Global environmental problems are caused first. Global environmental issues

Continuous technological progress, the continuing enslavement of nature by man, industrialization, which has changed the surface of the Earth beyond recognition, have become the causes of the global ecological crisis. Currently, the population of the planet is particularly acute environmental problems such as air pollution, ozone depletion, acid rain, greenhouse effect, soil pollution, pollution of the world's oceans and overpopulation.

Global Environmental Issue #1: Air Pollution

Every day, the average person inhales about 20,000 liters of air, which contains, in addition to vital oxygen, a whole list of harmful suspended particles and gases. Air pollutants are conditionally divided into 2 types: natural and anthropogenic. The latter prevail.

The chemical industry is not doing well. Factories emit such harmful substances as dust, oil ash, various chemical compounds, nitrogen oxides and much more. Air measurements showed the catastrophic state of the atmospheric layer, polluted air causes many chronic diseases.

Atmospheric pollution is an environmental problem, familiar to the inhabitants of absolutely all corners of the earth. It is especially acutely felt by representatives of cities where ferrous and non-ferrous metallurgy, energy, chemical, petrochemical, construction and pulp and paper industries operate. In some cities, the atmosphere is also heavily poisoned by vehicles and boilers. These are all examples of anthropogenic air pollution.

What about natural sources? chemical elements polluting the atmosphere, these include forest fires, volcanic eruptions, wind erosion (dispersal of soil and rock particles), the spread of pollen, evaporation of organic compounds and natural radiation.

Consequences of atmospheric pollution

Atmospheric air pollution adversely affects human health, contributing to the development of heart and lung diseases (in particular, bronchitis). In addition, atmospheric pollutants such as ozone, nitrogen oxides and sulfur dioxide destroy natural ecosystems, destroying plants and causing the death of living creatures (particularly river fish).

The global environmental problem of atmospheric pollution, according to scientists and government officials, can be solved in the following ways:

• limiting population growth;
• reduction in energy use;
• improving energy efficiency;
• waste reduction;
• transition to environmentally friendly renewable energy sources;
• air purification in highly polluted areas.

Global Environmental Issue #2: Ozone Depletion

The ozone layer is a thin strip of the stratosphere that protects all life on Earth from the harmful ultraviolet rays of the sun.

Causes of the environmental problem

Back in the 1970s. environmentalists have discovered that the ozone layer is destroyed by exposure to chlorofluorocarbons. These chemicals are found in coolants in refrigerators and air conditioners, as well as solvents, aerosols/sprays, and fire extinguishers. To a lesser extent, other anthropogenic influences also contribute to the thinning of the ozone layer: the launch of space rockets, flights of jet aircraft in high layers of the atmosphere, tests nuclear weapons, deforestation of the planet. There is also a theory that global warming contributes to the thinning of the ozone layer.

Consequences of ozone depletion

As a result of the destruction of the ozone layer, ultraviolet radiation passes unhindered through the atmosphere and reaches the earth's surface. Exposure to direct UV rays adversely affects people's health by weakening the immune system and causing diseases such as skin cancer and cataracts.

World Environmental Issue #3: Global Warming

Like the glass walls of a greenhouse, carbon dioxide, methane, nitrous oxide and water vapor allow the sun to heat our planet and at the same time prevent infrared radiation reflected from the earth's surface from escaping into space. All these gases are responsible for maintaining the temperature acceptable for life on earth. However, the increase in the concentration of carbon dioxide, methane, nitrogen oxide and water vapor in the atmosphere is another global environmental problem, called global warming (or the greenhouse effect).

Causes of global warming

During the 20th century average temperature on the ground increased by 0.5 - 1? C. The main cause of global warming is considered to be an increase in the concentration of carbon dioxide in the atmosphere due to an increase in the volume of fossil fuels burned by people (coal, oil and their derivatives). However, according to the statement Alexey Kokorin, head of climate programs World Fund wildlife (WWF) Russia, "nai large quantity greenhouse gases are generated by power plants and methane emissions during the extraction and delivery of energy resources, while road transport or associated petroleum gas flaring causes relatively little environmental damage..

Other prerequisites for global warming are overpopulation of the planet, deforestation, ozone depletion and littering. However, not all environmentalists hold responsibility for increasing average annual temperatures entirely on anthropogenic activity. Some believe that the natural increase in the abundance of oceanic plankton also contributes to global warming, leading to an increase in the concentration of the same carbon dioxide in the atmosphere.

Consequences of the greenhouse effect

If the temperature during the 21st century increases by another 1 ? C - 3.5 ? C, as scientists predict, the consequences will be very sad:

• the level of the world ocean will rise (due to the melting of polar ice), the number of droughts will increase and the process of land desertification will intensify,
• many species of plants and animals adapted to existence in a narrow range of temperatures and humidity will disappear,
• hurricanes will increase.

Solving an environmental problem

To slow down the process of global warming, according to environmentalists, the following measures will help:

• rising prices for fossil fuels,
• replacement of fossil fuels with environmentally friendly ones (solar energy, wind energy and sea currents),
• development of energy-saving and waste-free technologies,
• taxation of emissions in environment,
• minimization of methane losses during its production, transportation through pipelines, distribution in cities and villages and use at heat supply stations and power plants,
• introduction of carbon dioxide absorption and binding technologies,
• tree planting,
• reduction in family size
• environmental education,
• application of phytomelioration in agriculture.

Global Environmental Issue #4: Acid Rain

Acid rain, containing fuel combustion products, also poses a threat to the environment, human health, and even to the integrity of architectural monuments.

Consequences acid rain

Contained in polluted precipitation and fog solutions of sulfuric and nitric acid, aluminum and cobalt compounds pollute the soil and water bodies, adversely affect vegetation, causing dry tops deciduous trees and oppressing conifers. Due to acid rain, crop yields are falling, people are drinking water enriched with toxic metals (mercury, cadmium, lead), marble architectural monuments are turning into gypsum and eroding.

Solving an environmental problem

In order to save nature and architecture from acid rain, it is necessary to minimize the emissions of sulfur and nitrogen oxides into the atmosphere.

Global Environmental Issue #5: Soil Pollution

Every year people pollute the environment with 85 billion tons of waste. Among them are solid and liquid waste from industrial enterprises and transport, agricultural waste (including pesticides), household waste and atmospheric fallout of harmful substances.

The main role in soil pollution is played by such components of industrial waste as heavy metals (lead, mercury, cadmium, arsenic, thallium, bismuth, tin, vanadium, antimony), pesticides and petroleum products. From the soil, they penetrate into plants and water, even spring water. In a chain, toxic metals enter the human body and are not always quickly and completely removed from it. Some of them tend to accumulate over many years, provoking the development of serious diseases.

Global Environmental Issue #6: Water Pollution

Pollution of the oceans, underground and surface water sushi is a global environmental problem, the responsibility for which lies entirely with man.

Causes of the environmental problem

The main pollutants of the hydrosphere today are oil and oil products. These substances penetrate into the waters of the oceans as a result of the collapse of tankers and regular discharges of wastewater from industrial enterprises.

In addition to anthropogenic oil products, industrial and domestic facilities pollute the hydrosphere with heavy metals and complex organic compounds. Agriculture and the food industry are recognized as the leaders in poisoning the waters of the oceans with minerals and biogenic elements.

The hydrosphere does not bypass such a global environmental problem as radioactive contamination. The prerequisite for its formation was the disposal of radioactive waste in the waters of the oceans. From the 1949s to the 1970s, many powers with a developed nuclear industry and atomic fleet purposefully stockpiled harmful radioactive substances into the seas and oceans. In the places of burial of radioactive containers, the level of cesium often goes off scale even today. But "underwater polygons" are not the only radioactive source of pollution of the hydrosphere. The waters of the seas and oceans are enriched with radiation as a result of underwater and surface nuclear explosions.

Consequences of radioactive contamination of water

Oil pollution of the hydrosphere leads to the destruction of the natural habitat of hundreds of representatives of oceanic flora and fauna, the death of plankton, seabirds and mammals. For human health, the poisoning of the waters of the oceans also poses a serious danger: fish and other seafood “infected” with radiation can easily get on the table.

Assel 17.05.2019 12:14
http://www.kstu.kz/

Jan 31.05.2018 10:56
To avoid all this, it is necessary to solve everything not for the state budget, but for free!
And besides, you need to add environmental protection laws to your constitution of your country.
namely, strict laws that should make at least 3% of environmental pollution not
only of their homeland but also of all countries of the world!

24werwe 21.09.2017 14:50
The cause of air pollution soil water crypto-Jews. There are degenerates with signs of Jews on the streets. Greenpeace and environmentalists vile kriptoreyskie TV-ri. They are engaged in eternal criticism according to the Catechism of the Jew in the USSR (according to the Talmud). Promote dosed poisoning. They do not name the reason - the deliberate destruction of all living things by the Jews hiding under the labels of "peoples". There is only one way out: the destruction of the Jews with their agriculture and the cessation of production.

Topic 11.Global environmental problems of our time

11.1. Global environmental problems, causes and consequences.

11.2. Preservation of natural ecosystems and biodiversity.

11.1. Global environmental problems, causes and consequences.

The global environmental problem consists in the difficulties of overcoming the ecological crisis that has arisen on our planet due to the destructive impact of people on nature. The main manifestations of the ecological crisis are most often referred to as the following:

1. Pollution of the air and water basins of the Earth, the formation of the greenhouse effect, “ozone holes”, “acid rain”, poisoned rivers and lakes, entire zones of ecological disaster with human diseases, etc.

2. Global climate change threatening a climate catastrophe in the future (general warming, weather instability, droughts, melting of polar ice caps, rising sea levels, flooding of vast territories, fertile lands, etc.).

3. Reduction of arable land and deterioration of soil fertility due to their overexploitation, erosion, poisoning, salinization, waterlogging, desertification, absorption by cities and industry, etc.

4. Destruction and extinction of forests, impoverishment of the animal and flora, a huge amount of waste, etc.

Man is a part of nature, and the most dangerous disasters for our planet and environmental pollution are associated with him. The scientific and technological revolution, the enormous growth of industry and the increased productive activity of man are changing the face of our planet. In the history of mankind, a period has now come when society is forced to clearly measure its activity with the possibilities of nature. “Before, nature frightened man, but now man frightens nature,” according to French researcher Jacques Yves Cousteau. Having entered the era of rapid scientific and technological progress, most people do not think about the possible consequences of unlimited exploitation natural resources, do not care about the fate of the biosphere, which experiences all the consequences of human economic activity.

The Earth is a unique celestial body in the solar system and the only one of the planets has a biosphere that arose under the influence of solar energy as a result of long-term biochemical processes.

Man, as an element of the biosphere, appeared relatively recently, about 3.2 million years ago, and until the beginning of the 20th century, his activity was of a local nature. It is man who has become a huge ecological and geochemical force, which has greatly influenced the change in the ecological situation over the past 50 years. Now human activity already covers the entire biosphere and is global. Mankind has entered the industrial age of intense pressure on the environment in all areas: ground, air, underground.

Consider some of the environmental consequences of global atmospheric pollution:

Possible climate warming (“greenhouse effect”);

Deterioration of the ozone layer;

Fallout of acid rain.

"Greenhouse effect"

Currently, the observed climate change, which is expressed in a gradual increase in the average annual temperature, most scientists associate with the accumulation in the atmosphere of the so-called "greenhouse gases" - carbon dioxide (CO 2), methane (CH 4), chlorofluorocarbons (freons), ozone ( O 3), nitrogen oxides, etc.

Greenhouse gases, primarily CO 2 , prevent long-wavelength thermal radiation from the Earth's surface. According to G. Hoefling, an atmosphere saturated with greenhouse gases acts like the roof of a greenhouse. On the one hand, it lets in most of the solar radiation, and on the other hand, it almost does not let the heat reradiated by the Earth out.

In connection with the burning of more and more fossil fuels: oil, gas, coal, the concentration of CO 2 in the atmosphere is constantly increasing.

In a report prepared under the auspices of the United Nations by an international group on climate change, it is argued that by the year 2100 the temperature on Earth will increase by 2-4 degrees. The scale of warming in this relatively short period will be comparable to the warming that occurred on Earth after the Ice Age, which means that the environmental consequences can be catastrophic. First of all, this is due to the expected rise in the level of the World Ocean, due to the melting of polar ice, and the reduction in the areas of mountain glaciation. Modeling the environmental consequences of an ocean level rise of only 0.5-2.0 m by the end of the 21st century, scientists have found that this will inevitably lead to climate imbalance, flooding of coastal plains in more than 30 countries, degradation of permafrost, and waterlogging of vast areas. and other adverse effects.

Acid rain.

The term "acid rain" refers to all types of meteorological precipitation - rain, snow, hail, fog, sleet - whose pH is less than the average pH of rainwater (the average pH for rainwater is 5.6). Sulfur dioxide (SO 2) and nitrogen oxides (NOx) released during human activity are transformed into acid-forming particles in the earth's atmosphere. These particles react with atmospheric water, turning it into acid solutions, which lower the pH of rainwater. For the first time the term "acid rain" was introduced in 1872 by the English researcher A. Smith. His attention was drawn to the Victorian smog in Manchester. And although scientists of that time rejected the theory of the existence of acid rain, today no one doubts that acid rain is one of the causes of the death of life in reservoirs, forests, crops, and vegetation. In addition, acid rain destroys buildings and cultural monuments, pipelines, renders cars unusable, reduces soil fertility and can lead to seepage of toxic metals into aquifers.

The consequences of acid rain are observed in the USA, Germany, the Czech Republic, Slovakia, the Netherlands, Switzerland, Australia, the republics of the former Yugoslavia and in many other countries of the globe.

Acid rain has a negative impact on water bodies - lakes, rivers, bays, ponds - increasing their acidity to such a level that flora and fauna die in them. Acid rain harms more than just aquatic life. It also destroys vegetation on land. Scientists believe that although the mechanism has not yet been fully understood to this day, a complex mixture of pollutants, including acid precipitation, ozone, and heavy metals, together lead to forest degradation.

Ozone layer.

Depletion of the Earth's ozone layer is a potential threat to human, animal, plant and microbial health. Observations since 1973 show that the thickness of the ozone layer over Kazakhstan has decreased by 5-7%. Measures to control the use of substances that deplete the ozone layer, adopted in accordance with the Montreal Protocol, have contributed to a decrease in the world by 10 times compared with 1986 levels. Currently, work is underway in Kazakhstan to reduce the use of ozone-depleting substances and withdraw them from circulation, introduce new technologies using substances that do not destroy the ozone layer.

The main identified substances that deplete the ozone layer are:

Chlorofluorocarbons (HFO or CFC);

Partially halogenated chlorofluorocarbons (HHFO or HCFC);

Partially halogenated bromofluorocarbons (HBFO);

1,1,1 - trichloroethane (methyl chloroform);

Bromochloromethane (BHM);

Methyl bromide (MB);

Tetrachlorocarbon;

The main purposes of using substances that deplete the ozone layer are:

cooling units;

air conditioning devices;

warm air supply devices;

aerosols;

fire fighting systems and portable fire extinguishers;

insulating boards.

The “ozone hole” is the extremely low concentrations of ozone at the South Pole caused by the depletion of the ozone layer during the Arctic winter and spring. The area of ​​the "ozone hole" in last years was approximately 24,000,000 km 2 , and in satellite photographs it looks like a big hole. The thickness of the ozone layer in the region of the "ozone hole" is 100-150 DU (the normal thickness of the ozone layer is 300 DU).

Consequences of destruction

As a result of the destruction of the ozone layer, an increased amount of UV-B solar radiation reaches the Earth, which has a negative impact on both living beings (humans, animals, vegetation) and objects.

Consequences of too “thin” ozone layer:

the endurance of various materials (for example, rubber) decreases and, at the same time, the duration of use of these materials;

aquatic organisms living in the upper layers of water (benthos) die;

agricultural yields and fish catches are declining;

the immunity of the population against various diseases decreases;

increases the possibility of skin cancer and eye cataracts (both in humans and animals), diseases of the lungs and upper respiratory tract.

Ways to solve environmental problems:

1. Development and implementation of an agreed international environmental protection program, including such activities as:

a) creation of an international environmental fund to organize and carry out environmental measures of global importance (to stop the deforestation of tropical forests, improve the quality of drinking water, etc.);

b) establishment of international environmental standards and control over the state of the natural environment (with the right to inspect any country);

c) introduction of international quotas (norms) for harmful emissions into the atmosphere;

d) declaring the natural environment the property of all mankind and introducing the principle of “polluter pays” into international practice (for example, the introduction of an international “green tax” on harmful emissions).

2. Constant, complete and truthful informing people about the state of their environment and the formation of an ecological outlook in society.

3. Creation of reasonable environmental legislation, which should provide for high responsibility for its violation and effective incentives to encourage environmental protection (for example, the introduction of special “environmental taxes” on the use of the most “dirty” technologies and, conversely, tax incentives for environmentally friendly industries).

4. Transition to a new, environmentally friendly technological culture (rational approaches to the use of natural resources, the use of the most “clean” and least rare of them, concern for the reproduction of renewable resources, the introduction of waste-free (or low-waste), resource- and nature-saving technologies, environmental protection systems and etc.).

11.2. Preservation of natural ecosystems and biodiversity.

The ecosystems of Kazakhstan are distinguished by the uniqueness of biological diversity in Central Asia and on the continent as a whole. The disappearance of plant and animal species leads to a loss of diversity at the genetic level and a corresponding change in ecosystems. The main reason for the real loss of biodiversity is the destruction and degradation of habitats, mainly the destruction of forests, soil erosion, pollution of water bodies. More recently, the importation of alien species of plants and animals has also been recognized as a major cause of biodiversity loss.

To preserve the biodiversity of the Republic of Kazakhstan in 1994, the Convention on Biodiversity was ratified, a national strategy and action plan for the conservation and balanced use of biological diversity were developed.

The most effective measure of biodiversity conservation is the creation of specially protected natural areas. The area of ​​specially protected natural territories of the Republic of Kazakhstan is 13.5 million hectares or 4.9% of the entire territory of the entire territory, which is not enough to maintain the ecological balance of biological diversity and below world standards, which are 10%. According to the Concept for the Development and Placement of Specially Protected Natural Areas of the Republic of Kazakhstan until 2030, it is planned to increase their area to 17.5 million hectares, which will be 6.4% of the territory of the republic.

Recently, a real external threat to Kazakhstan is the import of genetically modified organisms and products that are widely distributed in the world. Considering the danger of widespread distribution of genetically modified organisms and products throughout the world, the Catagen Protocol on Biosafety of the Convention on Biodiversity was opened for signing. The implementation of these provisions of this Concept will ensure the protection of environmental objects, its content at a certain level of sustainability, the ability to self-regulate and the preservation of the diversity of forms of living and inanimate nature, including the gene pool of living organisms that are on the verge of extinction.

The level of human impact on the environment depends primarily on the technical equipment of society. She was extremely small early stages development of mankind. However, with the development of society, the growth of its productive forces, the situation begins to change dramatically. The 20th century is the century of scientific and technological progress. Associated with a qualitatively new relationship between science, engineering and technology, it colossally increases the possible and real scale of society's impact on nature, poses a number of new, extremely acute problems for humanity, primarily environmental.
What is ecology? This term, first used in 1866 by the German biologist E. Haeckel (1834-1919), refers to the science of the relationship of living organisms with the environment. The scientist believed that the new science would deal only with the relationship of animals and plants with their environment. This term has firmly entered our lives in the 70s of the XX century. However, today we are actually talking about the problems of ecology as social ecology - a science that studies the problems of interaction between society and the environment.

Today, the ecological situation in the world can be described as close to critical. Among the global environmental problems are the following:

1. - the atmosphere in many places is polluted to the maximum permissible extent, and clean air becomes scarce;

2. - the ozone layer is partially broken, protecting from cosmic radiation harmful to all living things;

3. the forest cover has been largely destroyed;

4. - surface pollution and disfigurement of natural landscapes: on Earth it is impossible to find a single square meter of the surface, where there are no elements artificially created by man.
thousands of species of plants and animals have been destroyed and continue to be destroyed;

5. - the oceans are not only depleted as a result of the destruction of living organisms, but also cease to be a regulator natural processes

6. - the available stock of minerals is rapidly declining;

7. - extinction of animal and plant species

1Atmospheric pollution

Back in the early sixties, it was believed that atmospheric pollution is a local problem of large cities and industrial centers, but later it became clear that atmospheric pollutants can spread through the air over long distances, having an adverse effect on areas located at a considerable distance from the place of emission of these substances. । Thus, air pollution is a global phenomenon, and in order to control it, it is necessary to the international cooperation.

Table 1 Ten most dangerous pollutants of the biosphere

Carbon dioxide	Formed during the combustion of all types of fuel. An increase in its content in the atmosphere leads to an increase in its temperature, which is fraught with detrimental geochemical and environmental consequences.
carbon monoxide	Formed during incomplete combustion of fuel. Can disturb the heat balance of the upper atmosphere.
Sulphur dioxide	Contained in the smoke of industrial enterprises. Causes exacerbation of respiratory diseases, harms plants. Attacks limestone and some rocks.
nitrogen oxides	They create smog and cause respiratory diseases and bronchitis in newborns. Promotes overgrowth of aquatic vegetation.
	One of the dangerous food contaminants, especially of marine origin. It accumulates in the body and has a harmful effect on the nervous system.
	added to gasoline. It acts on enzyme systems and metabolism in living cells.
	Leads to detrimental environmental consequences, causes the death of planktonic organisms, fish, seabirds and mammals.
DDT and other pesticides	Very toxic to crustaceans. They kill fish and organisms that serve as food for fish. Many are carcinogens.
radiation	In excess of permissible doses, it leads to malignant neoplasms and genetic mutations.

Among the mostcommon atmospheric pollutants include gases such as freons
। Greenhouse gases also include methane released into the atmosphere during the extraction of oil, gas, coal, as well as during the decay of organic residues, an increase in the number of cattle। Methane growth is 1.5% per year। This also includes such a compound as nitrous oxide, which enters the atmosphere as a result of the widespread use of nitrogen fertilizers in agriculture, as well as as a result of the combustion of carbon-containing fuels in combined heat and power plants। However, do not forget that despite the huge contribution of these gases to the "greenhouse effect", the main greenhouse gas on Earth is still water vapor। With this phenomenon, the heat received by the Earth does not spread into the atmosphere, but thanks to greenhouse gases remains at the Earth's surface, and only 20% of all thermal radiation earth's surface irrevocably goes into space. Roughly speaking, greenhouse gases form a kind of glass cap over the surface of the planet.

In the future, this can lead to increased ice melting and an unpredictable rise in the level of the world ocean, to the flooding of part of the coast of the continents, the disappearance of a number of plant and animal species that are unable to adapt to the new natural conditions of life. The phenomenon of "greenhouse effect" is one of the main root causes of such actual problem like global warming।

2 Ozone holes

The ecological problem of the ozone layer is no less complex in scientific terms. As you know, life on Earth appeared only after the protective ozone layer of the planet was formed, covering it from cruel ultraviolet radiation. For many centuries, nothing foreshadowed trouble. However, in recent decades, intensive destruction of this layer has been noticed.

4 Desertification

Under the influence of living organisms, water and air on the surface layers of the lithosphere

gradually formed the most important ecosystem, thin and fragile - the soil, which is called the "skin of the Earth." It is the keeper of fertility and life. A handful of good soil contains millions of microorganisms that support fertility.
It takes a century to form a layer of soil with a thickness (thickness) of 1 centimeter. It can be lost in one field season. Geologists estimate that before people began to engage in agricultural activities, graze livestock and plow land, rivers annually carried about 9 billion tons of soil into the oceans. Now this amount is estimated at about 25 billion tons 2 .

Soil erosion - a purely local phenomenon - has now become universal. In the US, for example, about 44% of cultivated land is subject to erosion. Unique rich chernozems with 14–16% humus content (organic matter that determines soil fertility) disappeared in Russia, which were called the citadel of Russian agriculture. In Russia, the areas of the most fertile lands with a humus content of 10-13% have decreased by almost 5 times 2 .

A particularly difficult situation arises when not only the soil layer is demolished, but also the parent rock on which it develops. Then the threshold of irreversible destruction sets in, an anthropogenic (that is, man-made) desert arises.

One of the most formidable, global and fleeting processes of our time is the expansion of desertification, the fall and, in the most extreme cases, the complete destruction of the biological potential of the Earth, which leads to conditions similar to those of a natural desert.

Natural deserts and semi-deserts occupy more than 1/3 of the earth's surface. About 15% of the world's population lives on these lands. Deserts are natural formations that play a certain role in the overall ecological balance of the planet's landscapes.

As a result of human activity, by the last quarter of the 20th century, more than 9 million square kilometers of deserts appeared, and in total they already covered 43% total area sushi 2 .

In the 1990s, desertification began to threaten 3.6 million hectares of drylands.

This represents 70% of the potentially productive drylands, or ¼ of the total land area, and this figure does not include the area of ​​natural deserts. About 1/6 of the world's population suffers from this process 2 .

According to UN experts, the current loss of productive land will lead to the fact that by the end of the century the world may lose almost 1/3 of its arable land 2 . Such a loss, at a time of unprecedented population growth and increased food demand, could be truly disastrous.

5 Pollution of the hydrosphere

One of the most valuable resources of the Earth is the hydrosphere - oceans, seas, rivers, lakes, glaciers of the Arctic and Antarctic. There are 1385 million kilometers on Earth water reserves and very few, only 25% fresh water fit for human life. And in spite of

these are people who are very crazy about this wealth and completely, randomly destroy it, polluting the water various waste. Mankind uses mainly fresh water for its needs. Their volume is slightly more than 2% of the hydrosphere, and the distribution water resources By the globe extremely uneven. In Europe and Asia, where 70% of the world's population lives, only 39% of river waters are concentrated. The total consumption of river waters is increasing from year to year in all regions of the world. It is known, for example, that early XXI century, fresh water consumption has increased 6 times, and in the next few decades it will increase by at least 1.5 times.

The lack of water is exacerbated by the deterioration of its quality. The waters used in industry, agriculture and everyday life are returned to water bodies in the form of poorly treated or generally untreated effluents. Thus, pollution of the hydrosphere occurs primarily as a result of the discharge into rivers, lakes and seas of industrial,

agricultural and domestic wastewater.
According to the calculations of scientists, soon 25,000 cubic kilometers of fresh water, or almost all of the actually available resources of such a runoff, may soon be required to dilute these very wastewaters. It is not difficult to guess that this, and not the growth of direct water intake, is the main reason for the aggravation of the problem of fresh water. It should be noted that wastewater containing the remains of mineral raw materials, products of human life enrich water bodies with nutrients, which in turn leads to the development of algae, and as a result, to waterlogging of the reservoir. Currently, many rivers are heavily polluted - the Rhine, Danube, Seine, Ohio, Volga, Dnieper, Dniester and others. Urban runoff and large landfills are often the cause of water pollution with heavy metals and hydrocarbons. Since heavy metals accumulate in marine food chains, their concentrations can reach lethal doses, which happened after a large industrial release of mercury into the coastal waters of Japan near the city of Minimata. The increased concentration of this metal in the tissues of fish has led to the death of many people and animals who have eaten the contaminated product. Increased doses of heavy metals, pesticides and petroleum products can significantly weaken the protective properties of organisms. The concentration of carcinogens in the North Sea is currently reaching enormous values. Huge reserves of these substances are concentrated in the tissues of dolphins,

being the last link in the food chain. Coastal countries North Sea Recently, a set of measures has been carried out aimed at reducing, and in the future, at a complete cessation of the discharge into the sea and the incineration of toxic waste. In addition, man carries out the transformation of the waters of the hydrosphere through the construction of hydraulic structures, in particular reservoirs. Large reservoirs and canals have a serious negative impact on the environment: they change the groundwater regime in the coastal strip, affect soils and plant communities, and, in the end, their water areas occupy large areas of fertile land.

Nowadays, pollution of the world's oceans is growing at an alarming rate. And here a significant role is played not only by pollution by sewage, but also by the ingress into the waters of the seas and oceans. a large number oil products. In general, the most polluted are the inland seas: the Mediterranean, North, Baltic, Japan, Java, and Biscay,

Persian and Mexican Gulfs. Pollution of the seas and oceans occurs through two channels. Firstly, sea and river vessels pollute water with waste products from operational activities, products of internal combustion in engines. Secondly, pollution occurs as a result of accidents when toxic substances, most often oil and oil products, enter the sea. Diesel engines ships emit harmful substances into the atmosphere, which subsequently settle on the surface of the water. On tankers, before each next loading, containers are washed to remove the remains of previously transported cargo, while the washing water, and with it the remains of cargo, are most often dumped overboard. In addition, after the delivery of the cargo, the tankers are sent to the new loading point empty, in this case, for proper navigation, the tankers are filled with ballast water, which is contaminated with oil residues during the navigation. Before loading, this water is also poured overboard. As for the legislative measures to control oil pollution during the operation of oil terminals and the discharge of ballast water from oil tankers, they were taken much earlier, after the danger of large spills became obvious.

Among such methods (or possible ways of solving the problem) can be attributed the emergence and activity of various kinds of "green" movements and organizations. In addition to the notorious « Green PeaWithe'A",distinguished not only by the scope of its activities, but also, at times, by a noticeable extremism of actions, as well as similar organizations that directly carry out environmental protection

In other words, there is another type of environmental organization - structures that stimulate and sponsor environmental activities - such as the Wildlife Fund, for example. All environmental organizations exist in one of the forms: public, private state or mixed type organizations.

In addition to various kinds of associations defending the rights of civilization gradually destroying nature, there are a number of state or public environmental initiatives in the field of solving environmental problems. For example, environmental legislation in Russia and other countries of the world, various international agreements or the system of "Red Books".

International "Red Book" - a list of rare and endangered species of animals and plants - currently includes 5 volumes of materials. In addition, there are national and even regional "Red Books".

Among the most important ways to solve environmental problems, most researchers also highlight the introduction of environmentally friendly, low-waste and waste-free technologies, the construction of treatment facilities, the rational distribution of production and the use of natural resources.

Although, undoubtedly - and this is proved by the entire course of human history - the most important direction in solving the environmental problems facing civilization is the increase in the ecological culture of man, serious environmental education and upbringing, everything that eradicates the main environmental conflict - the conflict between the savage consumer and the rational inhabitant of a fragile world, existing in the mind of man.

Activity modern man significantly changed the natural environment throughout our planet.

The essence of the modern ecological crisis is the contradiction between the almost limitless possibilities of human activity, which transforms nature, and handicapped biosphere in the resource provision of this activity.

The global nature of the current environmental crisis distinguishes it from previous crises. In this regard, the traditional methods of overcoming the crisis by moving to new territories are practically unfeasible. Changes in production methods, consumption rates and volumes of natural resource use remain real.

Over the past two or three centuries, the technical capabilities of man to change the natural environment have grown rapidly, reaching their highest point in the era of scientific and technological progress. However, it turned out that the growth of man's power most often led to an increase in the negative consequences for nature and, ultimately, dangerous for the existence of man himself, the consequences of his activity.

Among the most acute for mankind and still unresolved environmental issues can include the following:

Demographic crisis (a sharp increase in the population of the Earth);

· urbanization;

Decrease in the area of ​​forests;

Erosion and decrease in soil fertility;

lack of fresh water;

· Negative consequences energy production;

environmental pollution;

Destruction of the ozone layer of the stratosphere;

· anthropogenic climate change;

Decrease in biological diversity (decrease in the number of species of organisms);

· Decreased resistance of natural ecosystems to anthropogenic impact;

The impact of negative changes in the natural environment on the health of the population.

The increase in the population of the Earth. The human population is characterized by a "population explosion" unprecedented in scale, that is, a sharp increase in population growth rates that has continued since the middle of the 20th century. It is especially pronounced in the developing countries of Asia, Africa and Latin America. The highest population growth has occurred in recent decades. In the late 1990s, the world's population was already 6 billion people, while in the 30s of the XX century. the population of the Earth was 2 billion people. It is believed that the population density of the Earth is approaching a critical level. However, according to many scientists, its population will eventually stabilize at the level of 10-12 billion people.

Population growth, along with the development of industry, is the second main factor in the negative impact on the biosphere, since the increase in the number of mankind is accompanied by an increase in demand for products. Agriculture and industrial production and volume of involved natural resources. These processes lead to an increase in environmental pollution and negative impact to the biosphere.

The increase in food production, the creation of new jobs, the expansion of industrial production are accompanied by the expenditure of non-renewable natural resources, but the main reason for the contradictions between man and nature is the rapid increase in the total anthropogenic load on her.

The specificity of demographic processes in different countries associated with a range of factors, including highest value have socio-economic and environmental. If in industrialized countries the impact on nature is mainly associated with technogenic pollution, then in developing countries the main impact is associated with the direct destruction of nature as a result of unreasonably high pressures on ecosystems: deforestation, exhaustion of available resources, etc.

Although total strength The population of the Earth is increasing, in some countries there is no increase in population or even its decline is observed. Thus, the birth rate in Russia throughout the XX century. declined and in the mid-60s for the first time fell below the level of simple renewal. In the late 90s of the last century, these negative trends intensified significantly, and in 1991-1992. in Russia, a unique demographic situation has developed, the graphical representation of which is called the “Russian cross” (Fig. 16.1).

The essence of this phenomenon observed in Peaceful time and in the absence of any global catastrophes, is that mortality rates in various subjects and in Russia as a whole began to steadily exceed birth rates, which leads to the extinction of the population (Fig. 16.1).

Urbanization(from lat. urbanus - urban) - the process of concentration of population and economic life in large cities. If before 1900 Only about 14% of the world's population lived in cities, but today about half of the world's population lives in cities. Cities require the highest concentration of food, water, fuel and other life support resources. Natural ecosystems are also unable to recycle the amount of waste that is generated during the life of people in cities. The main consequences of urbanization are: depletion of energy resources, environmental pollution, degradation of water, forest and soil resources, loss of agricultural land. In addition, there is evidence that in cities the incidence of people on average is twice as high as in rural areas.

Global pollution of the biosphere. Pollution is one of the most ancient problems. It arose with the appearance of the first settlements with their sewage streams and various wastes. household. But prior to the development of industrial civilization, pollution was highly limited in nature and distribution. All wastes decomposed under the action of microorganisms and were included in the cycles of substances. Starting from the second half of the XX century. in the process of production activity, a person creates synthetic substances that, in the form of waste, enter the environment (into the atmosphere, hydrosphere, soil) and are almost not involved in the biospheric circulation of substances. It is also important that synthetic materials are often toxic to living organisms.

In most cases, pollutants, spreading widely in the atmosphere, hydrosphere and soil, gradually disperse throughout the biosphere. Atmospheric transport plays the main role. Updrafts and winds carry pollutants over different distances and circulate them in the atmosphere. Anthropogenic emissions of carbon dioxide, nitrogen oxides, sulfur dioxide or mercury increase the background concentrations of these impurities in the atmosphere. Dilution of pollutants in the environment (in water or air), reducing the concentration in a given area of ​​the biosphere, does not reduce their danger to nature and humans, but only delays negative consequences.

Air pollution. The main cause of air pollution is the burning of fossil fuels. Other causes include emissions of by-products from the chemical industry, dust emissions, radioactive gases nuclear power plants, car exhausts. The main substances polluting the atmosphere are gases (90%) and solid particles (dust). Due to human activity, dust, carbon dioxide (CO 2), carbon monoxide (CO), sulfur dioxide (SO 2), methane (CH 4), nitrogen oxides (NO 2, NO, N 2 O) enter the atmosphere.

Soil pollution. Increasing soil fertility is often achieved by applying a large amount of fertilizers, using chemical protection against pests, which makes it possible to intensify agricultural production. The widespread use of artificial chemical substances leads to pollution of soils and living organisms. In addition, atmospheric precipitation, carrying pollutants, falls on the soil surface and is also a source of its pollution. Surface and ground waters wash pollutants into aquatic environment(rivers, lakes, seas).

Fertilizers are definitely needed to replenish soil reserves nutrients seized with the harvest. The desire to increase the productivity of agricultural plants leads to oversaturation of soils with fertilizers. However, according to the Law on Marginal Yield, plant productivity does not increase in direct proportion to the amount of fertilizer applied. Excess fertilizer in the soil leads to an excess of nitrogen and phosphorus in products and degrades soil structure.

Pollution of continental and oceanic waters. Numerous pollutants can be dissolved in water or carried in suspension over long distances from discharge sites. Most toxicants, in whatever phase they are - in gaseous, liquid or solid - are capable of polluting the hydrosphere.

Biological contamination in the form of sewage leads to severe bacteriological contamination and leads to the spread infectious diseases, which creates additional problems in the field of epidemiology.

chemical pollution water is the result of the release of various chemical compounds used in agriculture (pesticides and mineral fertilizers), as well as waste from industrial enterprises. Very often, industrial effluents contain substances harmful to hydrobionts, such as lead, mercury, copper, etc. Hydrocarbon pollution (oil and oil products) has become one of the main types of hydrosphere pollution in recent decades.

The environmental consequences of pollution of natural waters are manifested in the violation of the biogeochemical cycles of substances, the decrease in biological productivity, and the degradation of individual aquatic ecosystems.

Water pollution with organic substances affects the abiotic and biotic factors that act both in flowing waters (rivers) and in large stagnant water bodies (lakes, enclosed seas). In flowing waters, the discharge of waste saturated with organic matter causes a complete disruption of the functioning of the ecosystem. In this case, four zones are formed, which follow one after another downstream: 1) a degradation zone, where the waters of the river mix with the pollutant; 2) a zone of active decomposition, where fungi and bacteria, aerobic, and then anaerobic, multiply and destroy organic matter; 3) a recovery zone, where the water is gradually purified and its initial characteristics are restored; 4) clean water zone.

As a result of the active development of microorganisms in the decomposition zone, the concentration of dissolved oxygen drops sharply and the number of algae decreases. An outbreak of autotrophs (microscopic algae - phytoplankton) occurs in the third zone as a result of the appearance of nitrates and phosphates extracted by degrading microorganisms from polluting organic substances. When the removal of dissolved and suspended pollutants is completed and the initial conditions are restored, organisms reappear living in clean water. Violations of the composition of animal communities living in rivers are much more pronounced, since no animals that live in clean water can survive in the contaminated zone.

Water pollution with toxic compounds leads to the suppression of vital activity and death of organisms sensitive to this toxicant. For example, chlorine-containing insecticides, in particular DDT, inhibit photosynthesis in phytoplankton and have a strong negative effect on biocenoses due to the ability to concentrate in food chains - bioaccumulation.

One of the main factors of negative changes in the biosphere is the over-intensive exploitation of natural resources, which leads to such consequences as the destruction of vegetation cover and the deterioration of soil properties.

Vegetation destruction. First of all, it is associated with deforestation. Deforestation is one of the most acute global environmental problems. The role of forest communities in the functioning of natural ecosystems is enormous. The forest absorbs atmospheric pollution, protects the soil from erosion, regulates the runoff of surface water, prevents the decrease in the level of groundwater, etc. In addition, forests play an important role in the process of fixing free carbon dioxide in the air during photosynthesis (reducing the greenhouse effect).

A decrease in the area of ​​forests causes a violation of the cycles of oxygen and carbon in the biosphere. Although the catastrophic effects of deforestation are widely known, deforestation continues. The area of ​​forests on the planet annually decreases by almost 2%.

As a result of intensive animal husbandry, meadow ecosystems degenerate into wastelands.

Deterioration of physical chemical properties soil. Over-exploitation of land for crops is a powerful factor in the destruction of natural resources. Usually, there are four main causes of damage and destruction of land: wind and water - erosion; salinity due to improper irrigation; fertility decline; soil pollution.

Erosion is the destruction of soils as a result of the action of water or wind. Erosion processes in nature have sharply increased under the influence of man. Erosion begins, first of all, where the natural vegetation cover is destroyed, which holds the soil together with roots and reduces the intensity of air and water streams. During its history, humanity has lost about 2 billion hectares of fertile land.

Irrigated agriculture causes irrigation erosion and secondary salinization. Excess moisture in the fields causes an increase in the level of groundwater to the soil surface and their intensive evaporation. Salts dissolved in water accumulate in the upper horizon of the soil, reducing its fertility. Some scientists believe that the civilization of Ancient Babylon died from secondary soil salinization.

Land depletion is also caused by: the alienation of nutrients with the harvest and their incomplete subsequent return; loss of humus - deterioration of the water regime. As a result of depletion, the soil loses its fertility and becomes deserted.

Destruction of the Earth's ozone layer. The destruction of the ozone layer, which serves as a protective screen against ultraviolet radiation, which is harmful to living organisms, is also associated with anthropogenic changes in the atmosphere. Especially quickly the process of destruction of the ozone layer occurs over the poles of the planet, where the so-called ozone holes have appeared. In 1987 an ozone hole over the Antarctic (extending beyond the contours of the mainland) and a less significant similar formation in the Arctic were registered expanding year by year (expansion rate - 4% per year).

The danger of depleting the ozone layer is that the intensity of ultraviolet radiation harmful to living organisms can increase. Scientists believe that the main reason for the depletion of the ozone layer (screen) is the use of chlorofluorocarbons (freons) by people, which are widely used in everyday life and in production (aerosols, foaming agents, solvents, etc.). In 1990 world production ozone-depleting substances amounted to more than 1300 thousand tons. Chlorofluorocarbons, entering the atmosphere, decompose in the stratosphere with the release of chlorine atoms, which catalyze the conversion of ozone into oxygen. In the lower layers of the atmosphere, freons can persist for decades. From here they enter the stratosphere, where their content is estimated to increase by about 5% annually. It is assumed that one of the reasons for the depletion of the ozone layer may be the reduction of forests as oxygen producers on Earth.

global climate change. At present, anthropogenic emissions (emissions) of gases (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride), which increase the natural greenhouse effect, are considered to be the main causes of changes in the Earth's climate system. These gases allow sunlight to pass through but partially block infrared heat radiation emitted from the Earth's surface. In recent decades, the greenhouse effect has intensified, which leads to heating of the lower parts of the atmosphere, which, in turn, causes changes in climatic and meteorological parameters.

Greenhouse effect. The greenhouse effect is understood as an increase in the average temperature of the surface part of the Earth's atmosphere as a result of changes heat balance caused by greenhouse gases. The main greenhouse gases are carbon dioxide and water vapour. The contribution of carbon dioxide to the greenhouse effect, according to various sources, ranges from 50 to 65%. Other greenhouse gases include methane (20%), nitrogen oxides (5%), etc. An increase in the concentration of greenhouse gases leads to the fact that solar radiation continues to freely penetrate to the earth's surface, and long-wave (infrared) radiation coming from the Earth is absorbed greenhouse gases. As a result, the lower troposphere heats up above normal levels and the overall heat balance of the Earth changes. According to available data, due to greenhouse gases, the average annual air temperature on Earth over the past century has increased by 0.3...0.6 °C.

It is believed that prior to the advent of the industrial age (late 19th century), carbon fluxes between the atmosphere, continents, and oceans were balanced. But over the past 100 years, the amount of carbon dioxide in the atmosphere has increased significantly as a result of anthropogenic inputs (Fig. 16.2). One of their main sources is the burning of fossil fuels, but this process is also accelerating as a result of the development of agriculture and deforestation.

Intensive farming leads to loss of soil carbon. The fixation of carbon dioxide by agricultural plants during photosynthesis does not compensate for its amount released from the soil as a result of plowing. Deforestation leads to additional release of carbon dioxide into the atmosphere when wood is burned. Forests are important carbon accumulators, since forest biomass contains 1.5 times more carbon, and forest humus contains 4 times more carbon than in the entire atmosphere.

The photosynthetic green belt of the Earth and the carbonate system of the ocean maintain a constant level of carbon dioxide in the atmosphere. But the rapidly increasing rates of combustion of fossil fuels and the formation of a large amount of carbon dioxide in the course of the development of civilization on Earth begin to exceed the ability of plants to fully assimilate carbon dioxide in the process of photosynthesis.

Most of the carbon in the atmosphere ends up in the ocean, which contains 50 times more carbon dioxide than the atmosphere, or in plants and soil. The rate at which carbon stocks build up in these terrestrial or oceanic reservoirs depends on many factors. The ocean and atmosphere form the global climate system, and changes in one of these blocks can affect the other. In order to be able to predict the direction of climate change, you need to know the processes of transformation thoroughly. various forms carbon in the ocean, transport of carbon into the deep layers of the water column and its accumulation in bottom sediments.

Most of the carbon in the ocean is stored in deep waters and seabed sediments for a long time. One of the ways in which carbon can be supplied from the surface productive layers of the ocean to the depths of the ocean is through biological pump. This path begins with phytoplankton - single-celled organisms that form the basis of the ocean food chain, absorbing carbon dioxide and nutrients and creating organic matter through photosynthesis. Phytoplankton and the zooplankton that feed on them produce particles of organic matter in the form of dead organisms and waste products.

In the process of respiration of aquatic organisms, part of the bound in organic matter carbon is oxidized to mineral forms (carbon dioxide) in the upper layers of the ocean, which in turn can escape into the atmosphere. Fixed organic carbon in the form of organic particles (bodies of aquatic organisms, products of their secretions in the form of sticky lumps) settles under the influence of gravity into the depths of the ocean, where it either oxidizes or becomes part of the sedimentary organic material. How quickly and to what extent carbon dioxide from the atmosphere enters the depths of the ocean, where it is retained for a long time and where it is excluded from the biogeochemical carbon cycle, depends on the intensity of the functioning of marine ecosystems. The transition of carbon from an inorganic form (carbon dioxide) to an organic one (biomass and detritus), the transformation and transfer of carbon to the depths is called a "biological pump", i.e. a process in which carbon is, as it were, pumped out of the atmosphere and accumulated in the ocean (in water and bottom sediments).

Studies have shown that over the past 100 years, the concentration of carbon dioxide in the atmosphere has increased by 25%, and methane - by 100%. The rapid growth of carbon dioxide and methane in the atmosphere was accompanied by a global increase in temperature. Thus, in the 1980s, the average air temperature in the Northern Hemisphere increased compared to the end of the 19th century. by 0.5 ... 0.6 ° С (Fig. 16.3). According to available forecasts, the average temperature on Earth by 2020-2050. can rise by 1.2...2.5°C compared to the pre-industrial era. Warming can lead to intensive melting of glaciers and an increase in the level of the World Ocean by 0.5 ... 1.5 m over the specified period. As a result, many densely populated coastal areas will be flooded. However, with a general increase in precipitation in the central regions of the continents, the climate may become more arid. For example, in the 1980s and 1990s in Africa and North America catastrophic droughts, which are associated with global warming, have become more frequent.

In recent decades, climate warming and an increase in the number precipitation on the territory of Russia had a significant impact on the hydrological characteristics of water resources. So, in the basins of the Volga, Don and Dnieper rivers, an increase in runoff by 20...40% was observed. The increase in the flow of the Volga was the main factor in the increase in 1978-1995. level of the Caspian Sea by almost 2.5 m. In the regions of the Caspian Sea, more than 320 thousand hectares of land were flooded and taken out of land use.

With climate warming, the risk of dangerous floods is expected to increase in many regions of Russia, where an increase in river flows is predicted. Projected changes in water levels will lead to changes in erosion processes in watersheds and in riverbeds, increasing turbidity and deteriorating water quality.

The climate on Earth has always changed, and there have not been any long periods during which it remained stable. But never before has the climate changed as rapidly as it does today.

In addition to the content of greenhouse gases, there are also such important parameters that actively affect the Earth's climate as the content of water vapor in the atmosphere and the moisture cycle over land. As a result of an increase in the average surface air temperature, the content of water vapor in the Earth's atmosphere increases, which leads to an increase in the greenhouse effect. The moisture cycle over land, which is 99% determined by vegetation, is being disrupted due to the accelerated disappearance of forests on the planet.

At the same time, global warming can also lead to a reverse trend - to regional cooling as a result of changes in the direction of sea currents. Already in the first decades of the XXI century. the warm waters of the Gulf Stream may no longer be a barrier to cold currents coming from the Arctic Ocean (from the Labrador Peninsula). Thus, against the background of general planetary warming, a local cooling in the north of Europe is very likely. The effect of the disappearance of oceanic heating can manifest itself very quickly, and, most importantly, it will be sudden and sharp. The consequences of a possible local cooling against the background of general warming may affect Iceland, Ireland, Great Britain, Scandinavian countries, the Murmansk and Arkhangelsk regions, the Republics of Karelia and Komi, and other adjacent regions of Russia.

The results of human influence on the biosphere. In the modern era, human activity has a huge impact on natural conditions the entire planet. The flora and fauna of the land are especially strongly changed. Many species of animals and plants have been completely destroyed by man, and even more species are under the threat of extinction. It is assumed that more than 120 species and subspecies of mammals and about 150 species of birds have recently disappeared.

Enormous changes have taken place in the vegetation cover on most of the surface of the continents. In vast areas, wild vegetation has been destroyed and replaced by agricultural fields. The forests that have survived to this day are largely secondary, that is, heavily modified as a result of human impact in comparison with the natural vegetation cover. Great changes have also taken place in the vegetation cover of many areas of the steppes and savannahs due to intensive grazing by livestock.

Human impact on the natural vegetation cover has had a significant impact on the process of soil formation in the respective areas and has led to a change in the physical and chemical properties of soils. Soils in agricultural fields have changed even more due to the systematic use of artificial chemical fertilizers and the removal of a significant part of the biomass of growing plants. In many areas, unsustainable tillage has led to increased erosion, resulting in the destruction of the soil cover over large areas.

The influence of human activity on the hydrological regime of the land is rapidly increasing. Stock not only small, but also many major rivers has changed significantly as a result of the creation of hydraulic structures, the withdrawal of water to meet the needs of industry and the urban population, and the irrigation of agricultural fields. The creation of large reservoirs, the area of ​​which in many cases is comparable to the area of ​​large natural lakes, has dramatically changed the regime of evaporation and runoff over vast areas.

The period in the history of the relationship between man and nature from the beginning of the 20th century. and is still characterized by the expansion of its expansion: the settlement of all territories available for habitation, the intensive development of industrial and agricultural production, the discovery and start of operation of new ways of releasing and converting energy (including nuclear energy), the beginning of the exploration of near-Earth space and solar system in general, as well as unprecedented population growth.

The history of human influence on the biosphere shows that technological progress is constantly increasing the possibility of influencing the environment, creating the prerequisites for the emergence of major environmental crises. On the other hand, the same technological progress expands the possibilities of eliminating the deterioration of the natural environment created by man. These two opposite tendencies manifested themselves most clearly in the second half of the 20th century. and are currently ongoing.

Control questions and tasks

1. Describe the main directions of human influence on the biosphere.

2. What is the essence of the modern ecological crisis?

3. List the most important environmental problems of our time.

4. What factors influence global climate change?