“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 global ecological crisis, understood by the entire population of the planet. The real hope for its prevention lies in continuous environmental education and enlightenment of people.

It is possible to identify the main reasons leading to environmental disaster:

· 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 allotropic modification oxygen. The nature of the chemical bonds in ozone causes its instability (through certain time ozone spontaneously transforms into oxygen: 2O 3 → 3O 2) and high oxidizing capacity. The oxidative effect of ozone on organic substances is associated with the formation of radicals: RH + O 3 → RO 2. +OH.

These radicals initiate radical chain reactions with bioorganic molecules(lipids, proteins, nucleic acids), which leads to cell death. The use of ozone to sterilize drinking water is based on its ability to kill microbes. Ozone is not indifferent to higher organisms. Prolonged exposure to an environment containing ozone (for example, in physiotherapy rooms and quartz irradiation) can cause severe damage to the nervous system. Therefore, ozone in large doses is a toxic gas. The maximum permissible concentration in the air of the working area is 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 from the 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) at photochemical reactions with the participation of 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 most abundant, the main role in seasonal and longer-term changes in its concentration is played by air mass transfer processes.

The thickness of the ozone layer over Europe is decreasing at a rapid pace, which cannot but worry the minds of scientists. For last year The thickness of the ozone “coat” has been reduced by 30%, and the rate of deterioration of the natural protective shell has reached the highest level in the last 50 years. It has been established that chemical reactions that destroy ozone 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?

The thin ozone layer (2-3 mm when distributed around the globe) is unable to prevent the penetration of short-wavelength 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.

Associated with a decrease in the ozone layer climate change. It is clear that changes will occur not only in the territory over which it “stretches” ozone hole. 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 the spring, the ozone content over Antarctica can decrease by 70% relative to the annual average. The 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. The new era is marked by the emergence artificial satellites Earth, observing atmospheric ozone and providing 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 is called the "ozone hole" (although there is no hole in proper meaning this word, of course, did not exist).

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 anthropogenic pollution atmosphere, or is it 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 with ozone of some substances produced chemical plants. These are primarily chlorinated hydrocarbons and especially freons - chlorofluorocarbons, or hydrocarbons, in which all or most 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 dry cleaning agents, for extinguishing fires in transport, as foaming agents, and 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. Majority anthropogenic sources concentrated in cities that occupy only a small part of the territory of our planet. As a result of the movement of air masses on the leeward side of large 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. Basic products organic synthesis are ethylene (almost half of all organic matter), propylene, butadiene, benzene, toluene, xylenes and methanol. Emissions from chemical and petrochemical industry enterprises contain a wide range of pollutants: components of feedstock, intermediate, by-products and target synthesis products.

3) Aerosols. Chlorofluorocarbons (freons) are widely used as volatile components (propellants) in aerosol packages. For these purposes, about 85% of freons were used and only 15% in refrigeration 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 are deep faults and cracks reach the Earth's surface 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 in them 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 were found in air bubbles Antarctic ice 2000 years old. 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 .

It is sometimes argued that since freon molecules are much heavier than nitrogen and oxygen, they cannot reach the stratosphere at significant quantities. However, atmospheric gases are completely mixed, rather than 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. Therefore, even such heavy gases as inert gases or freons are evenly distributed in the atmosphere, including reaching the stratosphere. Experimental measurements their concentrations in the atmosphere confirm this. If the gases in the atmosphere did not mix, then such heavy gases from its composition as argon and 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.

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 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.

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.

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 characteristics 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.

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 concentration in different points planets. 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 Dasa, it is planned to raise balloons with infrared lasers, with the help of which ozone is obtained from diatomic oxygen. If this experiment turns out to be successful, in the future it is planned to use the experience of the Russian Mir orbital station and create several space platforms with energy sources and lasers at an altitude of 400 km. The laser beams will be directed towards central part ozone layer and will constantly feed 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 an International Committee to develop a strategy for the survival of humanity in extreme conditions.

References

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.

Instructions

To prevent new ozone holes from forming, find out why they appear. Ozone is the same oxygen, but having not two atoms, but three. Oxygen acquires a third atom at an altitude of 12 - 50 kilometers due to exposure to sunlight, due to which it is ionized. Ozone accumulates in the upper layers of the atmosphere and forms the ozone layer, which covers the entire planet and protects it from harmful effects ultraviolet rays of the sun.

Places where the ozone layer is noticeably thinner are called ozone holes. This layer has always become thinner, not only due to the harmful effects of human activity. The destruction of the ozone layer occurs due to chemical bonding with hydrogen, bromine, methane, chlorine, etc. As a result, it forms completely different chemical compounds, but after some time this modification of oxygen accumulates again.

Factories, factories, transport, and various household appliances increase the content in the atmosphere of substances that destroy the ozone layer, and its thinning occurs faster than restoration. The very first ozone hole appeared over Antarctica because the sun's rays needed to form ozone were insufficient there.

Now ozone holes have appeared over the Arctic, and the ozone layer in the atmosphere is decreasing. You can prevent new holes from forming by trying to use your car less. If the distance to your destination is short, walk. Do not spray air fresheners and all other sprays unless absolutely necessary; they also contain substances that destroy the ozone layer.

If you have a summer house or a private house, plant more trees and other plants; they produce the necessary oxygen. Convince your friends and family to follow these too simple rules Only together will humanity contribute to the restoration of the ozone layer.

Video on the topic

Sources:

• What are ozone holes? How to prevent their occurrence?

Ozone is a bluish gas made up of three oxygen atoms (O3). When the ozone layer thins, more ultraviolet radiation begins to penetrate to the Earth, which is necessary for the normal functioning of people. Ozone absorbs excess ultraviolet radiation, including that which is dangerous for all life on Earth. Ozone holes are not a hole in the atmosphere in the full sense. This is a slow steady decrease in the concentration of the stratospheric layer.

Instructions

Recently, extreme precipitation events have become more frequent, and they, in turn, cause natural disasters(floods, landslides). It has not yet been established who is responsible for the ozone holes. Maybe the cause of their occurrence is flights, the result of human activity or greenhouse gases, but one thing is clear - the ozone layer is becoming thinner, and this is already a comprehensive problem.

However, the anthropogenic factor is only one component of the problem. There is a possibility that the planet itself is destroying itself, displacing humanity with the help of radiation ( – cancer diseases). The fact is that the map of ozone holes coincides with the map of methane deposits, which is why we can say that holes have always been. If you want to help, refuse aerosol packaging, be it deodorants, air fresheners, etc. Do not release freon - monitor the integrity of the system in the refrigerator, car, etc.

Protest together with the “greens”, sign appeals to the governments of the world - the more activists, the more more chance that you will be heard.

The General Assembly declared the International Day for the Preservation of the Ozone Layer in 1994. In 1987, Russia and 36 other countries signed a document obliging participating countries to limit or stop the production of ozone-depleting substances.

Large enterprises are being monitored everywhere to see how they comply with safety legislation. atmospheric air. Countries have stopped the production of chlorofluorocarbons. Scientists believe that these measures taken (if humans are the culprit) will help renew the ozone layer by 2060, but until then, ozone layer depletion will greatly affect the climate.

In the upper part of the Earth's stratosphere, at an altitude of 20 to 50 km, there is a layer of ozone - triatomic oxygen. Under the influence of ultraviolet radiation, a molecule of ordinary oxygen (O2) attaches another atom, and as a result, an ozone molecule (O3) is formed.

Protective layer of the planet

Ozone layer depletion

In the 70s, during research, it was noticed that freon gas, used in air conditioners, refrigerators, etc., destroys ozone at a tremendous speed. Rising to the upper layers of the atmosphere, freons release chlorine, which decomposes ozone into ordinary and atomic oxygen. At the site of such interactions, an ozone hole is formed.

What does the ozone layer protect from?

Ozone holes are ubiquitous, but as many factors change, they are covered by ozone from neighboring layers of the atmosphere. Those, in turn, become even more subtle. The ozone layer is the only barrier to destructive ultraviolet and radiation exposure sun. Without the ozone layer, the immune system would be destroyed.

Scientists estimate that a decrease in the ozone layer by just 1% increases the likelihood of cancer by 3-6%.

A decrease in the amount of ozone in the atmosphere will unpredictably change the climate on the planet. Because the ozone layer dissipates heat from the Earth's surface, as the ozone layer depletes, the climate will become colder and the direction of some winds will change. All this will lead to natural disasters.

Montreal Protocol

In 1989, the majority of UN member states signed an agreement according to which the production of ozone-depleting freons and gases must be stopped. According to, after the signing of the agreement, the ozone layer should be fully restored by 2050.

Video on the topic

Sources:

• What is the ozone layer for?

Ozone holes are areas in the Earth's ozone layer where the ozone gas, which protects the planet from radiation, is very low. Usually the process of their formation is associated with human activity, but there is an opinion that the origin of ozone holes is absolutely natural.

Ozone hole

It has been proven that freons released during the operation of many devices cause ozone loss in middle and high latitudes, but they do not affect the formation of polar ozone holes.

It is likely that the totality of many, both human and natural factors, led to the formation of ozone holes. On the one hand, it has increased volcanic activity, on the other hand, people have begun to seriously influence nature - the ozone layer can not only be caused by the release of freon, but also from collisions with failed satellites. Thanks to a decrease in the number of erupting volcanoes since the end of the 20th century and restrictions on the use of freons, the situation has begun to improve slightly: scientists recently recorded a small hole over Antarctica. A more detailed study of ozone depletion will make it possible to prevent the emergence of these areas.

Tip 6: How to celebrate International Ozone Day

September 16, 1987 at Canadian city Montreal Delegates from 36 countries signed the Montreal Protocol. Each of these 36 states took upon itself the obligation to take all possible measures to gradually limit, and in the future, completely stop the production and use of substances that destroy the ozone layer earth's atmosphere.

This day was first celebrated in Russia in 2011. Employees of the Ministry of Natural Resources of the Russian Federation, the Global Environment Facility (GEF) and representatives of the UN took part in the program prepared and implemented on the basis of the State Polytechnic College No. 19 - the only educational institution Russia, training specialists in the field of installation and maintenance of industrial and domestic refrigeration equipment. The choice was not accidental, because the main source of destruction of the ozone layer is fluorinated refrigerants. And in order to control the reliability of refrigeration equipment, preventing leaks of refrigerants into the environment, as well as gradually reducing the volume of their production and use, qualified specialists in this field are needed.

On September 16 this year, Moscow will also celebrate Ozone Layer Protection Day. In addition to traditional reports and information on the results of observations of the thickness of the ozone layer in the polar regions, data on measures taken on regulating the circulation of ozone-depleting substances in Russia. There will be training computer games, dedicated to the topic of preserving the ozone layer. And in conclusion holiday will be shown concert program.

Video on the topic

Since the poles experience long polar nights, the temperature drops sharply in these places and stratospheric clouds containing ice crystals form. As a result, molecular chlorine accumulates in the air, the internal bonds of which are broken with the onset of spring and the appearance of solar radiation.

A chain of chemical processes that occurs when chlorine atoms rush into the atmosphere leads to the destruction of ozone and the formation of ozone holes. When the sun begins to shine in full force, air masses with a new portion of ozone are sent to the poles, due to which the hole is closed.

Why do ozone holes appear?

There are many reasons for the appearance of ozone holes, but the most important of them is human pollution of the natural environment. In addition to chlorine atoms, ozone molecules destroy hydrogen, oxygen, bromine and other combustion products that enter the atmosphere due to emissions from factories, factories, and flue gas power plants.
Nuclear tests have no less impact on the ozone layer: during explosions, a huge amount of energy is released and nitrogen oxides are formed, which react with ozone and destroy its molecules. It is estimated that only from 1952 to 1971, with nuclear explosions About 3 million tons of this substance entered the atmosphere.

The formation of ozone holes is also facilitated by jet planes, in the engines of which nitrogen oxides are also formed. The higher the power of a turbojet engine, the higher the temperature in its combustion chambers and the more nitrogen oxides enter the atmosphere. Research estimates that 1 million tons of nitrogen is released into the air each year, a third of which comes from airplanes. Another reason for the destruction of the ozone layer is mineral fertilizers, which, when introduced into the ground, react with soil bacteria. In this case, nitrous oxide enters the atmosphere, from which oxides are formed.

What consequences can ozone holes have for humanity?

Due to the weakening of the ozone layer, the flow increases solar radiation, which in turn can lead to the death of plants and animals. The impact of ozone holes on humans is expressed primarily in an increase in the number of skin cancers. Scientists have calculated that if the concentration of ozone in the atmosphere drops by even 1%, the number of cancer patients will increase by about 7,000 people per year.
That is why environmentalists are now sounding the alarm and trying to take all necessary measures to protect the ozone layer, and designers are developing environmentally friendly mechanisms (airplanes, missile systems, ground transport), emitting less nitrogen oxides into the atmosphere

Acid rain

Acid rain - all types of meteorological precipitation - rain, snow, hail, fog, sleet - in which there is a decrease in the pH (hydrogen value) of rainfall due to air pollution with acidic oxides, usually sulfur oxides and nitrogen oxides [

Acid rain is one of the terms that industrialization brought to humanity. The indefatigable consumption of the planet's resources, the huge scale of fuel combustion, and environmentally imperfect technologies are clear signs of the rapid development of industry, which is ultimately accompanied by chemical pollution water, air and land. Acid rain is just one manifestation of such pollution.

First mentioned back in 1872, The concept became truly relevant only in the second half of the 20th century. Currently, acid rain is a problem for many countries around the world, including the United States and almost all European countries. The acid rain map, developed by ecologists around the world, clearly shows the zones of the most high risk dangerous precipitation.

CAUSES OF ACID RAIN

All rainwater has a certain level of acidity.. But in the normal case, this indicator corresponds to a neutral pH level - 5.6-5.7 or slightly higher. The slight acidity is due to the carbon dioxide content in the air, but is considered so low that it does not cause any harm to living organisms. Thus, the causes of acid rain are solely due to human activities and cannot be explained by natural causes.

Preconditions for increasing the acidity of atmospheric water arise when industrial enterprises emit large volumes of sulfur oxides and nitrogen oxides. The most typical sources of such pollution are vehicle exhaust gases, metallurgical production and thermal power plants (CHP). Unfortunately, modern level The development of purification technologies does not allow filtering out nitrogen and sulfur compounds that arise as a result of the combustion of coal, peat, and other types of raw materials that are used in industry. As a result, such oxides enter the atmosphere, combine with water as a result of reactions under the influence of sunlight, and fall to the ground in the form of precipitation, which is called “acid rain.”

CONSEQUENCES OF ACID RAIN

Scientists note that the consequences of acid rain are very multidimensional and dangerous for both people, animals and plants. Among the main ones, experts name the following effects:

1. Acid rain significantly increases the acidity of lakes, ponds, and reservoirs, as a result of which their natural flora and fauna are gradually dying out. As a result of changes in the ecosystem of water bodies, they become swamped, clogged, and have increased silt. In addition, as a result of such processes, water becomes unsuitable for human use. Its salt content increases heavy metals and various toxic compounds that are normally absorbed by the microflora of the reservoir.

2. Acid rain leads to forest degradation and plant extinction. Coniferous trees are especially affected, since the slow renewal of foliage does not give them the opportunity to independently eliminate the effects of acid rain. Young forests are also very susceptible to such precipitation, the quality of which is rapidly declining. With constant exposure to water with high acidity, trees die.

3. In the USA and Europe acid rain is one of the common causes of poor harvests, extinction of agricultural crops over vast areas. Moreover, the reason for such damage lies both in the direct effect that acid rain has on plants and in disturbances in soil mineralization.

4. Acid rain causes irreparable damage to architectural monuments, buildings, and structures. The action of such precipitation causes accelerated corrosion of metals and failure of mechanisms.

5. With the current acidity that acid rain has, in some cases it can cause direct harm to humans and animals. First of all, people in high-risk areas suffer from diseases of the upper respiratory tract . However, the day is not far off when the saturation of harmful substances in the atmosphere will reach a level at which sufficiently high concentrations of sulfuric and nitrate acid will fall out in the form of precipitation. In such a situation, the threat to human health will be significantly higher.

HOW TO DEAL WITH ACID RAIN?

It is almost impossible to deal with precipitation itself. Falling on vast territories, acid rain causes significant damage, and there is no constructive solution to this problem.

Another thing is that in the case of acid rain it is critically necessary to fight not the consequences, but the causes of this phenomenon. The search for alternative sources of energy production, environmentally friendly vehicles, new production technologies and technologies for purifying emissions into the atmosphere is an incomplete list of what humanity must attend to so that the consequences do not become catastrophic.

Tropical forests are a unique plant community characterized by species richness of plants and animals. It is no coincidence that white travelers have earned these places the respectful name of “green hell” for their inaccessibility, mystery and dangers that await everyone who dares to enter here at every step. Unfortunately, this ecosystem, which has undergone the least changes over the entire existence of the land, is today disappearing at an alarming rate, and what was created by nature over millions of years can be destroyed by humans in a matter of decades. The consequences may become unpredictable.

Species distribution of vegetation on globe depends on the climate and is zonal in nature. The most amazing of these zones are tropical forests, growing in areas with the most favorable conditions for plant growth and development. This is facilitated by the climate - this zone is characterized by high, but not excessive, temperatures and heavy rainfall. Daily and annual temperature fluctuations are small, and as a result, in tropical forests there are no changes in seasons, and all days are similar to each other. Length daylight hours also remains virtually unchanged throughout the year. In short, here they are practically created for plants. ideal conditions for life. In tropical forests, organic life literally boils. Before the tree has time to die, it is immediately attacked by hordes of fungi, bacteria and insects, and in a matter of days the forest giants completely decompose into simpler substances, providing food for many other species. Therefore, the soil in tropical forests is unusually poor, and in its productivity cannot be compared with rich lands temperate zone- the thickness of the humus under the canopy of the tropical forest barely reaches a few millimeters.

It cannot be more powerful, because falling leaves decompose very quickly, and everything that has even the slightest nutritional value is immediately consumed by numerous people who want it. Thanks to the intensive turnover of organic matter over millions of years, tropical forests have developed an ideal balance. Surely this would have continued further, but man came and began to exploit natural resources in a barbaric manner. And if there are no trees, then without that thin layer humus will quickly be depleted. The burning rays of the sun, touching the ground, quickly dry it out and destroy the bacteria that decompose organic matter, and under the thin life-giving humus there are barren soils, devoid of even signs of organic life. So the place of cut down trees is very quickly taken by a lifeless desert. In world markets, the wood of many types of tropical trees is highly valued, so it is not surprising that large trading companies began logging it at any cost. The most valuable tree species from a business point of view grow interspersed with other species, without creating separate groups - and in order to obtain them, harvesters are forced to destroy large forest areas.

When they fall, forest giants crush other plants, and heavy equipment that transports trunks for processing causes irreparable damage to the forest, destroying the top layer of soil with its tracks and wheels. However, mining of valuable tree species is not the only threat equatorial forests, which are massively consumed by fire. Fires in these places rage for two main reasons: firstly, sometimes the removal of low-value tree species is not justified, and loggers simply burn them right at the felling site; the second reason is human agricultural activity. First of all, we are talking about primitive tribes that have survived in tropical forests to this day and clear places for their fields in the most primitive way - by burning the forest.

However, one could still come to terms with this damage, because after the departure of the tribe, after two or three years, the relatively small burned areas of the forest, as a rule, are restored.

But the main danger is that such a primitive process of expanding arable land in many equatorial countries is becoming national scale, And environmental situation is changing dramatically - in the depths of tropical forests, vast fields are increasingly appearing, around which settlements of farmers are growing. Such expansion occurs, for example, in Brazil, where, in search of economic reserves, the government is investing huge amounts of money in promoting the agricultural sector deep into the Amazon forests. In some areas of tropical forests, deposits of valuable minerals have been discovered, and if the economic feasibility of their development is confirmed, the exploitation of raw materials by the cheapest begins very quickly open method- one of these quarries in the Amazon covers an area of ​​several hundred square kilometers.

Brazil has adopted a government program to create chemical and pharmaceutical enterprises in the Amazon. Huge spaces along the banks of the Amazon are poisoned by mercury, which is used by gold miners. When highways are built that cut through tropical forests, wide asphalt strips disrupt the unity of the ecosystem and threaten the lives of animals. There are many rivers in tropical forests that are famous for their picturesque waterfalls. However, for economic development this natural beauty does not matter - civilized visitors are only interested in the profit hidden in the free energy that rivers can provide. Therefore, in tropical forests there is a rapid construction of hydroelectric power stations with the appearance of a whole system of dams - and then huge forest areas are flooded, the balance of surface and groundwater changes.

Meanwhile, the huge green mass of tropical forests plays an extremely important role in stabilizing the earth's atmosphere. During the process of photosynthesis, leaves absorb carbon dioxide and produce oxygen, which is of great importance for maintaining the balance of these gases in nature and saving the planet from threats to it. greenhouse effect. Reducing the green cover by half can be compared to an operation in which one lung was cut out from a healthy person. Tropical forests grow in areas with high rainfall. But this precipitation is largely due to humid forests, which, through the process of evaporation, supply an incredibly large amount of water vapor into the atmosphere. The destruction of forests leads to the disappearance of water and shade, and the scorching hot sun in these latitudes very quickly completes the process of desertification. Scientists have estimated that today a billion farmers live in cultivated areas that once made up tropical forests. Climatologists are sounding the alarm - if tropical forests continue to be destroyed at the same rate, the planet faces global drought, rising temperatures and the occurrence of unabated hurricanes.

The shrinking area of ​​tropical forests also poses a threat such as the irreparable loss of many species of flora and fauna. It was found that 45% of all plant species, 96% of arthropods, 45% of mammals and 30% of birds lived in pristine tropical forests. With the destruction of forests, many species disappeared, and at the same time the biological diversity of the planet decreased - and with each disappearing species, humanity loses some part of the genetic information accumulated on Earth. By the way, among the dying species there are many that are not even known to science, and it is possible that in the leaves, roots and fruits of some unknown plants there are chemical compounds that can cure, for example, malignant tumors. Animals also die - most often due to the fact that people change or destroy their usual habitat.

The fate of tropical forests worries thousands of people and dozens of organizations who are making efforts to curb the process of extermination of a unique biocenosis. There are different ways to protect nature. Large environmental organizations in European countries and North America boycott the sale of tropical wood products; in turn, the International Tropical Timber Trade Society has developed methods rational use this type of raw material.

All this is being done not only because of love for nature - there is also a sound commercial calculation: economists have calculated that a predatory attitude towards forests will sooner or later lead to a decline in timber trade, so some countries are beginning to create plantations of valuable species of tropical trees. Only future generations will feel the benefits of this - such trees grow for decades. But today, a number of products are assigned a mark that indicates that the product is made from wood grown on a plantation. However, the best option to preserve tropical forests in their original form is to create a network of national parks. The action that allowed private individuals to purchase small areas of tropical forest had a great moral impact - from such symbolic purchases a national park in Costa Rica eventually emerged.

Countries with tropical forests already understand that it is better to make money from rich tourists who with my own eyes want to see the unique diversity of tropical flora and fauna rather than destroy this constant source of profit. More and more companies are joining the paper and cardboard collection and recycling program. The International Monetary Fund has provided financial assistance to Indonesia to compensate for the damage caused by the liquidation of a corrupt timber trading consortium in the country. The world of science and politics is increasingly holding conferences on protecting the “green lungs of the Earth.” Will all this bring quick results- unknown. But there remains hope that in the coming years the avalanche-like reduction in the area of ​​tropical forests will stop.

Related information.

Ozone layer- this is a layer of the atmosphere (stratosphere) with a high content of ozone. It starts at an altitude of about 8 km above the poles (or 17 km above the equator) and extends up to 50 km. The concentration of ozone in the layer is very low, and if it is isolated in its pure form and compressed to the density that air has at the surface of the Earth, then the thickness of the ozone layer will not exceed 5 mm.

Ozone- allotropic form (in the case when the element has several simple substances(they consist of atoms of the same type), they are called allotropic forms) of oxygen (from the Greek “smelling”), its molecule consists of three oxygen atoms (O3). Ozone is formed from oxygen under the influence of ultraviolet radiation:

Ozone absorbs hard (short-wave) ultraviolet radiation from the Sun, protecting living organisms from its harmful effects. Therefore, the destruction of the ozone layer will lead to more high levels ultraviolet radiation on the surface of the Earth, which will contribute to an increase in cases of skin cancer in humans, mutations in plants, etc.

In 1985, British researchers published data from their eight years of observations. They discovered areas of the atmosphere above the North and South Poles with low ozone content (up to 50%) - “ozone holes”. Currently, most scientists have come to the conclusion that the ozone layer of the earth is destroyed by the so-called freons - chlorofluorocarbons (CFCs), extremely chemically resistant substances used as refrigerants in refrigerators and fillers in aerosol packaging. Thanks to chemical resistance Nothing in nature can destroy (recycle) freons. Diffusing in the atmosphere, freon vapor reaches the ozone layer and there, under the influence of ultraviolet radiation, it interacts with ozone and “eats” a hole in the ozone layer.

In mid-September 1987, representatives of twenty-four countries met in Montreal and signed an agreement under which they pledged to halve the use of ozone-depleting CFCs by 1999. However, due to the worsening situation, amendments to the Montreal Protocol were adopted in London in 1990, according to which ten more substances were added to the list of regulated CFCs. It was decided to phase out the use of CFCs, halogens and carbon tetrachloride (CCl4) by 2000, and methyl chloroform by 2005.

As a result of all these ban measures, “ozone holes,” unfortunately, did not disappear or even decrease. It is possible that it is not freons that are to blame for their existence, but natural causes: cyclical activity of the Sun, the process of degassing of the Earth, etc. In any case, “ozone holes” pose a threat to humanity and require constant environmental monitoring(observation) of them.

Another problem concerning ozone, but not related to the destruction of the ozone layer, is photochemical smog: formed in the light during reactions of nitrogen oxides with hydrocarbons, ozone, collecting in the lower layers of the atmosphere (troposphere), is an integral part of smog.

The presence of ozone in the troposphere accelerates the destruction of rubber products, textiles, paint coatings, etc., reduces the productivity of agricultural crops, slows down photosynthesis in plants and weakens them. Thus, according to experts, in the United States, annual losses of corn, wheat, soybeans and peanuts caused by ozone range from 1.9 to 4.5 billion dollars.

Recently, the public is increasingly concerned about environmental issues - protection environment, animals, reducing the amount of harmful and hazardous emissions. Surely everyone has also heard about what an ozone hole is, and that there are a lot of them in the modern stratosphere of the Earth. This is true.

Modern anthropogenic activities and technological development threaten the existence of animals and plants on Earth, as well as the very lives of people.

The ozone layer is the protective shell of the blue planet, which is located in the stratosphere. Its height is approximately twenty-five kilometers from earth's surface. And this layer is formed from oxygen, which under the influence of solar radiation undergoes chemical transformations. A local decrease in ozone concentration (in common parlance this is the well-known “hole”) is currently caused by many reasons. First of all, this is, of course, human activity (both production and everyday life). There are, however, opinions that the ozone layer is destroyed under the influence of natural phenomena, not related to people.

Anthropogenic influence

Having understood what the ozone hole is, it is necessary to find out what kind of human activity contributes to its appearance. First of all, these are aerosols. Every day we use deodorants, hairsprays, eau de toilettes with spray bottles and often don’t think about the fact that this has a detrimental effect on our health. protective layer planets.

The fact is that the compounds that are present in the cans we are used to (including bromine and chlorine) readily react with oxygen atoms. Therefore, the ozone layer is destroyed, turning after such chemical reactions into completely useless (and often harmful) substances.

Destructive compounds for the ozone layer are also present in air conditioners, which are life-saving in the summer heat, as well as in cooling equipment. Widespread human industrial activity also weakens the earth's defenses. It is oppressed by industrial water (some of the harmful substances evaporate over time), polluting the stratosphere and cars. The latter, as statistics show, is becoming more and more numerous every year. Negatively affects the ozone layer and

Natural influence

Knowing what an ozone hole is, you also need to have an idea of ​​how many there are above the surface of our planet. The answer is disappointing: there are many gaps in earthly defenses. They are small and often represent not a hole, but a very thin remaining layer of ozone. However, there are also two huge unprotected spaces. This is the Arctic and Antarctic ozone hole.

The stratosphere above the Earth's poles contains almost no protective layer at all. What is this connected with? There are no cars there and industrial production. It's all about natural influence, the second reason Polar vortexes arise when warm and cold air currents collide. These gas formations in large quantities contain nitric acid, which is very influenced low temperatures and reacts with ozone.

Environmentalists began to sound the alarm only in the twentieth century. Destructive ones that make their way to the ground without encountering an ozone barrier can cause skin cancer in humans, as well as the death of many animals and plants (primarily marine ones). So, international organizations Almost all compounds that destroy the protective layer of our planet were banned. It is believed that even if humanity suddenly stops all negative impact on ozone in the stratosphere, the currently existing holes will not disappear very soon. This is explained by the fact that freons that have already made their way to the top are able to independently exist in the atmosphere for decades to come.