s of the last century, the same decrease began to occur over the Arctic. The phenomenon of the Antarctic “ozone hole” is not yet clear: whether the “hole” arose as a result of anthropogenic pollution of the atmosphere, or whether it is a natural geoastrophysical process.

Among the versions of the formation of ozone holes are:

influence of particles emitted during atomic explosions;

· flights of rockets and high-altitude aircraft;

· reactions of certain substances produced by chemical plants with ozone. These are primarily chlorinated hydrocarbons and especially freons - chlorofluorocarbons, or hydrocarbons in which all or most of the hydrogen atoms are replaced by fluorine and chlorine atoms.

Chlorofluorocarbons are widely used in modern household and industrial refrigerators (that’s why they are called “freons”), in aerosol cans, as chemical cleaning agents, for extinguishing fires in transport, as foaming agents, for the synthesis of polymers. World production of these substances has reached almost 1.5 million tons/year.

Being highly volatile and quite resistant to chemical influences, chlorofluorocarbons enter the atmosphere after use and can remain in it for up to 75 years, reaching the height of the ozone layer. Here, under the influence of sunlight, they decompose, releasing atomic chlorine, which serves as the main “disturber of order” in the ozone layer.

The widespread use of fossil resources is accompanied by the release into the atmosphere large masses various chemical compounds. Most anthropogenic sources are concentrated in cities, occupying only a small part of the territory of our planet. As a result of the movement of air masses from the leeward side big cities a multi-kilometer plume of pollution is formed.

The sources of air pollution are:

1) Road transport. It can be assumed that the contribution of transport to air pollution will increase as the number of cars increases.

2) Industrial production. The basic products of basic organic synthesis are ethylene (almost half of all organic substances are produced on its basis), propylene, butadiene, benzene, toluene, xylenes and methanol. In emissions from chemical and petrochemical industry There is a wide range of pollutants: components of the feedstock, intermediate, by-products and target synthesis products.

3) Aerosols. Chlorofluorocarbons (freons) are widely used as volatile components (propellants) in aerosol packages. About 85% of freons were used for these purposes and only 15% in refrigeration units and artificial climate installations. The specificity of using freons is such that 95% of their quantity enters the atmosphere 1-2 years after production. It is believed that almost the entire amount of freon produced must sooner or later enter the stratosphere and be included in the catalytic cycle of ozone destruction.

The earth's crust contains various gases in a free state, sorbed by different rocks and dissolved in water. Some of these gases reach the Earth's surface through deep faults and cracks and diffuse into the atmosphere. The existence of hydrocarbon respiration in the earth's crust is indicated by the increased methane content in the ground layer of air above oil and gas basins compared to the global background.

Studies have shown that the gases of Nicaragua's volcanoes contain noticeable amounts of HF. Analysis of air samples taken from the crater of the Masaya volcano also showed the presence of freons along with other organic compounds. Halocarbons are also present in gases from hydrothermal vents. These data required evidence that the detected hydrofluorocarbons were not of anthropogenic origin. And such evidence was obtained. Freons have been discovered in air bubbles in 2,000-year-old Antarctic ice. NASA specialists undertook a unique study of the air from a hermetically sealed lead coffin, discovered in Maryland and reliably dated to the 17th century. Freons were also found in it. Another confirmation of the existence of a natural source of freons was “raised” from the seabed. CFCl 3 was found in water recovered in 1982 from a depth of more than 4000 meters in the equatorial region Atlantic Ocean, at the bottom of the Aleutian Trench and at a depth of 4500 meters off the coast of Antarctica.

Misconceptions about ozone holes

There are several widespread myths regarding the formation of ozone holes. Despite their unscientific nature, they often appear in the media - sometimes out of ignorance, sometimes supported by conspiracy theorists. Some of them are listed below.

1) The main ozone destroyers are freons. This statement is true for middle and high latitudes. In the rest, the chlorine cycle is responsible for only 15-25% of ozone loss in the stratosphere. It should be noted that 80% of chlorine is of anthropogenic origin. That is, human intervention greatly increases the contribution of the chlorine cycle. Before human intervention, the processes of ozone formation and destruction were in equilibrium. But freons emitted during human activity, shifted this equilibrium towards a decrease in ozone concentration. The mechanism of ozone destruction in the polar regions is fundamentally different from that at higher latitudes; the key stage is the conversion of inactive forms of halogen-containing substances into oxides, which occurs on the surface of particles of polar stratospheric clouds. And as a result, almost all ozone is destroyed in reactions with halogens (chlorine is responsible for 40-50% and bromine is responsible for about 20-40%).

2) Freons are too heavy to reach the stratosphere .

3) The main sources of halogens are natural, not anthropogenic

Sources of chlorine in the stratosphere

It is believed that natural sources of halogens, such as volcanoes or oceans, are more significant for the process of ozone destruction than those produced by humans. Without questioning the contribution natural sources into the overall balance of halogens, it should be noted that they generally do not reach the stratosphere due to the fact that they are water-soluble (mainly chloride ions and hydrogen chloride) and are washed out of the atmosphere, falling as rain on the ground.

4) The ozone hole must be located above the sources of freons

Dynamics of changes in the size of the ozone hole and ozone concentration in Antarctica by year.

The reasons why the ozone hole forms in Antarctica are related to the local climate. Low temperatures Antarctic winters lead to the formation of a polar vortex. The air inside this vortex moves mainly along closed trajectories around the South Pole. At this time, the polar region is not illuminated by the Sun, and ozone does not arise there. With the arrival of summer, the amount of ozone increases and returns to its previous level. That is, fluctuations in ozone concentration over Antarctica are seasonal. However, if we trace the yearly averaged dynamics of changes in ozone concentration and the size of the ozone hole over the past decades, then there is a strictly defined tendency for ozone concentration to fall.

5) Ozone is only destroyed over Antarctica

Dynamics of changes in the ozone layer over Arosa, Switzerland

This is not true; ozone levels are also falling throughout the atmosphere. This is shown by the results of long-term measurements of ozone concentrations in different parts of the planet. You can look at the graph of changes in ozone concentration over Arosa (Switzerland).

Ways to solve problems

To begin global recovery, it is necessary to reduce the access to the atmosphere of all substances that very quickly destroy ozone and are stored there for a long time. People need to understand this and help nature start the process of restoring the ozone layer; in particular, new forest plantings are needed.

To restore the ozone layer, it needs to be recharged. At first, for this purpose, it was planned to create several ground-based ozone factories and “throw” ozone into the upper layers of the atmosphere on cargo planes. However, this project (probably it was the first project to “treat” the planet) was not implemented. A different way is proposed by the Russian consortium Interozon: producing ozone directly in the atmosphere. In the near future, together with the German company Daza, it is planned to raise balloons with infrared lasers to a height of 15 km, with the help of which they can produce ozone from diatomic oxygen. If this experiment turns out to be successful, in the future it is planned to use the experience of the Russian orbital station"Mir" and create several space platforms with energy sources and lasers at an altitude of 400 km. Laser beams will be directed into the central part of the ozone layer and will constantly replenish it. The energy source can be solar panels. Astronauts on these platforms will only be required for periodic inspections and repairs.

Time will tell whether the grandiose peace project will be realized.

Taking into account the emergency of the situation, it seems necessary:

Expand the complex of theoretical and experimental research on the problem of preserving the ozone layer;

Create an International Fund for the Preservation of the Ozone Layer through active means;

Organize International Committee to develop a strategy for the survival of humanity in extreme conditions.

Bibliography

1. (ru -).

2. ((cite web - | url = http://www.duel.ru/200530/?30_4_2 - | title = “Duel” Is it worth it? - | accessdate = 07/3/2007 - | lang = ru - ) )

3. I.K.Larin. The ozone layer and the Earth's climate. Errors of the mind and their correction.

4. National Academy of SciencesHalocarbons: Effects on Stratospheric Ozone. - 1976.

5. Babakin B. S. Refrigerants: history of appearance, classification, application.

6. Magazine "Ecology and Life". Article by E.A. Zhadina, candidate of physical and mathematical sciences.

Introduction

An ozone hole with a diameter of over 1000 km was first discovered in 1985 in the Southern Hemisphere of Antarctica by a group of British scientists. Every August it appeared, ceasing to exist by December or January. Another smaller hole was forming over the Northern Hemisphere in the Arctic.

The ozone hole- a local drop in the concentration of ozone-ozone layer of the Earth. According to the generally accepted theory in the scientific community, in the second half of the 20th century, the ever-increasing impact anthropogenic factor in the form of the release of chlorine- and bromine-containing freons has led to a significant thinning of the ozone layer, see, for example, the report of the World Meteorological Organization:

These and other recent scientific data strengthen the conclusion of previous assessments that the preponderance of scientific evidence indicates that observed ozone loss at mid- and high-latitudes is primarily due to anthropogenic chlorine- and bromine-containing compounds

According to another hypothesis, the process of formation of “ozone holes” may be largely natural and not associated solely with the harmful effects of human civilization.

Education mechanism

A combination of factors leads to a decrease in ozone concentration in the atmosphere, the main of which is the death of ozone molecules in reactions with various substances of anthropogenic and natural origin, the absence of solar radiation during the polar winter, a particularly stable polar vortex that prevents the penetration of ozone from subpolar latitudes, and the formation polar stratospheric clouds (PSC), the surface of which particles catalyze ozone decay reactions. These factors are especially characteristic of the Antarctic; in the Arctic, the polar vortex is much weaker due to the absence of a continental surface, the temperature is several degrees higher than in the Antarctic, and PSOs are less common and also tend to disintegrate in early autumn. Being chemically active, ozone molecules can react with many inorganic and organic compounds. The main substances that contribute to the destruction of ozone molecules are simple substances (hydrogen, oxygen atoms, chlorobromine), inorganic (hydrogen chloride, nitrogen monoxide) and organic compounds (methane, fluorochlorine and fluorobromofreons, which release chlorine and bromine atoms). In contrast, for example, to hydrofluorofreons, which decompose into fluorine atoms, which, in turn, quickly react to form stable hydrogen fluoride. Thus, fluorine does not participate in ozone decomposition reactions. Iodine also does not destroy stratospheric ozone, since iodine-containing organic substances are almost completely consumed in the troposphere. The main reactions that contribute to the destruction of ozone are given in the article pro-ozone layer.

Consequences

The weakening of the ozone layer increases the flow of solar radiation onto the earth and causes an increase in the number of skin cancers in people. Plants and animals also suffer from increased levels of radiation.

Restoring the ozone layer

Although humanity has taken measures to limit emissions of chlorine- and bromine-containing freons by switching to other substances, such as fluorine-containing freons , the process of restoring the ozone layer will take several decades. First of all, this is due to the huge volume of freons already accumulated in the atmosphere, which have a lifetime of tens and even hundreds of years. Therefore, the ozone hole should not be expected to close until 2048.

Misconceptions about the ozone hole

There are several widespread myths regarding the formation of ozone holes. Despite their unscientific nature, they often appear in the media - sometimes due to ignorance, sometimes supported by supporters conspiracy theories. Some of them are listed below.

Freons are the main ozone destroyers

This statement is true for middle and high latitudes. In the rest, the chlorine cycle is responsible for only 15-25% of ozone loss in the stratosphere. It should be noted that 80% of chlorine is of anthropogenic origin. (for more details about the contribution of various cycles, see Art. ozone layer). That is, human intervention greatly increases the contribution of the chlorine cycle. And with the existing tendency to increase the production of freons before the entry into force Montreal Protocol(10% per year) 30 to 50% of total ozone loss in 2050 would be due to exposure to CFCs. Before human intervention, the processes of ozone formation and destruction were in equilibrium. But freons emitted by human activity have shifted this balance towards a decrease in ozone concentration. As for the polar ozone holes, the situation here is completely different. The mechanism of ozone destruction is fundamentally different from higher latitudes, the key stage being the conversion of inactive forms of halogen-containing substances into oxides, which occurs on the surface of particles of polar stratospheric clouds. And as a result, almost all ozone is destroyed in reactions with halogens, chlorine is responsible for 40-50% and bromine is responsible for about 20-40%.

DuPont initiated a ban on old and the transition to new types of freons because their patent was expiring

DuPont, after publishing data on the participation of freons in the destruction of stratospheric ozone, took this theory with hostility and spent millions of dollars on a press campaign to protect freons. Chairman DuPont wrote in an article in Chemical Week on July 16, 1975, that the theory of ozone depletion was science fiction, nonsense, and made no sense. Except DuPont whole line companies around the world have produced and are producing various types of freons without royalty payments

Freons are too heavy to reach the stratosphere

It is sometimes argued that since freon molecules are much heavier than nitrogen and oxygen, they cannot reach the stratosphere in significant quantities. However, atmospheric gases are completely mixed and not separated or sorted by weight. Estimates of the required time for the diffusion stratification of gases in the atmosphere require times of the order of thousands of years. Of course, in a dynamic atmosphere this is impossible. The processes of vertical mass transfer, convection, and turbulence completely mix the atmosphere below the turbopause much faster. Therefore, even such heavy gases as inert freons are evenly distributed in the atmosphere, including reaching the stratosphere. Experimental measurements of their concentrations in the atmosphere confirm this, see, for example, on the right, the graph of the distribution of CFC-11 freon by height. Measurements also show that it takes about five years for gases released on the Earth's surface to reach the stratosphere, see the second graph on the right. If the gases in the atmosphere did not mix, then such heavy gases from its composition as carbon dioxide would form a layer several tens of meters thick on the Earth’s surface, which would make the Earth’s surface uninhabitable. Fortunately, this is not the case. Ikrypton, with an atomic mass of 84, and helium, with an atomic mass of 4, have the same relative concentration, both near the surface and up to 100 km altitude. Of course, all of the above is true only for gases that are relatively stable, such as freons or inert gases. Substances that react and are also subject to various physical influences, say, dissolve in water, have a concentration dependence on altitude.

The main sources of halogens are natural, not anthropogenic

It is believed that natural sources of halogens, such as volcanoes and oceans, are more significant for the process of ozone destruction than those produced by humans. Without questioning the contribution of natural sources to the overall balance of halogens, it should be noted that they generally do not reach the stratosphere due to the fact that they are water-soluble (mainly chloride ions and hydrogen chloride) and are washed out of the atmosphere, falling as rain on the ground. Also, natural compounds are less stable than freons; for example, methyl chloride has an atmospheric lifetime of only about a year, compared to tens and hundreds of years for freons. Therefore, their contribution to the destruction of stratospheric ozone is quite small. Even the rare eruption of Mount Pinatubo in June 1991 caused a drop in ozone levels not due to the release of halogens, but due to the formation large mass sulfuric acid aerosols, the surface of which catalyzed ozone destruction reactions. Fortunately, after just three years, almost the entire mass of volcanic aerosols was removed from the atmosphere. Thus, volcanic eruptions are relatively short-term factors affecting the ozone layer, in contrast to freons, which have lifetimes of tens and hundreds of years.

The ozone hole must be located above the sources of freons

Many people do not understand why the ozone hole forms in Antarctica when the main emissions of CFCs occur in the Northern Hemisphere. The fact is that freons are well mixed in the troposphere and stratosphere. Due to their low reactivity, they are practically not consumed in the lower layers of the atmosphere and have a lifespan of several years or even decades. Therefore, they easily reach the upper layers of the atmosphere. The Antarctic “ozone hole” does not exist forever. It appears at the end of winter - beginning of spring. The reasons why the ozone hole forms in Antarctica are related to the local climate. The low temperatures of the Antarctic winter lead to the formation of a polar vortex. The air inside this vortex moves mainly along closed trajectories around the South Pole. At this time, the polar region is not illuminated by the Sun, and ozone does not arise there. With the arrival of summer, the amount of ozone increases and returns to its previous level. That is, fluctuations in ozone concentration over Antarctica are seasonal. However, if we trace the yearly averaged dynamics of changes in ozone concentration and the size of the ozone hole over the past decades, then there is a strictly defined tendency for ozone concentration to fall.

Ozone is only destroyed over Antarctica

Dynamics of changes in the ozone layer over Arosa, Switzerland

This is not true; ozone levels are also falling throughout the atmosphere. This is shown by the results of long-term measurements of ozone concentrations in different parts of the planet. You can look at the graph of ozone concentrations over Arosa in Switzerland on the right.

The first thing to be clear is that the ozone hole, contrary to its name, is not a hole in the atmosphere. The ozone molecule differs from an ordinary oxygen molecule in that it consists of not two, but three oxygen atoms connected to each other. In the atmosphere, ozone is concentrated in the so-called ozone layer, at an altitude of approximately 30 km within the stratosphere. In this layer, ultraviolet rays emitted by the Sun are absorbed, otherwise solar radiation could cause great harm life on the surface of the Earth. Therefore, any threat to the ozone layer deserves to be taken very seriously. In 1985, British scientists working at the South Pole discovered that during the Antarctic spring, the level of ozone in the atmosphere there was significantly below normal. Every year at the same time, the amount of ozone decreased—sometimes to a greater extent, sometimes to a lesser extent. Similar, but less pronounced ozone holes also appeared over the North Pole during the Arctic spring.

In subsequent years, scientists figured out why the ozone hole appears. When the sun goes down and the long polar night begins, temperatures plummet and high stratospheric clouds containing ice crystals form. The appearance of these crystals causes a series of complex chemical reactions leading to the accumulation of molecular chlorine (a chlorine molecule consists of two joined chlorine atoms). When the sun appears and the Antarctic spring begins, under the influence of ultraviolet rays, intramolecular bonds are broken, and a stream of chlorine atoms rushes into the atmosphere. These atoms act as catalysts for reactions that convert ozone into simple oxygen, proceeding according to the following dual scheme:

Cl + O 3 -> ClO + O 2 and ClO + O -> Cl + O 2

As a result of these reactions, ozone molecules (O 3) are converted into oxygen molecules (O 2), with the original chlorine atoms remaining in a free state and again participating in this process (each chlorine molecule destroys a million ozone molecules before they are removed from the atmosphere under by other chemical reactions). As a result of this chain of transformations, ozone begins to disappear from the atmosphere over Antarctica, forming an ozone hole. However, soon, with warming, the Antarctic vortices are destroyed, Fresh air(containing new ozone) rushes into the area and the hole disappears.

In 1987, the international Conference, focused on the threat to the ozone layer, and industrialized countries agreed to reduce and eventually stop production chlorinated and fluorinated hydrocarbons (chlorofluorocarbons, CFCs) - chemicals that destroy the ozone layer. By 1992, the replacement of these substances with safe ones was so successful that a decision was made to completely destroy them by 1996. Today, scientists believe that in about fifty years the ozone layer will be completely restored.

It's no secret that our planet Earth is unique in solar system, since it is the only planet on which life exists. And the origin of life on Earth was possible thanks to a special protective ball of ozone, which covers our planet at an altitude of 20-50 km. What is ozone and why is it needed? The word “ozone” itself is translated from Greek as “smelling”, because it is its smell that we can feel after. Ozone is a blue gas consisting of triatomic molecules, essentially even more concentrated oxygen. The importance of ozone is enormous, since it is what protects the Earth from the harmful effects of ultraviolet rays coming from the Sun. Unfortunately, we people do not appreciate what was created by nature (or God) over billions of years, and one of the results of destructive human activity was the appearance of ozone holes, which we will talk about in today’s article.

What are ozone holes?

First, let’s define the very concept of an “ozone hole” and what it is. The fact is that many people mistakenly imagine the ozone hole as some kind of hole in the atmosphere of our planet, a place in which the ozone sphere is completely absent. In fact, this is not entirely true, it’s not that it is completely absent, it’s just that the concentration of ozone at the site of the ozone hole is several times lower than it should be. As a result, it is easier for ultraviolet rays to reach the surface of the planet and exert their destructive effect precisely in the areas of ozone holes.

Where are the ozone holes?

Well, in this case, the natural question will be about the location of the ozone holes. The first ozone hole in history was discovered in 1985 over Antarctica; according to scientists, the diameter of this ozone hole was 1000 km. Moreover, this ozone hole has a very strange behavior: it appears every time in August and disappears by the beginning of winter, only to appear again in August.

A little later, another ozone hole, albeit of a smaller size, was discovered over the Arctic. Nowadays, many small ozone holes have been discovered in different places, but the ozone hole over Antarctica ranks first in size.

Photo of the ozone hole over Antarctica.

How do ozone holes form?

The fact is that at the poles, due to the low temperature there, stratospheric clouds are formed containing ice crystals. When these clouds come into contact with molecular chlorine entering the atmosphere, a whole series of chlorine events occurs, the result of which is the destruction of ozone molecules, reducing its amount in the atmosphere. And as a result, an ozone hole is formed.

Causes of ozone holes

What are the causes of ozone holes? There are several reasons for this phenomenon, and the most important of them is pollution. environment. Many factories, factories, flue gas power plants emit into the atmosphere, including the ill-fated chlorine, and it, already entering into chemical reactions, makes a boom in the atmosphere.

Also, the appearance of ozone holes was greatly facilitated by nuclear tests conducted in the last century. At nuclear explosions Nitrogen oxides enter the atmosphere, which, entering into chemical reactions with ozone, also destroy it.

Airplanes flying in clouds also contribute to the appearance of ozone holes, since each of their flights is accompanied by the release of the same nitrogen oxide into the atmosphere, which is destructive to our protective ozone ball.

Consequences of ozone holes

The consequences of the expansion of ozone holes, of course, are not the most rosy - due to increased ultraviolet radiation, the number of people with skin cancer may increase. In addition, a person’s general immunity decreases, which leads to many other diseases. However, not only people, but also, for example, residents can suffer from increased ultraviolet radiation passing through the ozone hole upper layers ocean: shrimp, crabs, algae. Why are ozone holes dangerous for them? All the same problems with immunity.

How to deal with ozone holes

Scientists have proposed the following solution to the problem of ozone holes:

Begin regulating ozone-depleting emissions chemical elements in atmosphere.
Start to restore individually the amount of ozone at the site of ozone holes. Do it this way, using aircraft at an altitude of 12-30 km, spray piece ozone into the atmosphere. The disadvantage of this method is the need for significant economic costs, and a significant amount of ozone must be sprayed into the atmosphere at a time at modern technologies, alas, impossible.

Ozone holes, video

And finally interesting documentary about ozone holes.

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

For a long time, high-altitude aircraft and spacecraft flights were considered to be the culprits for the appearance of ozone holes in the Earth’s atmosphere.

However, numerous studies and experiments have shown that ozone levels can vary qualitatively due to certain natural pollutants air environment containing nitrogen.

The main causes of ozone holes

It has long been established that the bulk of natural ozone is found at an altitude of 15 to 50 kilometers above the Earth’s surface - in the stratosphere. Greatest benefit ozone brings by absorbing significant amounts of ultraviolet radiation from the sun, which would otherwise be destructive to living organisms on our planet. A decrease in ozone concentration in a certain location may be due to two types of air pollution. These include:

Natural processes that cause air pollution.
Anthropogenic pollution of the Earth's atmosphere.

In the Earth's mantle, degassing processes are constantly taking place, as a result of which a variety of organic compounds. Mud volcanoes and hydrothermal vents can generate these types of gases.

In addition, in the earth's crust there are certain gases that 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, the ground air over oil and gas basins often contains increased level methane These types of pollution can be classified as 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 a variety of chemical compounds are released into the atmosphere during the extraction and processing of numerous minerals from the bowels of the earth.

Large industrial cities, which are unique anthropogenic sources, also play a significant role in air pollution. Air masses in such areas are polluted through extensive flow 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. Appearing annually in August, this ozone hole disappeared between December and January.

The year 1992 was marked for scientists by the fact that another ozone hole, with a much smaller diameter, had formed over the Northern Hemisphere in Antarctica. 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 really dangerous phenomenon for living organisms. A decrease in the ozone layer significantly increases the flow of solar radiation, which can influence the sharp increase in the number of cancers. skin diseases. The appearance of ozone holes is no less destructive 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 came 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 air pollutants pledged to limit their release, and by 2000, to stop them 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, at Moscow State University, NPO Typhoon published a scientific work in which, according to calculations by geophysicists A.P. Kapitsa and A.A. Gavrilova, 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 RAS) b A.A. Gavrilov (Moscow State University). These two scientists were able 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 are abnormally low general content ozone in Antarctica in 1957-1959 are correct, it became obvious that the cause of ozone holes is different from anthropogenic.

The results of the research by Kapitsa and Gavrilov were published in Reports of the Academy of Sciences, 1999, volume 366, no. 4, p. 543-546