the new era of active space exploration, namelyspace rocket launches . The substances that make up the expiring jet stream (which propels the rocket) intensively destroy ozone. Thus, at the launch site of the launch vehicle, a large “hole” appears in the ozone layer, which, as it turns out, takes a very long time to heal. And every year there are more and more such “holes drilled in the atmosphere”. Which inevitably leads to the depletion of the Earth's ozone layer.
The second reason for the destruction of the Earth's ozone layer is
intensive development of high-altitude aviation(aircraft flying at altitudes above 12 km). The combustion products of these cars also destroy ozone molecules, leading to the depletion of the Earth's ozone layer. Ozone-active components of exhaust gases are nitrogen oxides and, to a lesser extent, carbon monoxide. Scientists have analyzed ways to reduce nitrogen oxide in jet fuel combustion products. However, to date, research results are disappointing. Reducing nitrogen oxide, which destroys stratospheric ozone, is impossible either by modernizing existing engines or by switching to “environmentally friendly” fuels (liquefied natural gas and liquefied or compressed hydrogen). Reducing the emission of substances that destroy the Earth's ozone layer will be possible only with the creation of fundamentally new engines. But this is still a long way off...
The third reason for the destruction of the Earth's ozone layer is
use of nitrogen fertilizers in agriculture. As they decompose, they release nitrogen oxides, which rise into the stratosphere and... destroy ozone molecules, causing the depletion of the Earth's ozone layer, of course.
The fourth reason for the destruction of the Earth's ozone layer is
widespread use of freons in human economic activity(as sprayers, in the refrigeration industry). At the surface of the earth, these gases are practically harmless, since they do not enter into any chemical reactions. But, once in the stratosphere, freons, under the influence of solar radiation, enter into photochemical reactions, releasing atomic chlorine. And one chlorine atom, as mentioned above, during its long life is capable of destroying up to one hundred thousand ozone molecules. Here's one warrior in the field. And the amount of freons in the atmosphere is growing year by year, increasing by about 8-9% annually.
We looked at the reasons for the destruction of the Earth's ozone layer. To sum it up sadly: human activity is destroying the planet. It's time to move on to the next point of this article. What threatens us with the depletion of the Earth's ozone layer?
Consequences of destruction and depletion of the Earth's ozone layer.
Depletion of the ozone layer increases the flow of solar radiation to Earth.
According to doctors, every percentage of ozone lost on a planetary scale causes:
up to 150 thousand additional cases of blindness due to cataracts,
the number of skin cancers increases by 2.6 percent,
The number of diseases caused by a weakened human immune system is significantly increasing.
But it's not just people who suffer. Ultraviolet radiation is also extremely harmful to plankton, fry, shrimp, crabs, algae living on the surface of the ocean, and other organisms of the biosphere.
The problem of ozone layer depletion was discovered a long time ago, but by the 1980s, scientists sounded the alarm. If ozone is significantly reduced in the atmosphere, the earth will lose its normal temperature regime and stop cooling. As a result, a huge number of documents and agreements were signed in various countries to reduce the production of freons. In addition, a replacement for freons was invented - propane-butane. According to its technical parameters, this substance has high performance and can be used where freons are used.
Today, the problem of ozone layer destruction is very relevant. Despite this, the use of technologies using freons continues. At the moment, people are thinking about how to reduce the amount of freon emissions and are looking for substitutes to preserve and restore the ozone layer.
20. Acid rain: causes, mechanisms of occurrence, impact on flora and fauna, buildings.
Acid rain is usually called any precipitation (rain, snow, hail) containing any amount of acid. The presence of acids leads to a decrease in pH levels. Hydrogen index (pH) is a value that reflects the concentration of hydrogen ions in solutions. The lower the pH level, the more hydrogen ions in the solution, the more acidic the environment.
For rainwater, the average pH value is 5.6. When the pH of precipitation is less than 5.6, it is referred to as acid rain. Compounds that lead to a decrease in the pH level of sediments are oxides of sulfur, nitrogen, hydrogen chloride and volatile organic compounds (VOCs).
Causes of acid rain
Acid rain By the nature of their origin, there are two types: natural (arising as a result of the activity of nature itself) and anthropogenic (caused by human activity).
Natural acid rain
There are few natural causes of acid rain:
microorganism activity, volcanic activity, lightning discharges, combustion of wood and other biomass.
Anthropogenic acid rain
The main cause of acid rain is air pollution. If about thirty years ago industrial enterprises and thermal power plants were named as global causes causing the appearance of compounds in the atmosphere that “oxidize” rain, today this list has been supplemented by road transport.
Thermal power plants and metallurgical enterprises “donate” about 255 million tons of sulfur and nitrogen oxides to nature.
Solid fuel rockets have also made and are making a significant contribution: the launch of one Shuttle complex results in the release of more than 200 tons of hydrogen chloride and about 90 tons of nitrogen oxides into the atmosphere.
Anthropogenic sources of sulfur oxides are enterprises producing sulfuric acid and refining oil.
Exhaust gases from motor vehicles account for 40% of nitrogen oxides entering the atmosphere.
The main source of VOCs in the atmosphere, of course, are chemical industries, oil storage facilities, gas stations and gas stations, as well as various solvents used both in industry and in everyday life.
The final result is as follows: human activity supplies the atmosphere with more than 60% of sulfur compounds, about 40-50% of nitrogen compounds and 100% of volatile organic compounds.
Oxides entering the atmosphere react with water molecules, forming acids. Sulfur oxides, when released into the air, form sulfuric acid, and nitrogen oxides form nitric acid. One should also take into account the fact that the atmosphere above large cities always contains particles of iron and manganese, which act as catalysts for reactions. Since there is a water cycle in nature, water in the form of precipitation sooner or later falls on the earth. Acid also gets in with the water.
Consequences of acid rain
Oxidation of water resources. Rivers and lakes are the most sensitive. Fish die. Despite the fact that some species of fish can withstand slight acidification of water, they also die due to the loss of food resources. In those lakes where the pH level was less than 5.1, not a single fish was caught. This is explained not only by the fact that adult fish die - at a pH of 5.0, most cannot hatch fry from the eggs, which results in a reduction in the numerical and species composition of fish populations.
Harmful effects on vegetation. Acid rain affects vegetation directly and indirectly. The direct impact occurs in high mountain areas, where tree crowns are literally immersed in acidic clouds. Excessively acidic water destroys leaves and weakens plants. Indirect impact occurs due to a decrease in the level of nutrients in the soil and, as a consequence, an increase in the proportion of toxic substances.
Destruction of human creations. Building facades, cultural and architectural monuments, pipelines, cars - everything is exposed to acid rain. Many studies have been conducted, and they all say one thing: acid rain exposure has increased significantly over the past three decades. As a result, not only marble sculptures and stained glass windows of ancient buildings are under threat, but also leather and paper products of historical value.
Human health. Acid rain itself does not have a direct impact on human health - if you get caught in such rain or swim in a reservoir with acidified water, you do not risk anything. Compounds that form in the atmosphere due to the ingress of sulfur and nitrogen oxides into the atmosphere pose a threat to health. The resulting sulfates are transported by air currents over considerable distances, are inhaled by many people, and, as studies show, provoke the development of bronchitis and asthma. Another point is that a person eats the gifts of nature; not all suppliers can guarantee the normal composition of food products.
21. Smog: types, mechanism of formation
Smog is a mixture of smoke, fog and some pollutants.
The earth is designed in such a way that its unique ecosystem is preserved. These purposes are served by layers of the atmosphere that cover the planet from the penetration of ultraviolet rays, radiation, and space debris. In nature, everything is perfect, and interference with its structure leads to various cataclysms and disruption of the established order. At the end of the 20th century, a clear problem emerged that affects all of humanity. An ozone hole formed in the Antarctic region and attracted the attention of scientists from all over the world. The critical situation of the environment has been aggravated by another serious problem.
It was found that a gap more than a thousand kilometers in size had formed in the ozone layer surrounding the earth's surface. Radiation enters through it, adversely affecting people, animals and vegetation. Ozone holes and 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 that is exposed to ultraviolet rays. Thanks to this reaction, the planet becomes shrouded in a layer of gas through which radiation cannot penetrate. This layer is located at an altitude of 25-50 kilometers above the surface. The thickness of ozone is not very large, but it is quite enough for all living things to exist on the planet.
What the ozone hole is was learned in the 80s of the last century. This sensational discovery was made by English scientists. In places where ozone is destroyed, the gas is not completely absent; its concentration decreases to a critical level of 30%. The gap formed in the stratosphere layer allows ultraviolet rays to pass to the ground, capable of burning 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 became denser and practically closed the hole in the stratospheric layer. Critical altitude points are located at a distance of 19 kilometers from the ground.
The second ozone hole has appeared over the Arctic. Its dimensions were much smaller, but otherwise there was a striking similarity. The critical heights and disappearance times coincided. Currently, ozone holes are appearing in different places.
How does the ozone layer thin out?
Scientists attribute the problem with the thinning of the ozone layer to natural phenomena occurring at the poles of 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 this gas that destroys the gas that is so necessary to protect the planet.
The earth went through a period of volcanic activity. This also had a detrimental effect on the thickness of the ozone layer. Emissions of combustion products into the atmosphere 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. Due to air currents, the gas rises and fills the resulting void. This theory proves that the circulation of ozone 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 that harm ozone. The gas is also destroyed by exposure to hydrogen, bromine and oxygen. The reasons for the appearance of these compounds in the air lie in human activities on the planet. The prerequisites are:
- functioning of plants and factories;
- lack of treatment facilities;
- atmospheric emissions from thermal power plants;
Nuclear explosions had a detrimental effect on the integrity of the atmosphere. Their consequences still affect the ecology of the planet. At the moment of the explosion, a huge amount of nitrogen oxides are formed, which, rising, destroy the gas that protects the earth from radiation. Over 20 years of testing, more than three million tons of this substance were released into the atmosphere.
Jet airplanes have a devastating effect on the ozone layer. When fuel burns in turbines, nitrogen oxides are released, they directly enter the atmosphere and destroy gas molecules. Currently, out of a million tons of emissions of this substance, a third comes from airplanes.
It would seem that mineral fertilizers are harmless and useful, but in fact they also have a detrimental effect on the atmosphere. When interacting with bacteria, they are processed into nitrous oxide, and then, under the influence of chemical reactions, they change their shape and become oxides.
Thus, the ozone hole is a product not only of natural phenomena, but also of human impact on the environment. Rash 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 humans thrive thanks to its life-giving rays. This was noted by the people of the ancient world, who considered the Sun God to be the main idol. But the star can also become the cause of the death of life on the planet.
Through the ozone holes formed under the influence of the tandem of man and nature, solar radiation can reach the earth and incinerate everything that was once nurtured. The harmful consequences for 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, people's skin will suffer, and then other organs.
The consequences of the formation of ozone holes affect not only humanity. Vegetation suffers, as well as fauna and inhabitants of the deep sea. Their mass extinction is a direct consequence of processes occurring in 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 boil 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, radically new scientific developments are needed that will make it possible to produce, fuel, produce and fly without the use of nitrogen, fluorine and bromine, as well as their derivatives.
The problem is associated with inefficient production and agricultural activities. It's time to think:
- on the installation of treatment facilities on smoking pipes;
- on replacing chemical fertilizers with organic ones;
- about the transition of transport to electricity.
Over the past sixteen years, since 2000, quite a lot has been done. Scientists have achieved amazing results: the size of the ozone hole over Antarctica has decreased by an area equal to the territory of India.
The consequences of careless and inattentive attitude towards the environment are already making themselves felt. In order not to aggravate the situation to an even greater extent, it is necessary to address the problem at the global level.
Recently, newspapers and magazines have been full of articles about the role of the ozone layer, in which people are intimidated by possible problems in the future. You can hear from scientists about upcoming climate changes, which will negatively affect all life on Earth. Will a potential danger far removed from humans really turn into such horrific events for all earthlings? What consequences does humanity expect from the destruction of the ozone layer?
The formation process and significance of the ozone layer
Ozone is a derivative of oxygen. While in the stratosphere, oxygen molecules are chemically exposed to ultraviolet radiation, after which they break down into free atoms, which, in turn, have the ability to combine with other molecules. With this interaction of oxygen molecules and atoms with third bodies, a new substance arises - this is how ozone is formed.
Being in the stratosphere, it affects the thermal regime of the Earth and the health of its population. As a planetary “guardian,” ozone absorbs excess ultraviolet radiation. However, when it enters the lower atmosphere in large quantities, it becomes quite dangerous for the human species.
An unfortunate discovery by scientists - an ozone hole over Antarctica
The process of ozone layer depletion has been the subject of much debate among scientists around the world since the late 60s. In those years, environmentalists began to raise the problem of emissions of combustion products into the atmosphere in the form of water vapor and nitrogen oxides, which were produced by jet engines of rockets and airliners. The concern has been that nitrogen oxide emitted by aircraft at 25 kilometers altitude, which is where the Earth's shield forms, can destroy ozone. In 1985, the British Antarctic Survey recorded a 40% decrease in the concentration of ozone in the atmosphere above their Hally Bay base.
After the British scientists, many other researchers illuminated this problem. They managed to outline an area with low ozone levels already outside the southern continent. Because of this, the problem of ozone hole formation began to arise. Soon after this, another ozone hole was discovered, this time in the Arctic. However, it was smaller in size, with ozone leakage up to 9%.
Based on the results of the research, scientists calculated that in 1979-1990 the concentration of this gas in the earth’s atmosphere decreased by about 5%.
Depletion of the ozone layer: the appearance of ozone holes
The thickness of the ozone layer can be 3-4mm, its maximum values are located at the poles, and its minimums are located along the equator. The highest concentration of gas can be found 25 kilometers in the stratosphere above the Arctic. Dense layers are sometimes found at altitudes up to 70 km, usually in the tropics. The troposphere does not have much ozone because it is highly susceptible to seasonal changes and various types of pollution.
As soon as the gas concentration decreases by one percent, there is an immediate increase in the intensity of ultraviolet radiation above the earth's surface by 2%. The influence of ultraviolet rays on planetary organics is compared to ionizing radiation.
Depletion of the ozone layer could cause disasters associated with excessive heating, increased wind speeds and air circulation, which could lead to new desert areas and reduce agricultural yields.
Meeting ozone in everyday life
Sometimes after rain, especially in the summer, the air becomes unusually fresh and pleasant, and people say that it “smells like ozone.” This is not a figurative formulation at all. In fact, some part of the ozone reaches the lower layers of the atmosphere with air currents. This type of gas is considered the so-called beneficial ozone, which brings a feeling of extraordinary freshness to the atmosphere. Mostly such phenomena are observed after thunderstorms.
However, there is also a very harmful type of ozone that is extremely dangerous for people. It is produced by exhaust gases and industrial emissions, and when exposed to the sun's rays, it enters into a photochemical reaction. As a result, the formation of so-called ground-level ozone occurs, which is extremely harmful to human health.
Substances that destroy the ozone layer: the effect of freons
Scientists have proven that freons, which are used en masse to charge refrigerators and air conditioners, as well as numerous aerosol cans, cause the destruction of the ozone layer. Thus, it turns out that almost every person has a hand in the destruction of the ozone layer.
The causes of ozone holes are that freon molecules react with ozone molecules. Solar radiation causes freons to release chlorine. As a result, ozone splits, resulting in the formation of atomic and ordinary oxygen. In places where such interactions occur, the problem of ozone depletion occurs and ozone holes occur.
Of course, the greatest harm to the ozone layer is caused by industrial emissions, but the household use of preparations that contain freon, one way or another, also has an impact on the destruction of ozone.
Protecting the ozone layer
After scientists documented that the ozone layer is still being destroyed and ozone holes appear, politicians began to think about preserving it. Consultations and meetings have been held around the world on these issues. Representatives of all states with well-developed industry took part in them.
Thus, in 1985, the Convention for the Protection of the Ozone Layer was adopted. Representatives from forty-four conference participating states signed this document. A year later, another important document was signed, called the Montreal Protocol. In accordance with its provisions, there should have been a significant restriction of the global production and consumption of substances that lead to the destruction of the ozone layer.
However, some states were unwilling to submit to such restrictions. Then, specific quotas for dangerous emissions into the atmosphere were determined for each state.
Protection of the ozone layer in Russia
In accordance with current Russian legislation, the legal protection of the ozone layer is one of the most important and priority areas. Legislation related to environmental protection regulates a list of protective measures aimed at protecting this natural object from various types of damage, pollution, destruction and depletion. Thus, Article 56 of the Legislation describes some activities related to the protection of the planet’s ozone layer:
- Organizations for monitoring the effect of the ozone hole;
- Continued control over climate change;
- Strict compliance with the regulatory framework on harmful emissions into the atmosphere;
- Regulating the production of chemical compounds that destroy the ozone layer;
- Application of penalties and punishments for violation of the law.
Possible solutions and first results
You should know that ozone holes are not a permanent phenomenon. With a reduction in the amount of harmful emissions into the atmosphere, a gradual tightening of ozone holes begins - ozone molecules from neighboring areas are activated. However, at the same time, another risk factor arises - neighboring areas are deprived of a significant amount of ozone, the layers become thinner.
Scientists around the world continue to engage in research and are intimidated by bleak conclusions. They calculated that if the presence of ozone decreased by just 1% in the upper atmosphere, there would be an increase in skin cancer of up to 3-6%. Moreover, a large amount of ultraviolet rays will negatively affect people's immune system. They will become more vulnerable to a wide variety of infections.
It is possible that this may actually explain the fact that in the 21st century the number of malignant tumors is increasing. Increasing levels of ultraviolet radiation also negatively affect nature. The destruction of cells in plants occurs, the process of mutation begins, as a result of which less oxygen is produced.
Will humanity cope with the challenges ahead?
According to the latest statistics, humanity is facing a global catastrophe. However, science also has optimistic reports. After the adoption of the Convention for the Protection of the Ozone Layer, all of humanity became involved in the problem of preserving the ozone layer. Following the development of a number of prohibitive and protective measures, the situation was slightly stabilized. Thus, some researchers argue that if all of humanity engages in industrial production within reasonable limits, the problem of ozone holes can be successfully solved.
If you have any questions, leave them in the comments below the article. We or our visitors will be happy to answer them
Nature is a state of balance. The anthropogenic factor disrupts the cycle of substances, which affects the planet. One example is the ozone layer. Humanity constantly destroys it with flights into space, while the substance is additionally subjected to decay in the lower layers of the atmosphere due to freons and emissions from light industry. This poses a list of problems:
- amplification of radiation rays;
- deterioration of air frequency parameters;
- changes in soil characteristics;
- acid rain;
- toxic mists.
Together, these factors threaten to destroy the Earth's ecology.
The ozone layer is located between 15 and 40 km in the atmosphere. Despite the variation in heights, the thickness of the shell is measured in several millimeters. The thickest layer is above the poles. Lowest concentration at the equator. The ozone layer blocks the lion's share of ultraviolet radiation. On average, the shell reduces the amount of ultraviolet radiation by 6.5 thousand times.
Ozone formation
Under the influence of sunlight, the ozone molecule breaks down into an oxygen molecule and an atom, thus absorbing dangerous radiation. In the presence of a third oxygen atom, these particles combine again to form an ozone molecule. The process is endless, but can be disrupted by humans.
Causes of ozone layer depletion
The first conversations about the destruction of the ozone layer began in the 1960s. The reason was a decrease in ozone concentration by 40 percent over one of the British Arctic stations. At the same time, research began into the reasons why this destruction became possible at all.
Air transportation. Airplanes in the skies became the norm a long time ago, but it so happens that it is they who violate the ozone layer during their flight. No, cars do not punch “ozone holes” with their cabins, but aircraft fuel (aviation gasoline and kerosene) form CO 2 from ozone during combustion. Under Earth's surface conditions, carbon dioxide is formed as a result of fuel combustion in an oxygen environment. At an altitude of several tens of kilometers, the air is thinner. Along with oxygen, ozone also participates in the combustion process.
Carbon leads to disruption of the ultraviolet conversion chain by ozone. Sunlight is replaced by a carbon atom. The resulting CO 2 sinks to the surface of the Earth, and the concentration of the forming substance in the ozone layer decreases. In the 60s, when flights were not yet so accessible, this problem could still be solved by itself. But today the average person flies several times a year, and for a large businessman or politician the norm is to make several flights in a week. It is simply impossible to refuse such a convenient means of transportation.
Cosmetics industry. How often does each person use deodorant, hairspray or air freshener? These things are the key to human comfort.
Moreover, they contain the same chlorofluorocarbons that destroy the ozone layer. Fortunately, this particular issue was one of the first to be closed. Back in the 1970s, at a Montreal conference, it was decided to find a replacement for chlorofluorocarbons (CFCs). Propane-butylene was used, which was no different in quality from CFCs.
Forest fires. The formed methyl chloride (CH 3 Cl) with rising currents of heated air during large-scale fires is capable of reaching the upper part of the troposphere and reacting with ozone.
Refrigeration units. The basis of any refrigeration equipment is freon, which is used as a refrigerant.
Freon is any substance with a low boiling point. After all, what is cold? This is the absence of heat. The refrigerant takes up heat, boils, enters the compressor, where it is compressed until the boiling point rises so much that the gas turns into a liquid again. The gas becomes a liquid, releasing heat into the atmosphere, and the refrigerant is put back into service. It is precisely in this moment that lies the basis for understanding the impact of freons on the atmosphere and the ozone layer. Freon operates in a closed system, its leaks are insignificant. Freon can enter the atmosphere in three cases:
- improper disposal;
- violation of operation;
- poor quality assembly.
Today, the use of “R 12” freon, which has a particularly destructive effect on the ozone layer, is prohibited. But you can go the other way and introduce international quality control of the assembly and operation of refrigeration equipment, and monitor proper disposal. After all, it’s easier not to throw it away than not to use it.
How do freons affect the ozone layer?
They decompose in the upper layers of the atmosphere and the decomposition product is atomic chlorine, which leads to disruption of the chain of conversion of ultraviolet rays by ozone.
Ozone does not decompose into an oxygen molecule and atom, suitable for further reaction, but into chlorine oxide and oxygen. After this, in chlorine oxide, free oxygen atoms, of which there are sufficient quantities floating around, replace chlorine. As a result, after the reaction, two oxygen molecules and a chlorine atom are formed, which continues to destroy ozone over and over again. One atom can destroy about 100 thousand ozone molecules.
Chlorine cycle of ozone destruction.
Cl + O 3 → ClO + O 2
O + ClO → Cl + O 2
An ordinary chemical reaction consumes huge quantities of a substance that is invaluable in the stratosphere.
Consequences of destruction, ozone holes
The result of the destruction of the ozone layer is the so-called ozone hole. This is not literally a hole in the shell - just a place where the ozone concentration is greatly reduced. The worst thing is that such phenomena are wandering and the mechanism of their occurrence is unclear.
An ozone hole regularly appears over Australia in the summer, which is accompanied by outbreaks of cancer. But cancer is not the whole list of negative effects:
- Due to the increase in the amount of sunlight, burns will begin to occur on the leaves of plants and trees; the vegetation will no longer be able to compensate for the intake of CO 2. This is significant.
- The upper layers of the soil will begin to dry out, which means that farming, which is humanity’s main means of subsistence, will become impossible under the new conditions.
- The radiation background of the planet will increase significantly, which means the risk of getting radiation sickness will increase significantly.
Taken together, all these factors can destroy not only humanity, but the Earth as a whole.
Acid rain
Acid rain produces roughly the same greenhouse gas emissions that contribute to the development of ozone holes.
Chlorofluorocarbons, when decomposed, leave carbon, which combines with water to form carbonic acid, although this has only a small effect on the formation of acid rain. Nitrogen and sulfur emissions play a major role. They are formed as a result of fuel combustion. Sulfur is present as a pollutant in approximately 70 percent of the fuels, coal and oil burned on the planet. Nitrogen and sulfur, combining with oxygen in the atmosphere, first form oxides, and then combining with water, acids, which precipitate in the form of rain.
How does this threaten humanity? Changes in living conditions. Balance is also necessary in the surrounding substances. All of nature is designed to exist in a neutral environment, and an increase in the acidity of rainwater will lead to a change in the composition of the soil, and therefore a change in the entire biological community of the Earth. Specifically for humans, this means a change in farming conditions. All centuries of work on developing crop rotation methods will go to waste, and we will again return to the slash-and-burn method. And this is with a positive development of events, since acid rain burns leaves that are not accustomed to it, and it is unknown how many more liters of poisoned water this or that plant will endure.
The human immune system is also not happy with this change in the composition of the rain. In Russia alone, due to such precipitation, the number of people suffering from asthma has almost doubled. And this is a new growth of industry, only associated with medicines.
Toxic mists
Another result of constant air pollution is toxic fog or smog. First appearing in London in the 20th century, smog contained large amounts of suspended particles of coal, soot and sulfur. Over the past 5 days, the number of deaths from cardiovascular and respiratory diseases has increased significantly. It should be noted that the composition of contaminants has become much more sophisticated.
Today, smog can be seen in New York, London, Osaka or Beijing. This phenomenon occurs as a consequence of a large number of factories concentrated in one place. What does this mean? Violation of metabolic processes in the body. Unfortunately, cancer, respiratory and cardiovascular diseases are only part of the picture.
In China, as a result of industrialization in a relatively short time, smog has become quite common. In general, a fog of emissions lingers over Beijing every summer, which is accompanied by deteriorating water quality. All this has led to an increase in the popularity of the caesarean section procedure. Due to metabolic disorders in the body, women in the central part of the country are forced to carry a child for up to 12 months while waiting for a natural birth.
The Chinese government is fighting for the cleanliness of the city; many factories have left the capital, but it is unclear when this will affect the environmental situation.
Earth is the only planet in the solar system that has life. The existence of living organisms is possible because the planet is protected from deadly solar radiation by the ozone layer, located in the stratosphere (10 - 50 km from the planetary surface). Ozone is a bluish gas whose molecule consists of three oxygen atoms. Its name translated from Greek means “smelling”. Indeed, after taking a deep breath of air, you can feel how the gas smells.
Without the ozone layer, the planet will literally burn up under the ultraviolet influence of the Sun. However, humanity has never learned to be grateful for the opportunity to live on Earth. Ozone holes have always existed on the planet. They appear and disappear for natural reasons. However, as a result of anthropogenic activities, there is a dangerous expansion of areas of the atmosphere unprotected by ozone, due to which the Earth is becoming increasingly exposed to ultraviolet radiation.
What are ozone holes?
Do not think that the ozone hole is a space in the atmosphere completely devoid of protective gas. In fact, ozone is present in this area, but in lower concentrations. Through such a section of the atmosphere, it is easier for ultraviolet radiation to reach the earth's surface. Within the ozone hole, blue gas concentrations can be as low as 30% of normal.
Ozone hole over Antarctica
The first and largest ozone hole, reaching 1000 km in diameter, was discovered in 1985 over Antarctica. The gas concentration in this space was 50% below normal, and the greatest depletion of the ozone layer was observed at a distance of 15–20 km from the planetary surface.
The hole over the southern polar region is characterized by seasonal appearance and disappearance. A significant decrease in gas concentration is observed at the end of winter and early spring (in the southern hemisphere this is August and September). This phenomenon is due to the peculiarities of the subpolar climate.
During the Antarctic winter, a vortex is formed due to a decrease in air temperature. The air mass within the vortex circulates around the south pole. Mixing with air masses of other latitudes is weak or absent altogether. During the polar winter, the planetary surface is deprived of sunlight, and ozone formation is stopped. And the gas accumulated in the summer is gradually destroyed, since the molecules of the substance are not stable. When the polar night ends and the Antarctic summer returns, the ozone concentration begins to slowly increase and reaches its maximum value by the end of summer.
View from space
A similar seasonal hole, but not as large, is located over the Arctic Ocean. Smaller formations are being identified by researchers around the globe.
Causes of ozone layer depletion
The reasons for the depletion of the ozone layer are two types of factors:
- natural (natural processes causing air pollution);
- anthropogenic (caused by human influence).
The natural cause of the emergence of areas with low ozone concentrations is processes occurring in the circumpolar regions of the planet. According to scientific theory, during polar nights, when no ozone is produced in the atmosphere due to the lack of solar radiation, chlorine clouds form. Chlorine, which forms the basis of cloud mass, has a destructive effect on the ozone remaining in the stratosphere.
The resulting hole is closed as soon as the polar day arrives, the solar ultraviolet interacts with oxygen molecules. The resulting blue gas, which is a concentrated version of oxygen, rises into the stratosphere. This theory shows that the thinning and renewal of the ozone layer is a continuous natural process that has always existed.
It also affects the formation of ozone holes in the atmosphere. When volcanoes explode, combustion products are released into the air, which have a destructive effect on ozone molecules.
However, in recent decades, the destruction of the ozone layer has become alarming due to anthropogenic impact. Ozone is an unstable gas. It is destroyed due to increased emissions of chlorine, bromine, hydrogen, freons and other chemical compounds entering the atmosphere as a result of human activity, creating the greenhouse effect.
The main sources of atmospheric pollution:
- plants and factories that are not equipped or insufficiently equipped with treatment plants;
- mineral fertilizers applied to cultivated lands;
- jet planes;
- nuclear explosions.
When jet aircraft fly, nitrogen oxides are released into the air as a result of fuel combustion in turbines. Once in the stratosphere, they destroy blue gas molecules. Today, 1/3 of nitrogen oxide emissions comes from air transport.
Nuclear testing was banned by the UN in 1996, but the environmental problems it caused still exist. During a nuclear explosion, a gigantic amount of nitrogen oxides was formed, destroying the ozone layer. Over the 20 years during which nuclear tests were carried out, more than 3 million tons of nitrogen compounds spread into the atmosphere.
Mineral fertilizers, getting into the soil and interacting with soil microorganisms, are also converted into nitrogen oxides through complex chemical reactions.
Consequences of ozone holes
A decrease in the ozone layer leads to increased exposure to solar radiation on the planet's surface. Solar radiation without an ozone shield poses a mortal danger to living organisms.
The main consequence of the destruction of the Earth's ozone layer will be the extinction of all representatives of the animal and plant world. Already today, scientists are noticing the massive death of marine planktonic species and deep-sea inhabitants due to the increased negative effects of ultraviolet radiation.
As for the impact on humans, an increase in solar radiation negatively affects the condition of the skin and causes an increase in cases of melanoma - skin cancer. If the amount of ultraviolet radiation reaching the Earth increases, the incidence of other oncological pathologies will also increase. So, if the level of blue gas in the stratosphere decreases by another 1%, then the number of cancer patients will increase by 7 thousand per year.
Ways to solve the problem
Since the main culprit in the destruction of the planet’s ozone layer is human activity, normalizing the state of the atmosphere requires the creation of new production and operation technologies aimed at significantly reducing and even eliminating emissions of freons and other harmful compounds.
To prevent the appearance of ozone holes, you need:
- improvement of cleaning structures on factory pipes;
- reducing the use of mineral fertilizers;
- the creation of vehicles that run not on combustible fuel, but on electricity and other energy sources.
Such preventive measures have a positive effect, but, according to environmentalists, measures to restore the ozone layer are much more effective. This refers to the spraying of artificially synthesized gas by special flying devices at an altitude of 10–30 km above the earth’s surface. This method will allow you to quickly patch up holes in the atmosphere, but it is not without its drawbacks. The first problem is the high cost of the event (it is economically feasible only with the joint participation of several states). The second problem is that delivering synthetic ozone to the spray site is difficult and dangerous for the carrier.
In 1985, the Vienna Convection on the protection of the ozone layer was adopted. In 1987, the Montreal Protocol was created, which lists the most harmful volatile substances that appear in the airspace as a result of human activity. Participating countries have pledged to reduce emissions of these substances and eliminate them by the beginning of the 21st century.
The results of the international agreement are visible. The area of ozone holes has decreased in different parts of the planet, including over Antarctica. The world community continues to seriously struggle with the problem: environmentally friendly vehicles are being created, industrial and agricultural production technologies are being improved.