Global environmental problems. Global environmental problems Main causes of global environmental problems

The essence of the problem:

The ecological problem arose in the sphere of the relationship of human society with the environment (nature). Recently, the conflict between society and nature has escalated, creating a real threat of irreversible changes in natural systems, undermining natural conditions and the existence of present and future generations of the inhabitants of the planet Earth.

Causes of the environmental problem:

Long-term uncontrolled and not always justified spending of natural resources (mining, industrial deforestation, etc.);

Industrialization of the economy (the emergence of a large number of industries that emit harmful substances into the environment);

Increase in the number of people and their needs, etc.

In industrialized countries environmental problems have a predominantly “industrial character”, and in developing countries they are primarily due to the “overuse of natural resources” (forests, soil cover and other natural resources).

At present, the epicenter of environmental problems is being transferred from developed countries to developing countries due to the fact that a number of hazardous industries are transferred there.

In some areas of the Earth, the conflict between man and nature has become so aggravated that it has reached the level of an ecological crisis.

Environmental problems can be divided into three groups:

1. Degradation environment as a result of irrational nature management (deforestation, soil erosion, arid desertification, etc.).

2. Pollution of the lithosphere, hydrosphere and atmosphere with solid, liquid and gaseous wastes of anthropogenic activity (“photochemical fog” (“smog”) over large industrial agglomerations, “acid rain”, garbage dumps, oil pollution of the world ocean, radioactive pollution of the world ocean as a result of disposal of radioactive waste, etc.).

3. Poisoning the environment with chemicals created during the production process (chemicals, pesticides, freons - destroyers of the ozone layer)

In addition, many environmental problems arise as a result of environmental disasters at industrial enterprises (the disaster at the Chernobyl nuclear power plant in 1986) and in certain areas (forest fires).

Ways to solve the environmental problem:

application of energy-saving and resource-saving technologies;

study of permissible limits of impact on nature and the adoption of protective measures, including prohibitive ones;

the use of environmentally less harmful technologies and industries;

carrying out activities aimed at eliminating the consequences of environmental crises and disasters, restoring disturbed ecosystems;

educational activities aimed at the formation careful attitude to nature, etc.

In the 70s of the 20th century, the UN put forward the slogan "There is only one Earth" and identified the main way to solve the environmental problem - such an organization of production and non-production activities of people that would ensure normal "eco-development", preservation and transformation of the environment in the interests of all mankind and every person.

Ecological problem is one of the global problems of our time. It is closely related to issues of resource scarcity. environmental safety and ecological crisis. One of the ways to solve the environmental problem is the path of "sustainable development", proposed as the main alternative to the development of human civilization.

Global environmental issues

Scientific and technological progress has posed a number of new, very complex problems for humanity, which it has not encountered before at all, or the problems were not so large-scale. Among them, a special place is occupied by the relationship between man and the environment. In the 20th century, nature was under pressure due to a 4-fold increase in population and an 18-fold increase in world production. Scientists say that from about the 1960s and 70s. changes in the environment under the influence of man have become global, i.e. affecting all countries of the world without exception, so they began to be called global. Among them, the most relevant are:

Earth's climate change;
air pollution;
destruction of the ozone layer;
depletion of fresh water and pollution of the oceans;
land pollution, destruction of soil cover;
depletion of biological diversity, etc.

Environmental changes in the 1970s-90s and forecast for

2030 are reflected in table. 1. UN Secretary-General Kofi Annan at the meeting of heads of state and government of UN member states (September 2000) presented the report "We the peoples: the role of the United Nations in the 21st century". The report looks at the priority policy areas facing humanity in the new millennium and emphasizes that "the challenge of securing an environmentally sustainable future for future generations will be one of the most challenging."

Table 1. Environmental changes and expected trends up to 2030

Characteristic	Trend 1970-1990	Scenario 2030
Shrinkage of natural ecosystems	Reducing at a rate of 0.5-1.0% per year on land; by the early 1990s. about 40% of them survived	Continued trend, approaching near-total elimination on land
Consumption of primary biological products	Consumption growth: 40% land-based, 25% global (1985 est.)	Consumption growth: 80-85% onshore, 50-60% global
Change in the concentration of greenhouse gases in the atmosphere	Growth in greenhouse gas concentrations from tenths of a percent to a few percent annually	Growth in concentration, acceleration of growth in the concentration of CO, and CH 4 due to accelerated destruction of biota
Depletion of the ozone layer, the growth of the ozone hole over Antarctica	Depletion of 1-2% per year of the ozone layer, an increase in the area of ozone holes	Continued trend even if CFC emissions are phased out by the year 2000
Reduction in forest area, especially tropical	Reduction at a rate from 117 (1980) to 180 ± 20 thousand km 2 (1989) per year; reforestation refers to deforestation as 1:10	Continuing the trend, reducing the area of forests in the tropics from 18 (1990) to 9-11 million km 2, reducing the area of forests in the temperate zone
desertification	Expansion of the area of deserts (60 thousand km 2 per year), growth of technogenic desertification. toxic deserts	The trend will continue, growth rates are possible due to a decrease in moisture turnover on land and the accumulation of pollutants in soils
land degradation	Increased erosion (24 billion tons annually), reduced fertility, accumulation of pollutants, acidification, salinization	Continued trend, increased erosion and pollution, reduced agricultural land per capita
Ocean level rise	Ocean level rise by 1-2 mm per year	Maintaining the trend, it is possible to accelerate the rise in the level up to 7 mm per year
Natural disasters, man-made accidents	Growth in number by 5-7%, increase in damage by 5-10%, increase in the number of victims by 6-12% per year	Maintaining and strengthening trends
Extinction of species	Rapid extinction of species	Increasing trend towards the destruction of the biosphere
Qualitative depletion of land waters	Volume growth Wastewater, point and area sources of pollution, the number of pollutants and their concentration	Maintaining and increasing trends
Accumulation of pollutants in media and organisms, migration in trophic chains	Growth in the mass and number of pollutants accumulated in media and organisms, growth in the radioactivity of the environment, “chemical bombs”	Persistence of trends and their possible strengthening
Deterioration of the quality of life, the growth of diseases associated with environmental pollution (including genetic ones), the emergence of new diseases	Increasing poverty, food shortages, high infant mortality, high level morbidity, insecurity of clean drinking water in developing countries; an increase in genetic diseases, a high accident rate, an increase in drug consumption, an increase in allergic diseases in developed countries; AIDS pandemic in the world, lowering of the immune status	Continuing trends, growing food shortages, growing diseases associated with environmental disturbances (including genetic ones), expanding the territory of infectious diseases, the emergence of new diseases

Environmental issue

Environment (natural environment, natural environment) called that part of nature with which human society directly interacts in its life and economic activity.

Although the second half of the 20th century This is a time of unprecedented rates of economic growth, however, to an ever greater extent, it will be carried out without proper consideration of the possibilities of the natural environment, permissible economic burdens on it. As a result, the degradation of the natural environment occurs.

Irrational nature management

Deforestation and depletion of land resources can be cited as an example of environmental degradation as a result of unsustainable nature management. The process of deforestation is expressed in the reduction of the area under natural vegetation, and primarily forest. According to some estimates, during the emergence of agriculture and animal husbandry, 62 million km 2 of land were covered with forests, and taking into account shrubs and copses - 75 million km 2, or 56% of its entire surface. As a result of the deforestation that has been going on for 10 thousand years, their area has decreased to 40 million km 2, and the average forest cover to 30%. Today, deforestation continues at an ever faster pace: about 100 thousand hectares are destroyed annually. km 2. Forest areas are disappearing as the plowing of land and pastures expands, and timber harvesting grows. A particularly threatening situation has developed in the tropical forest zone, primarily in countries such as Brazil and the Philippines. Indonesia, Thailand.

As a result of soil degradation processes, about 7 million hectares of fertile lands are annually withdrawn from the world agricultural turnover. The main reasons for this process are growing urbanization, water and wind erosion, as well as chemical (contamination with heavy metals, chemical compounds) and physical (destruction of the soil cover during mining, construction and other works) degradation. The process of soil degradation is especially intense in drylands, which occupy about 6 million km 2 and are most characteristic of Asia and Africa. The main areas of desertification are also located within the arid lands, where, due to the high growth rates of the rural population, overgrazing, deforestation and irrational irrigated agriculture lead to anthropogenic desertification (60 thousand km 2 annually).

Pollution of the natural environment with waste

Another reason for the degradation of the natural environment is its pollution with waste from industrial and non-industrial human activities. These wastes are divided into solid, liquid and gaseous.

The following calculations are indicative. Currently, on average, about 20 tons of raw materials are mined and grown annually per inhabitant of the Earth. At the same time, 50 km 3 of fossil rocks (more than 1000 billion tons) are extracted from the subsoil alone, which, using an energy capacity of 2500 W and 800 tons of water, are converted into 2 tons of the final product, of which 50% is immediately thrown away, the rest goes to the deposited waste.

The structure of solid waste is dominated by industrial and mining waste. In general and per capita, they are especially high in Russia and the USA. Japan. The per capita indicator of municipal solid waste is dominated by the United States, where 800 kg of garbage per inhabitant per year (400 kg per inhabitant of Moscow).

Liquid waste pollutes primarily the hydrosphere, with sewage and oil being the main pollutants here. The total volume of wastewater at the beginning of the XXI century. amounted to about 1860 km 3. To dilute a unit volume of polluted wastewater to a level acceptable for use, an average of 10 to 100 and even 200 units of pure water is required. Asia, North America and Europe account for about 90% of the world's wastewater discharges.

As a result, the degradation of the aquatic environment today has taken on a global character. Approximately 1.3 billion people use only polluted water in their homes, and 2.5 billion experience a chronic lack of fresh water, which causes many epidemic diseases. Due to the pollution of rivers and seas, fishing opportunities are reduced.

Of great concern is the pollution of the atmosphere with dusty and gaseous wastes, the emissions of which are directly related to the combustion of mineral fuels and biomass, as well as mining, construction and other earthworks (2/3 of all emissions occur in the developed countries of the West, including the United States - 120 million tons). Examples of major pollutants are typically particulate matter, sulfur dioxide, nitrogen oxides and carbon monoxide. Every year, about 60 million tons of particulate matter are emitted into the Earth's atmosphere, which contribute to the formation of smog and reduce the transparency of the atmosphere. Sulfur dioxide (100 million tons) and nitrogen oxides (about 70 million tons) are the main sources of acid rain. A large-scale and dangerous aspect of the ecological crisis is the impact on the lower layers of the atmosphere of greenhouse gases, primarily carbon dioxide and methane. Carbon dioxide enters the atmosphere mainly as a result of the combustion of mineral fuels (2/3 of all inputs). The sources of methane emissions into the atmosphere are biomass combustion, some types of agricultural production, gas leakage from oil and gas wells. The international community has decided to reduce carbon dioxide emissions by 20% by 2005 and by 50% by the middle of the 21st century. In the developed countries of the world, relevant laws and regulations have been adopted for this (for example, a special tax on carbon dioxide emissions).

The impoverishment of the gene pool

One aspect of the environmental problem is the reduction of biological diversity. The biological diversity of the Earth is estimated at 10-20 million species, including in the territory former USSR-10-12% of the total. The damage in this area is already quite tangible. This is due to the destruction of the habitat of plants and animals, the overexploitation of agricultural resources, environmental pollution. According to American scientists, over the past 200 years, about 900 thousand species of plants and animals have disappeared on Earth. In the second half of the XX century. the process of reducing the gene pool has accelerated sharply, and if the current trends continue over the last quarter of a century, the extinction of 1/5 of all species that now inhabit our planet is possible.

Ecological situation in Russia at the beginning of the XXI century.

The ecological situation in our country is determined by two factors: a decrease in environmental protection costs, on the one hand, and a smaller scale of economic activity than before, on the other.

For example, in 2000, almost 21,000 enterprises with emissions into the atmosphere operated in Russia. These emissions (including cars) amounted to more than 85 million tons, of which almost 16 million were without any treatment. For comparison, in the USSR, emissions from stationary sources and road transport in the mid-1980s amounted to. 95 million tons, in Russia in the early 90s - about 60 million tons. The largest air pollutants in modern conditions are the Siberian and Ural federal districts. They accounted for about 54% of total emissions from stationary sources.

According to the State Water Cadastre, in 2000 the total water intake from natural objects will be 86 km 3 (of which more than 67 km 3 was used for household and drinking, industrial needs, irrigation and agricultural water supply). The total volume of discharges of polluted wastewater into surface waters exceeded 20 km3, of which 25% falls on the Central Federal District. In the USSR, this figure was 160 km 3, in Russia in the 90s. — 70 km 3 (40% of them untreated or insufficiently treated).

In 2000, more than 130 million tons of toxic waste were generated in Russia as a whole. Only 38% of the waste was fully used and neutralized. The largest number of them was formed in the Siberian Federal District (31% of the entire RF). If we talk about solid waste in general, then in the USSR about 15 billion tons of them were generated annually, in Russia in the early 90s. — 7 billion tons.

Thus, although in Russia in the 90s. due to the economic crisis, there was a sharp decrease in emissions of all types of waste, the subsequent economic growth leads to an increase in the volume of waste polluting the environment.

The activity of modern man has 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 the limited possibilities of the 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 of 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 the need for agricultural and industrial production and the volume of natural resources involved. These processes lead to an increase in environmental pollution and a negative impact on 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 it.

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.

Despite the fact that the total population of the Earth is increasing, in some countries there is no increase in population or even its decline. 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 peacetime 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 household waste. 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, which, 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 from nuclear power plants, vehicle 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 chemicals leads to the contamination 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, of course, are necessary to replenish the reserves of nutrients in the soil withdrawn 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 pollution in the form of sewage leads to strong bacteriological contamination and leads to the spread of infectious diseases, which creates additional problems in the field of epidemiology.

Chemical pollution of water occurs as a 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 abiotic and biotic factors that operate 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 living in clean water reappear. 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 flows. 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 continent) 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 the world production of 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 out infrared. thermal radiation emitted by 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 in the 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 burning 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, it is necessary to thoroughly know the processes of transformation of various forms of carbon in the ocean, the transfer 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 (the bodies of aquatic organisms, products of their secretions in the form of lumps stuck together) under the action of gravity settles 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 form (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 late XIX in. 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 catastrophic droughts have become more frequent in Africa and North America, which are associated with global warming.

In recent decades, climate warming and an increase in precipitation in Russia have 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 large quantity species is in danger 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. The flow of not only small, but also many large 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 living, the intensive development of industrial and agricultural production, the discovery and start of operation of new ways of releasing and converting energy (including energy atomic nucleus), 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 man-made deterioration of the natural environment. These two opposite tendencies manifested themselves most clearly in the second half of the 20th century. and are currently ongoing.

test 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?

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 environmental crisis. Currently, the population of the planet is particularly acute environmental problems such as atmospheric 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, the flights of jet aircraft in high layers of the atmosphere, nuclear weapons testing, and the reduction of the planet's forest lands. 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, the average temperature on earth 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, "the largest amount of greenhouse gases is generated by the operation of power plants and methane emissions during the extraction and delivery of energy resources, while road transport or the burning of associated petroleum gas in flaring cause relatively little harm to the environment".

Other prerequisites for global warming are overpopulation of the planet, deforestation, ozone depletion and littering. However, not all ecologists place the responsibility for the increase in average annual temperatures entirely on anthropogenic activities. 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 into the 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.

The effects of acid rain

Solutions of sulfuric and nitric acids, aluminum and cobalt compounds contained in polluted precipitation and fog, 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 waters of land 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.

Introduction

Ecology (from Greek. oikos- residence, residence and ...logia), a biological science that studies the organization and functioning of supraorganismal systems at various levels: populations, species, biocenoses (communities), ecosystems, biogeocenoses and the biosphere. Often uh Cology is also defined as the science of the relationship of organisms with each other and with the environment. Modern uh Cology also intensively studies the problems of interaction between man and the biosphere.

The growth of attention to the problems that have traditionally been the subject of study of environmental science, observed in society over the past decades, is quite natural. The successes of natural science in revealing the secrets of the world order made it possible to push the boundaries of the usual ideas about reality, to approach the awareness of the systemic complexity and integrity of the world, created necessary base to clarify and further develop the idea of the place of man in the system of nature. At the same time, the aggravation of the problems of overpopulation of the planet, the depletion of natural resources, the pollution of the human environment with industrial and agricultural waste, the destruction of natural landscapes, and the reduction in species diversity contributed to the growth of public interest in obtaining environmental information. The development of mass communication systems (print media, radio broadcasting, television, Internet) contributed to the growth of public awareness about the state of the environment, the influences exerted on it by people, and their actual and possible consequences. The effect of these circumstances largely led to an increase in social status ecology and environmentalists.

1. Global environmental problems and their causes

1.1 Resource crisis. Land resources: soil

The most important property of the soil is fertility - the ability to ensure the growth and development of plants. Soil is the most important and irreplaceable source of food resources, the main wealth on which people's lives depend. It is the main means of agricultural production and forestry. The soil is also used as a building material in various earthworks.

As noted in the work, the current state of the soil cover is determined primarily by the activities of human society. Although natural forces do not cease to act on the soil, the nature of their influence changes significantly. The author of the work, noting the importance of human influence on the soil, points out that most of the modern cultivated soils have no similarity in the past history of the planet. As a result of the development of human economic activity, soil degradation, its pollution and a change in its chemical composition occur.

Significant land losses are associated with agricultural activities. Repeated plowing of land makes the soil defenseless against natural forces (winds, spring floods), resulting in accelerated wind and water erosion of the soil, its salinization.

The widespread use of fertilizers, poisons to control pests and weeds leads to the accumulation of substances unusual for it in the soil.

Significant damage to natural ecosystems is caused by the process of urbanization. Drainage of wetlands, changes in the hydrological regime of rivers, pollution natural environments, the growing scale of housing and industrial construction is taking huge areas of fertile land out of agricultural circulation.

One of the consequences of the increasing technogenic load is the intense pollution of the soil cover. The main soil pollutants are metals and their compounds, radioactive elements, as well as fertilizers and pesticides used in agriculture. Lead, mercury and their compounds are among the most dangerous chemical soil pollutants.

Among the tasks of nature protection, the most important is the fight against soil erosion. Among the general measures designed to prevent erosion, the work highlights the general anti-erosion protection of the territory, which provides for proper crop rotation, planting protective forest plantations, hydraulic structures and other anti-erosion measures.

1.2 Land resources: minerals

Mineral raw materials play a huge role in the national economy. Minerals provide about 75% of raw materials for the chemical industry, almost all types of transport, various branches of industrial production work on subsoil products. At the same time, the rate of use of mineral reserves continues to grow. Accordingly, with the growth of production, the total reserves of mineral raw materials on Earth inevitably decrease. This circumstance necessitates the protection of the subsoil, a more reasonable, integrated use of mineral wealth.

Non-renewable natural resource should follow the path of rational, economical use. To do this, it is necessary to minimize the loss of raw materials during its extraction, processing and transportation.

Of great importance in the conservation of mineral deposits is the use of secondary raw materials, in particular scrap metal. Among the measures to protect mineral raw materials, mention should be made of their replacement with synthetic materials. A positive effect in the protection of mineral resources can be achieved by increasing the power of machinery and equipment while reducing their size, metal consumption, energy consumption and reducing the cost per unit of the final useful product. Reducing metal consumption and energy costs is at the same time a struggle for the protection of the subsoil.

1 . 3 Energetic resources

The need for energy is one of the basic human needs. About ten percent of the energy needed by a person is provided by food, the rest is industrial energy.

The acceleration of the pace of scientific and technological progress and the development of material production are associated with a significant increase in energy costs. Therefore, the development of energy appears to be one of the most important conditions for the economic growth of modern society.

For a long time, fossil fuels served as the energy base, the reserves of which were steadily declining. Therefore, recently the task of finding new energy sources is one of the most urgent tasks of our time.

Thermal power engineering. The main source of energy in Russia and the countries of the former USSR is thermal energy obtained from the combustion of fossil fuels - coal, oil, gas, peat, oil shale.

Oil, as well as its heavy fractions (fuel oil) are widely used as fuel. However, the prospects for the use of this type of fuel look doubtful for two reasons. First, oil under no circumstances can be classified as an "environmentally friendly" energy source. Secondly, its reserves (including unexplored ones) are limited.

Gas as fuel is also very widely used. Its reserves, although large, are also not unlimited. Today, methods are known for extracting certain chemicals from gas, including hydrogen, which in the future can be used as a universal "clean" fuel that does not give any pollution.

Coal is no less important in thermal energy than oil and gas. It is used as a fuel in the form of coke obtained by heating coal without air to a temperature of 950-1050°C. At present, in our country, a method has been developed for the most complete use of coal by liquefying it.

Hydropower. The energy of hydroelectric power plants is harmless to the environment. However, the construction of reservoirs on the plains in itself is fraught with negative consequences, the most significant of which is the flooding of vast useful (agricultural, etc.) lands.

Atomic and thermonuclear energy. For a long time, the solution to the problem of the energy crisis was associated mainly with the development of nuclear and, in the future, thermonuclear energy, the latter of which, from a modern point of view, has practically inexhaustible fuel resources. It was generally accepted that one of the most important advantages of nuclear energy is its "environmental cleanliness". Indeed, under favorable conditions, nuclear power plants produce significantly less harmful emissions than fossil fuel power plants.

However, in recent decades, the attitude towards this type of energy has changed significantly. Negative assessment of the role nuclear energy in the life of society is primarily associated with fears regarding the consequences of accidents at nuclear facilities, which lead to serious leaks of radioactive materials and production waste. The positions of the nuclear power industry were seriously undermined by the incidents at the Chernobyl nuclear power plant (1986) and at the nuclear power plant in Japan (2011), the consequences of which led to hysteria and fear in the society of even more serious catastrophes possible in the future. Geothermal energy. Heat reserves in the depths of the earth's interior are practically inexhaustible, and its use from the standpoint of environmental protection is very promising. The electricity generated from hot springs is the cheapest compared to other power plants. However, the efficiency of geothermal power plants is low due to the low temperature of the water coming from the bowels to the surface. The exploitation of geothermal waters requires the solution of the issue of discharge and disposal of waste mineralized waters, since they can have a harmful effect on the environment.