Anthropogenic influence on the biosphere. Impact of anthropogenic factors on the biosphere

Branch of the National Educational Institution of Higher Professional Education "Moscow Institute of Entrepreneurship and Law" in Novosibirsk

TEST

Discipline: Ecology and environmental protection

Topic: Biosphere. Anthropogenic impact on the environment

Specialty: economics

Student: Telina E.S.

Record book code: 05751

Teacher: Lyapina O.P.

Novosibirsk

2009

Introduction………………………………………………………………………………......3

I. Biosphere………………………………………………………………………………...4

1. Biosphere as a global ecosystem………………………………...................4

2. Properties of the biosphere………………………………………………………………..5

3. Boundaries and structure of the biosphere……………………………………………………………..7

3.1 Atmosphere……………………………………………………………………...8

3.2 Hydrosphere………………………………………………………………...9

3.3 Lithosphere ……………………………………………………………………10

II. Anthropogenic impact on the environment…………………...................12

1. Impact on the biosphere……………………………………………......12

2. Impact on the atmosphere……………………………………………………….13

3. Impact on the hydrosphere………………………………………………………………………15

4. Impact on the lithosphere………………………………………………………..17

Conclusion………………………………………………………………………………19

References……………………………………………………………………...20

Task No. 2………………………………………………………………………………………...21

Introduction

Man and nature are inseparable from each other and are closely interconnected. For humans, as well as for society as a whole, nature is the environment for life and the only source of resources necessary for existence. Nature and natural resources are the basis on which human society lives and develops, the primary source of satisfying the material and spiritual needs of people. Man is a part of nature and, as a living being, with his elementary life activities has a tangible impact on the natural environment.

Man has always used the environment mainly as a source of resources, but for a very long time his activities did not have a noticeable impact on the biosphere. Only at the end of the last century, changes in the biosphere under the influence of economic activity attracted the attention of scientists. In the first half of this century, these changes increased and have now hit human civilization like an avalanche. Striving to improve his living conditions, a person constantly increases the pace of material production, without thinking about the consequences. With this approach, most of the resources taken from nature are returned to it in the form of waste, often toxic or unsuitable for disposal. This poses a threat to both the existence of the biosphere and man himself.

I . Biosphere

1. The biosphere as a global ecosystem.

The biosphere (from the Greek bios - life, sphaira - ball) is the area of ​​systemic interaction between the living and bone matter of the planet. It represents a global ecosystem - the totality of all biogeocenoses (ecosystems) of our planet. The first ideas about the biosphere as a “region of life” and the outer shell of the Earth were expressed at the beginning of the 19th century. J. Lamarck. In 1875, the Austrian geologist E. Suess first introduced the modern term “biosphere” into the scientific literature, meaning by it the area of ​​​​interaction between the main shells of the Earth: the atmosphere, hydro- and lithosphere, where living organisms are found. The merit of creating the integrity of the doctrine of the biosphere belongs to V.I. Vernadsky. Using these terms, he created the science of “biosphere”, introduced the concept of “living matter” - the totality of all living organisms, and also assigned living organisms the role of the main transformative force of planet Earth, taking into account the activities of organisms not only at the present time, but also in the past. Therefore, the biosphere is the entire space where life exists or has ever existed, that is, where living organisms or the products of their vital activity are found.

Life in the biosphere depends on the flow of energy and the circulation of substances between biotic and abiotic components. The cycles of substances are called biogeochemical cycles. The existence of these cycles is ensured by the energy of the Sun. Food chains provide a visual representation of the pathways of energy. Each link is a specific trophic level. The first trophic level is occupied by autotrophs, or producers. Organisms of the second trophic level are called primary consumers, the third - secondary consumers, etc. Producers are plants, cyanobacteria (blue-green “algae”) and some other types of bacteria. Part of the energy bound by producers during the process of photosynthesis is consumed during their own respiration, the other part is stored in their cells and tissues and is available to consumers. Organisms that are not capable of photosynthesis or chemosynthesis are heterotrophs, or consumers. These include animals, fungi, most bacteria and a few plants that have lost the ability to photosynthesize. Consumers depend directly (herbivores) or indirectly (carnivores) on the amount of net primary production as a source of energy and substances. The passage of energy through living matter is a path from light to producers, then to consumers, and from both to heat. This path is a flow, not a cycle, because the energy is dissipated as heat into the environment and cannot be used again for photosynthesis. Thus, the energy flow through living matter is a process of loss of energy accumulated by organisms. Maintaining a dynamic balance between the biotic and abiotic components of the biosphere is a necessary condition for the existence of all forms of life. Human impact on the biosphere, accompanied by deterioration of water quality, deforestation, or the release of pollutants into the atmosphere, can pose a threat to life on Earth.

2. Properties of the biosphere.

The biosphere, like other lower-ranking ecosystems that make it up, is characterized by a system of properties that ensure its functioning, self-regulation, stability and other parameters. Let's look at the main ones.

· The biosphere is a centralized system. Its central element is living organisms (living matter). This property is fully disclosed by V.I. Vernadsky, but, unfortunately, is often underestimated by man even today: only one species is placed at the center of the biosphere or its links - man (anthropocentrism).

· The biosphere is an open system. Its existence is unthinkable without the supply of energy from outside. It experiences the influence of cosmic forces, primarily solar activity. For the first time, ideas about the influence of solar activity on living organisms (heliobiology) were developed by A. L. Chizhevsky (1897-1964), who showed that many phenomena on Earth and in the biosphere are closely related to solar activity.

· The biosphere is a self-regulating system, for which, as noted by V.I. Vernadsky, characteristic organization. Currently, this property is called homeostasis, meaning the ability to return to its original state and suppress emerging disturbances by turning on a number of mechanisms. Homeostatic mechanisms are associated mainly with living matter, its properties and functions discussed above.

· The biosphere is a system characterized by great diversity. Diversity is the most important property of all ecosystems. The biosphere as a global ecosystem is characterized by the greatest diversity among other systems. The latter is due to many reasons and factors. These are different living environments (water, land-air, soil, organism); and a variety of natural zones differing in climatic, hydrological, soil, biotic and other properties; and the presence of regions differing in chemical composition (geochemical provinces); and, most importantly, the unification within the biosphere of a large number of elementary ecosystems with their characteristic species diversity.

An important property of the biosphere is the presence in it of mechanisms that ensure the circulation of substances and the associated inexhaustibility of individual chemical elements and their compounds. In the absence of a cycle, for example, in a short time the main “building material” of life would be exhausted - carbon, which is practically the only one capable of forming interelement (carbon) bonds and creating a huge number of organic compounds. Only thanks to the cycles and the presence of an inexhaustible source of solar energy, the continuity of processes in the biosphere and its potential immortality are ensured.

3. Boundaries and structure of the biosphere.

The boundaries of the neo- and paleobiosphere are different.

Upper limit. In most cases, the ozone layer is indicated as the upper theoretical boundary of the biosphere without specifying its boundaries, which is quite acceptable if the difference between the neo- and paleobiosphere is not discussed. Otherwise, it should be taken into account that the ozone screen was formed only about 600 million years ago, after which organisms were able to reach land. In practice, the maximum altitude above sea level at which a living organism can exist is limited by the level up to which positive temperatures remain and chlorophyll-containing producing plants can live (6200m in the Himalayas). Above, up to the “snow line,” only spiders, springtails and some mites live, feeding on grains of plant pollen, plant spores, microorganisms and other organic particles carried by the wind. Even higher, living organisms can only be encountered by chance.

Lower limit. The lower limit of the existence of active life is traditionally determined by the ocean floor of 11,022 m (the maximum depth of the Mariana Trench) and the depth of the lithosphere, characterized by a temperature of 100 ° C (about 6000 m, according to ultra-deep drilling data on the Kola Peninsula). Basically, life in the lithosphere is distributed only a few meters deep, limited to the soil layer. However, through individual cracks and caves it spreads over hundreds of meters, reaching depths of 3000-4000 m. Perhaps the limits of the biosphere are much wider, since organisms have been found in the hydrotherms of the ocean floor at depths of about 3000 m at a temperature of 250°C. Theoretically, at depths of 25,000 m relative to sea level, there should be a critical temperature of 460 ° C, at which, at any pressure, water exists only in the form of steam, and therefore life is impossible. Sedimentary rocks, almost all of which have undergone processing by living organisms, define the lower boundary of former biospheres, which, however, does not fall on the continents below the greatest depths of the ocean.

Biosphere, a dynamic planetary ecosystem, in all periods of its evolutionary development, constantly changed under the influence of various natural processes. As a result of long evolution, the biosphere has developed the ability to self-regulate and neutralize negative processes. This was achieved through a complex mechanism of substance circulation.

The main event in the evolution of the biosphere was recognized as the adaptation of organisms to changed external conditions. For many years, natural biota in the form of communities and ecosystems in the required volume served as a guarantor of the dynamic stability of the biosphere.

However, as new technologies emerged, improved and spread (hunting - agricultural culture - industrial revolution), the planetary ecosystem, adapted to the influence of natural factors, increasingly began to experience the influence of new influences unprecedented in strength, power and variety of influences. They are caused by humans, and therefore are called anthropogenic. Under anthropogenic influences understand activities related to the implementation of economic, military, recreational, cultural and other human interests, introducing physical, chemical, biological and other changes to the natural environment.

The famous ecologist B. Commoner (1974) identified five, in his opinion, main types of human intervention in environmental processes:

Simplifying the ecosystem and breaking biological cycles;

Concentration of dissipated energy in the form of thermal pollution;

Increase in toxic waste from chemical production;

Introduction of new species into the ecosystem;

The appearance of genetic changes in plants and animals.

The overwhelming majority of anthropogenic impacts are goal-oriented character, that is, carried out by a person consciously in the name of achieving specific goals.

Violations of the basic life support systems of the biosphere are primarily associated with targeted anthropogenic impacts. By their nature, depth and area of ​​distribution, duration of action and nature of the application, they can be different.

Analysis of the environmental consequences of anthropogenic impacts allows us to divide all types into positive and negative (negative). TO positive Human impacts on the biosphere include the reproduction of natural resources, restoration of groundwater reserves, land reclamation at the site of mineral development and some other activities.

Negative The (negative) human impact on the biosphere is manifested in a wide variety of large-scale actions: deforestation over large areas, depletion of fresh groundwater reserves, salinization and desertification of lands, a sharp reduction in numbers, as well as species of animals and plants, etc.

The main and most common type of negative human impact on the biosphere is pollution. Most environmental situations in the world are somehow related to environmental pollution (acid rain, hazardous waste, etc.). Therefore, we will consider the concept of “pollution” in more detail.

Pollution call the entry into the natural environment of any solid, liquid and gaseous substances, microorganisms or energies (in the form of sounds, noise, radiation) in quantities harmful to human health, animals, the state of plants and ecosystems.

A more detailed description of this concept is given by the famous French scientist F. Ramad: "Pollution is an adverse change in the environment, which is wholly or partly the result of human activity, directly or indirectly changing the distribution of incoming energy, radiation levels, physical and chemical properties of the environment and the conditions of existence of living beings. These changes can affect humans directly or through agricultural products, water or other biological products (substances).”

By objects of pollution there are distinguished surface contamination And groundwater, air pollution, soil pollution etc. In recent years, problems have also become relevant, associated with pollution of near-Earth space.

Sources anthropogenic pollution, The most dangerous for populations of any organisms are industrial enterprises (chemical, metallurgical, pulp and paper, construction materials, etc.), thermal power engineering, transport, agricultural production and other technologies. Under the influence of urbanization, the territories of large cities and industrial agglomerations are polluted. Natural pollutants There may be dust storms, volcanic ash, mudflows, etc.

By type of pollution they distinguish chemical, physical and biological pollution (Fig. 10.1). In terms of its scale and distribution, pollution can be local, regional and global.

The number of pollutants in the world is enormous, and their number is constantly growing as new technological processes develop. In this regard, scientists give “priority”, both locally and globally, to the following pollutants:

- sulfur dioxide(taking into account the effects of leaching of sulfur dioxide from the atmosphere and the release of the resulting sulfuric acid and sulfates on vegetation, soil and water bodies);

- heavy metals: primarily lead, cadmium and especially mercury (taking into account its migration and transformation into highly toxic methylmercury);

Some carcinogenic substances, in particular benzo(a)pyrene;

- oil and petroleum products in the seas and oceans;

Organochlorine pesticides(in rural areas);

- carbon monoxide and nitrogen oxides(in cities).

Types of pollution also mean any anthropogenic changes undesirable for ecosystems.

ingredient(mineral and organic) pollution as a set of substances alien to natural biogeocenoses (for example,

Rice. 10.1. Types of environmental pollution

household waste, pesticides, combustion products, etc.);

parametric pollution associated with changes in qualitative environmental parameters (thermal, noise, radiation, electromagnetic);

biocenotic pollution that causes disruption in the composition and structure of populations of living organisms (overfishing, acclimatization of species, etc.);

stationary-destructive pollution (station - habitat of a population, destruction - destruction) associated with the disruption and transformation of landscapes and ecosystems in the process of environmental management (regulation of watercourses, urbanization, deforestation, etc.).

It can be noted that the human impact on the biosphere as a whole and on its individual components (atmosphere, hydrosphere, lithosphere and biotic communities) has now reached unprecedented proportions. The current state of planet Earth is assessed as a global environmental crisis. The negative trends of these human impacts on biota are not only pronounced local, but also global in nature.

Municipal educational institution "Tara Gymnasium No. 1"

Abstract
on ecology
on the topic: Anthropogenic impacts on the biosphere.

Completed:
student of grade 9 "A"
Melnikova Yulia

Checked:
Solovyova L.E.

Tara 2009

Municipal educational institution "Tara Gymnasium No. 1" 1

Abstract
on ecology
on the topic: Anthropogenic impacts on the biosphere. 1

Completed:
student of 9th "A" class
Melnikova Yulia 1

Checked:
Solovyova L.E. 1

Tara 2009 1

Introduction 3

1. Current state of the natural environment. 4

2. Atmosphere - the outer shell of the biosphere. Air pollution. 5

3.Water is the basis of life processes in the biosphere. Pollution of natural waters. 7

4. Soil is an important component of the biosphere. Soil pollution. 9

5. Human influence on flora and fauna. 11

6. Radioactive contamination of the biosphere. 12

Conclusion. 13

References: 14

Introduction

Man has always used the environment mainly as a source of resources, but for a very long time his activities did not have a noticeable impact on the biosphere. Only at the end of the last century, changes in the biosphere under the influence of economic activity attracted the attention of scientists. In the first half of this century, these changes increased and have now hit human civilization like an avalanche. Striving to improve his living conditions, a person constantly increases the pace of material production, without thinking about the consequences. With this approach, most of the resources taken from nature are returned to it in the form of waste, often toxic or unsuitable for disposal. This creates a threat to the existence of both the biosphere and man himself.

1. Current state of the natural environment.

Global processes of formation and movement of living matter in the biosphere are connected and accompanied by the circulation of matter and energy. In contrast to purely geological processes, biogeochemical cycles involving living matter have a significantly higher intensity, speed and amount of substance involved in circulation.

With the advent and development of humanity, the process of evolution has changed noticeably. In the early stages of civilization, cutting down and burning forests for agriculture, grazing livestock, fishing and hunting wild animals, and wars devastated entire regions, leading to the destruction of plant communities and the extermination of certain animal species. As civilization developed, especially after the industrial revolution of the end of the Middle Ages, humanity gained ever greater power, an ever greater ability to involve and use huge masses of matter - both organic, living, and mineral, inert - to meet its growing needs.

Real shifts in biosphere processes began in the twentieth century as a result of the next industrial revolution. The rapid development of energy, mechanical engineering, chemistry, and transport has led to the fact that human activity has become comparable in scale to the natural energy and material processes occurring in the biosphere. The intensity of human consumption of energy and material resources is growing in proportion to the population size and even outpacing its growth. V.I. Vernadsky wrote: “Man becomes a geological force capable of changing the face of the Earth.” This warning was prophetically justified. The consequences of anthropogenic (man-made) activities are manifested in the depletion of natural resources, pollution of the biosphere with industrial waste, destruction of natural ecosystems, changes in the structure of the Earth's surface, and climate change. Anthropogenic impacts lead to disruption of almost all natural biogeochemical cycles.

In accordance with population density, the degree of human impact on the environment also changes. At the current level of development of productive forces, the activities of human society affect the biosphere as a whole.

2. Atmosphere - the outer shell of the biosphere. Air pollution.

The mass of our planet's atmosphere is negligible - only one millionth the mass of the Earth. However, its role in the natural processes of the biosphere is enormous: it determines the general thermal regime of the surface of our planet, protects it from harmful influences and ultraviolet radiation. Atmospheric circulation influences local climatic conditions, and through them - the regime of rivers, soil and vegetation cover, and relief formation processes.

The current composition of the atmosphere is the result of the long historical development of the globe. Composition of the atmosphere: - oxygen, nitrogen, argon, carbon dioxide and inert gases.

In the process of their activities, people pollute the environment. Over cities and industrial areas in the atmosphere, the concentration of gases increases, which are usually found in very small quantities or completely absent in rural areas. Polluted air is harmful to health. In addition, harmful gases, combining with atmospheric moisture and falling in the form of acid rain, deteriorate the quality of the soil and reduce crop yields.

According to scientists, every year in the world as a result of human activity, 25.5 billion tons of carbon oxides, 190 million tons of sulfur oxides, 65 million tons of nitrogen oxides, 1.4 million tons of freons, organic lead compounds, hydrocarbons, including carcinogenic, large amounts of solid particles (dust, soot, soot).

Global air pollution affects the state of natural ecosystems, especially the green cover of our planet.

Acid rain, caused mainly by sulfur dioxide and nitrogen oxides, causes enormous damage to forest biocenoses. Forests, especially coniferous ones, suffer from them.

The main cause of air pollution is the combustion of natural fuels and metallurgical production. If in the 19th and early 20th centuries, the combustion products of coal and liquid fuel entering the environment were almost completely assimilated by the vegetation of the Earth, now the content of combustion products is steadily increasing. A number of pollutants enter the air from stoves, furnaces, and car exhaust pipes. Among them, sulfur dioxide stands out - a poisonous gas, easily soluble in water. The concentration of sulfur dioxide in the atmosphere is especially high in the vicinity of copper smelters. It causes the destruction of chlorophyll, underdevelopment of pollen grains, drying and falling of leaves and needles.

As a result of the combustion of various fuels, about 20 billion tons of carbon dioxide are released into the atmosphere annually. Anthropogenic emissions of carbon dioxide exceed natural ones and currently constitute a large proportion of its quantity, disrupting the transparency of the atmosphere, and, consequently, its heat balance. Half of the carbon dioxide produced by the combustion of fossil fuels is absorbed by the ocean and green plants, while half remains in the air. The carbon dioxide content in the atmosphere is gradually increasing and has increased by more than 10% over the past 100 years. Carbon dioxide prevents thermal radiation into outer space, creating the so-called “greenhouse effect”, i.e. an increase in the average temperature of the atmosphere by several degrees, which can cause the melting of glaciers in the polar regions, an increase in the level of the World Ocean, a change in its salinity and temperature and other adverse effects. Thus, changes in the carbon dioxide content in the atmosphere significantly affect the Earth's climate.

3.Water is the basis of life processes in the biosphere. Pollution of natural waters.

Water is the most abundant inorganic compound on the planet; Water is the basis of all life processes, the only source of oxygen in the main driving process on Earth - photosynthesis.

With the advent of life on Earth, the water cycle became relatively complex, because... to the simple phenomenon of evaporation were added more complex processes associated with the vital activity of living organisms, especially humans.

The use of water resources is increasing rapidly. This is due to population growth and improvement of sanitary and hygienic conditions of human life, the development of industry and irrigated agriculture. Daily water consumption for household needs in rural areas is 50 liters per person, in cities - 150 liters. Huge amounts of water are used in industry. To smelt 1 ton of steel, 200 m 3 is required. To produce 1 ton of paper, 100 m3 is required, to produce 1 ton of synthetic fiber - from 2500 to 5000 m3. Industry absorbs 85% of all water consumed in cities, leaving about 15% for domestic purposes.

Even more water is needed for irrigation. During the year, 12-14 m3 of water is consumed per 1 hectare of irrigated land. In our country, more than 150 km 3 is spent annually on irrigation, while about 50 km 3 is spent on all other needs.

If consumption continues at this rate, and taking into account population growth and production volumes, by 2100 humanity may exhaust all fresh water reserves.

The constant increase in water consumption on the planet leads to the danger of “water famine”, which necessitates the development of measures for the cost-effective use of water resources. In addition to the high level of consumption, water shortages are caused by its growing pollution due to the discharge of industrial waste into rivers, especially chemical production and communication wastewater. Bacterial pollution and toxic chemicals (for example, phenol) lead to the death of water bodies. Harmful substances entering waters: oil, oil products (as a result of oil production, transportation, refining, use of oil as fuel and industrial raw materials), toxic synthetic substances (used in industry, transport, public utilities), metals (mercury , lead, zinc, copper, chromium, tin, manganese). The rafting of timber along rivers, which is often accompanied by congestion, also has harmful consequences.

Rivers and lakes also receive mineral fertilizers washed out of the soil by rain - nitrates and phosphates, which in high concentrations can dramatically change the appearance and composition of water bodies, as well as various pesticides - pesticides used in agriculture to control insect pests.

One type of pollution is thermal pollution (power plants and industrial enterprises often discharge heated water into a reservoir, which reduces the amount of oxygen, increases the toxicity of impurities, and disrupts biological balance). The discharge of warm water by enterprises is an unfavorable factor for aerobic organisms living in fresh waters. Oxygen is poorly soluble in warm water, and its deficiency in some places leads to the death of many organisms.

Pollution of the World Ocean.
The waters of the seas and oceans are subject to significant pollution. With river runoff, as well as from sea transport, pathogenic waste, oil products, salts of heavy metals, toxic organic compounds, including pesticides, enter the seas. DDT has even been found in the bodies of penguins living in Antarctica. Pollution of the seas and oceans reaches such proportions that in some cases, caught fish and shellfish are unfit for consumption.

4. Soil is an important component of the biosphere. Soil pollution.

Soil is the top layer of land, formed under the influence of plants, animals, microorganisms and climate from the parent rocks on which it is located. This is an important and complex component of the biosphere, closely connected with its other parts.

Under normal natural conditions, all processes occurring in the soil are in balance. But often people are to blame for disturbing the equilibrium state of the soil. As a result of the development of human economic activity, pollution occurs, changes in the composition of the soil and even its destruction.

The fertile layer of soil takes a very long time to form. At the same time, tens of millions of tons of nitrogen, potassium, and phosphorus - the main components of plant nutrition - are removed from the soil every year along with the harvest. The main factor of soil fertility - humus (humus) is contained in chernozems in an amount of less than 5% of the mass of the arable layer. On poor soils there is even less humus. In the absence of replenishment of soils with nitrogen compounds, its supply can be used up in 50-100 years. This does not happen, since farming involves the introduction of organic and inorganic (mineral) fertilizers into the soil.

Nitrogen fertilizers applied to the soil are used by plants by 40-50%. The rest (about 20%) is reduced by microorganisms to gaseous substances - N 2, N 2 0 - and volatilizes in the atmosphere or is washed out of the soil. Thus, mineral nitrogen fertilizers do not have a long-term effect and therefore have to be applied annually. Unfavorable changes in the soil also occur as a result of incorrect crop rotations, i.e. annual sowing of the same crops, for example, potatoes. The inclusion of legumes in crop rotation enriches the soil with nitrogen. Clover and alfalfa crops, due to the binding of N2 by symbiotic nodule bacteria, make it possible to retain up to 300 kg of nitrogen per 1 ha in the soil. Crop rotations are also necessary to combat herbivorous nematodes, which significantly reduce crop yields. For example, bulb garlic nematodes can reduce onion yields by 50%.

Soil contamination with mercury (with pesticides and waste from industrial enterprises), lead (from lead smelting and from vehicles), iron, copper, zinc, manganese, nickel, aluminum and other metals (near large centers of ferrous and non-ferrous metallurgy), radioactive elements ( as a result of fallout from atomic explosions or during the removal of liquid and solid waste from industrial enterprises, nuclear power plants or research institutes related to the study and use of atomic energy), persistent organic compounds used as pesticides. They accumulate in soil and water and, most importantly, are included in ecological food chains: they pass from soil and water to plants, animals, and ultimately enter the human body with food. Inept and uncontrolled use of any fertilizers and pesticides leads to disruption of the cycle of substances in the biosphere.

Anthropogenic soil changes include erosion(from the Latin “erosion” - to corrode). Destruction of forests and natural grass cover, repeated plowing of the land without following the rules of agricultural technology lead to soil erosion - destruction and washing away of the fertile layer by water and wind. Water erosion is widespread and most destructive. It occurs on slopes and develops due to improper cultivation of the land. Together with melt and rainwater, millions of tons of soil are carried away from fields into rivers and seas every year.

Wind erosion is most pronounced in the southern steppe regions of our country. It occurs in areas with dry, bare soil and sparse vegetation cover. Excessive grazing in steppes and semi-deserts contributes to wind erosion and rapid destruction of grass cover. It takes 250-300 years to restore a 1 cm thick layer of soil under natural conditions.

Significant territories with formed soils are withdrawn from agricultural use due to the open-pit mining method for minerals lying at shallow depths.

5. Human influence on flora and fauna.

Human impact on wildlife consists of direct influence and indirect changes in the natural environment. One form of direct impact on plants and animals is forest cutting. Finding themselves suddenly in open habitat conditions, plants in the lower tiers of the forest experience the adverse effects of direct solar radiation. In heat-loving plants of herbaceous and shrub layers, chlorophyll is destroyed, growth is inhibited, and some species disappear. Light-loving plants that are resistant to elevated temperatures and lack of moisture settle in cleared areas. The animal world is also changing: species associated with the tree stand disappear or migrate to other places.

Mass visits to forests by vacationers and tourists have a noticeable impact on the state of vegetation. In these cases, the harmful effect is trampling, compaction of the soil and its contamination. woody plants dry out. The direct influence of man on the animal world is the extermination of species that provide him with food or other material benefits.

It is believed that since 1600, humans have exterminated more than 160 species and subspecies of birds, and at least 100 species of mammals. The long list of extinct species includes the aurochs, a wild bull that lived in Europe. In the 18th century, the SV described by the Russian naturalist was exterminated. The Steller sea cow is an aquatic mammal belonging to the sirenidae category. A little over 100 years ago, the wild Tarpan horse, which lived in southern Russia, disappeared. Many animal species are on the verge of extinction or are preserved only in nature reserves. Such is the fate of bison, tens of millions of whom inhabited the prairies of North America, and bison, formerly widespread in the forests of Europe. In the Far East, sika deer have been almost completely exterminated. Intensified fishing for cetaceans has brought several species of whales to the brink of destruction: gray, bowhead, and blue. The number of animals is also influenced by human economic activities not related to fishing. The number of Ussuri tiger has sharply decreased as a result of the development of territories within its range and a reduction in the food supply. . Several tens of thousands of dolphins die every year in the Pacific Ocean: during the fishing season, they get caught in nets and cannot get out of them.

The disappearance of a relatively small number of animal and plant species may not seem very significant. However, the main value of living species does not lie in their sole meaning.

Each species occupies a certain place in the biocenosis, in the food chain, and no one can replace it. The extinction of one species or another leads to
reducing the stability of biocenoses.

6. Radioactive contamination of the biosphere.

The problem of radioactive contamination arose in 1945 after the explosion of atomic bombs dropped on the Japanese cities of Hiroshima and Nagasaki. Nuclear weapons tests carried out in the atmosphere have caused global radioactive contamination. Radioactive contamination has a significant difference from others. Radioactive nuclides are nuclei of unstable chemical elements that emit charged particles and short-wave electromagnetic radiation. It is these particles and radiation that enter the human body that destroy cells, as a result of which various diseases can arise, including radiation. When an atomic bomb explodes, very strong ionizing radiation is generated; radioactive particles are scattered over long distances, contaminating the soil, water bodies, and living organisms. Many radioactive isotopes have long half-lives, remaining dangerous throughout their existence. All these isotopes are included in the cycle of substances, enter living organisms and have a detrimental effect on cells. Strontium is very dangerous due to its proximity to calcium. Accumulating in the bones of the skeleton, it serves as a constant source of radiation to the body. Radioactive cesium (137 Cs) is similar to potassium and is abundant in the muscles of affected animals. Studies have shown that the bodies of Alaskan Eskimos who eat reindeer meat contain significant amounts of cesium.

Negligence in the storage and transportation of radiation elements leads to serious radiation contamination.

During a nuclear explosion, a huge amount of fine dust is formed, which remains in the atmosphere for a long time and absorbs a significant part of solar radiation. Scientists' calculations show that even with limited, local use of nuclear weapons, the resulting dust will block most of the solar radiation. There will be a long-term cooling (“nuclear winter”), which will inevitably lead to the death of all life on Earth.

Conclusion.

Environmental problems of the biosphere are very relevant in our time: the greenhouse effect, depletion of the ozone layer, mass deforestation, which disrupts the process of oxygen and carbon cycling in the biosphere, industrial and agricultural waste, the extermination of certain animal species, energy production (hydroelectric power plants cause damage to nature and people - flooding of vast territories under reservoirs, insurmountable obstacles on the migration routes of anadromous and semi-anadromous fish that rise to spawn in the upper reaches of rivers, stagnation of water, slowdown in flow, which affects the life of all living creatures living in the river and near the river; the local increase in water affects; on the soil of the reservoir, leads to flooding, waterlogging, bank erosion and landslides; there is a danger from dams in areas with high seismicity). All this leads to a global environmental crisis and requires an immediate transition to rational environmental management.

Biosphere. Scope and consequences. Global processes of formation and movement of living matter in biosphere connected... the Earth's surface, climate change. Anthropogenic impact lead to violation of almost everyone...

The biosphere, as a global ecosystem, has changed during all periods of its evolution under the influence of various natural processes. As a result of long-term evolution, the biosphere has developed the ability to self-regulate and neutralize the consequences of negative processes. This was achieved through the mechanism of substance circulation. The main stabilizing quality of the biosphere was the ability of organisms to adapt to changes in external conditions by changing intraspecific genetic information, which was formed in the process of evolution.

With the emergence, improvement and spread of new technologies such as hunting, agriculture, industry, the planetary ecosystem, adapted to the influence of natural factors, increasingly began to be influenced by new powerful and diverse factors. They are caused by human activity, and therefore are called anthropogenic.

There are five main types of human intervention in environmental processes:

1. Simplifying the ecosystem and breaking biological cycles;

2. Thermal pollution of the environment;

3. Increase in discharges of toxic waste from chemical production;

4. Introduction of new species into the ecosystem;

5. The appearance of genetic changes in plant and animal organisms.

The overwhelming majority of anthropogenic impacts are goal-oriented character, i.e. carried out by a person consciously to achieve specific goals. Therefore, it is precisely targeted anthropogenic impacts that disrupt the homeostasis of the biosphere.

The human impact on the biosphere can be positive. Positive impacts include the reproduction of natural resources, protective afforestation, land reclamation at the site of mining, etc.

Negative are such types of human impact on the biosphere as deforestation over large areas, depletion of fresh groundwater reserves, salinization and desertification of lands, a sharp reduction in population numbers, and sometimes the complete disappearance of individual biological species, etc.

Pollution in ecology they call the entry into the natural environment of any solid, liquid or gaseous substances, microorganisms or portions of energy (in the form of noise, radiation), etc. in quantities dangerous to human health, animals, the condition of plants and ecosystems in general.

Based on the objects of pollution, they distinguish between pollution of surface and groundwater, atmospheric air pollution, soil pollution, etc. In recent years, problems associated with pollution of near-Earth space have also become relevant.

Sources of anthropogenic pollution are industrial enterprises (chemical, metallurgical, pulp and paper, construction materials, etc.), heat and power engineering, transport, agriculture and other technologies. Under the influence of urbanization, the territories of large cities and industrial agglomerations are most polluted.

By type of pollution they distinguish chemical, physical And biological pollution. In terms of scale and distribution, pollution can be local, regional And global.

The most important substances in terms of the consequences of pollution, both locally and globally, are the following:

Sulfur dioxide SO 2 (taking into account fallout from the atmosphere and the ingress of resulting sulfuric acid and sulfates onto vegetation, soil and water bodies);

Heavy metals (lead, cadmium, mercury);

Carcinogenic substances (benzopyrene);

Oil and petroleum products (especially in the seas and oceans);

Organochlorine pesticides (in rural areas);

Carbon and nitrogen oxides (in cities);

Radioactive substances;

Dioxins (dangerous pollutants from the class of chlorinated hydrocarbons).

MINISTRY OF EDUCATION OF THE RUSSIAN FEDERATION

PUBLIC EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

"KUZBASS STATE TECHNICAL UNIVERSITY"

Department of Chemical Technology of Solid Fuel and Ecology

TEST

By discipline

"Ecology"

Completed by: group student

OPz-08 Vasiliev S. S.

Checked:

Kemerovo, 2009

Introduction

2.1 Air pollution

2.2 Soil pollution

2.3 Pollution of natural waters

Conclusion

Literature used

Introduction

Man has always used the environment mainly as a source of resources, but for a very long time his activities did not have a noticeable impact on the biosphere. Only at the end of the last century, changes in the biosphere under the influence of economic activity attracted the attention of scientists. In the first half of this century, these changes have been increasing and have now hit human civilization like an avalanche. In an effort to improve his living conditions, a person constantly increases the pace of material production, without thinking about the consequences. With this approach, most of the resources taken from nature are returned to it in the form of waste, often toxic or unsuitable for disposal. This poses a threat to the existence of the biosphere and man himself. The purpose of the abstract is to highlight: the current state of the natural environment; characterize the main sources of biosphere pollution; identify ways to protect the environment from pollution.

1. Current state of the natural environment

Let us consider some features of the current state of the biosphere and the processes occurring in it.

Global processes of formation and movement of living matter in the biosphere are connected and accompanied by the circulation of huge masses of matter and energy. In contrast to purely geological processes, biogeochemical cycles involving living matter have a significantly higher intensity, speed and amount of substance involved in circulation.

With the advent and development of humanity, the process of evolution has changed noticeably. In the early stages of civilization, cutting down and burning forests for agriculture, grazing livestock, fishing and hunting wild animals, and wars devastated entire regions, leading to the destruction of plant communities and the extermination of certain animal species. As civilization developed, especially rapidly after the industrial revolution of the end of the Middle Ages, humanity gained greater power, an increasing ability to involve and use huge masses of matter - both organic, living, and mineral, inert - to meet its growing needs.

Population growth and the expanding development of agriculture, industry, construction, and transport caused massive destruction of forests in Europe and North America. Livestock grazing on a large scale led to the death of forests and grass cover, erosion (destruction) of the soil layer (Central Asia, North Africa, southern Europe and the USA). Dozens of animal species have been exterminated in Europe, America, and Africa.

Scientists suggest that the depletion of soils in the territory of the ancient Central American Mayan state as a result of slash-and-burn agriculture was one of the reasons for the death of this highly developed civilization. Similarly, in ancient Greece, vast forests disappeared as a result of deforestation and excessive grazing. This increased soil erosion and led to the destruction of soil cover on many mountain slopes, increased the aridity of the climate and worsened agricultural conditions.

The construction and operation of industrial enterprises and mining have led to serious disturbances of natural landscapes, pollution of soil, water, and air with various wastes.

Real shifts in biosphere processes began in the 20th century as a result of the next industrial revolution. The rapid development of energy, mechanical engineering, chemistry, and transport has led to the fact that human activity has become comparable in scale to the natural energy and material processes occurring in the biosphere. The intensity of human consumption of energy and material resources is growing in proportion to the population size and even outpacing its growth.

Warning about the possible consequences of man's expanding invasion of nature, half a century ago, Academician V.I. Vernadsky wrote: “Man is becoming a geological force capable of changing the face of the Earth.” This warning was prophetically justified. The consequences of anthropogenic (man-made) activities are manifested in the depletion of natural resources, pollution of the biosphere with industrial waste, destruction of natural ecosystems, changes in the structure of the Earth's surface, and climate change. Anthropogenic impacts lead to disruption of almost all natural biogeochemical cycles.

As a result of the combustion of various fuels, about 20 billion tons of carbon dioxide are released into the atmosphere annually and a corresponding amount of oxygen is absorbed. The natural reserve of CO2 in the atmosphere is about 50,000 billion tons. This value fluctuates and depends, in particular, on volcanic activity. However, anthropogenic emissions of carbon dioxide exceed natural ones and currently constitute a large share of its total amount. An increase in the concentration of carbon dioxide in the atmosphere, accompanied by an increase in the amount of aerosol (small particles of dust, soot, suspensions of solutions of certain chemical compounds), can lead to noticeable climate changes and, accordingly, to a disruption of the equilibrium relationships that have developed over millions of years in the biosphere.

The result of a violation of the transparency of the atmosphere, and, consequently, the thermal balance, may result in the occurrence of a “greenhouse effect”, that is, an increase in the average temperature of the atmosphere by several degrees. This can cause the melting of glaciers in the polar regions, an increase in the level of the World Ocean, changes in its salinity, temperature, global climate disturbances, flooding of coastal lowlands and many other adverse consequences.

The release of industrial gases into the atmosphere, including compounds such as carbon monoxide CO (carbon monoxide), oxides of nitrogen, sulfur, ammonia and other pollutants, leads to inhibition of the vital activity of plants and animals, metabolic disorders, poisoning and death of living organisms.

Uncontrolled influence on the climate combined with irrational agricultural practices can lead to a significant decrease in soil fertility and large fluctuations in crop yields. According to UN experts, in recent years fluctuations in agricultural production have exceeded 1%. But a decrease in food production by even 1% can lead to the death of tens of millions of people from starvation.

Forests on our planet are catastrophically declining; irrational deforestation and fires have led to the fact that in many places that were once completely covered with forests, to date they have survived only on 10-30% of the territory. The area of ​​tropical forests in Africa has decreased by 70%, in South America by 60%, in China only 8% of the territory is covered with forest.

1.1 Environmental pollution

The appearance of new components in the natural environment caused by human activity or any major natural phenomena (for example, volcanic activity) is characterized by the term pollution. In general, pollution is the presence in the environment of harmful substances that disrupt the functioning of ecological systems or their individual elements and reduce the quality environment from the point of view of human habitation or economic activity. This term characterizes all bodies, substances, phenomena, processes that in a given place, but not at the time and not in the quantity that is natural for nature, appear in the environment and can bring the system out of equilibrium.

The environmental effects of polluting agents can manifest themselves in different ways; it can affect either individual organisms (manifest at the organismal level), or populations, biocenoses, ecosystems and even the biosphere as a whole.

At the organismal level, there may be a violation of certain physiological functions of organisms, changes in their behavior, a decrease in the rate of growth and development, a decrease in resistance to the influence of other unfavorable environmental factors.

At the population level, pollution can cause changes in their numbers and biomass, fertility, mortality, changes in structure, annual migration cycles and a number of other functional properties.

At the biocenotic level, pollution affects the structure and functions of communities. The same pollutants have different effects on different components of communities. Accordingly, the quantitative relationships in the biocenosis change, up to the complete disappearance of some forms and the appearance of others. The spatial structure of communities changes, chains of decomposition (detritus) begin to predominate over pasture ones, and death - over production. Ultimately, degradation of ecosystems occurs, their deterioration as elements of the human environment, a decrease in their positive role in the formation of the biosphere, and depreciation in economic terms.

There are natural and anthropogenic pollution. Natural pollution occurs as a result of natural causes - volcanic eruptions, earthquakes, catastrophic floods and fires. Anthropogenic pollution is the result of human activity.

Currently, the total power of anthropogenic pollution sources in many cases exceeds the power of natural ones. Thus, natural sources of nitrogen oxide emit 30 million tons of nitrogen per year, anthropogenic ones - 35-50 million tons; sulfur dioxide, respectively, about 30 million tons, more than 150 million tons. As a result of human activity, lead enters the biosphere almost 10 times more than through natural pollution.

Pollutants resulting from human economic activity and their impact on the environment are very diverse. These include: compounds of carbon, sulfur, nitrogen, heavy metals, various organic substances, artificially created materials, radioactive elements and much more.

Thus, according to experts, about 10 million tons of oil enter the ocean annually. Oil on water forms a thin film that prevents gas exchange between water and air. As oil settles to the bottom, it ends up in bottom sediments, where it disrupts the natural processes of the life of bottom animals and microorganisms. In addition to oil, there has been a significant increase in the release of domestic and industrial wastewater into the ocean, containing, in particular, such dangerous pollutants as lead, mercury, and arsenic, which have a strong toxic effect. Background concentrations of such substances in many places have already been exceeded tens of times.

Each pollutant has a certain negative impact on nature, so their entry into the environment must be strictly controlled. Legislation establishes for each pollutant a maximum permissible discharge (MPD) and a maximum permissible concentration (MP K) in the natural environment.

Maximum permissible discharge (MPD) is the mass of a pollutant emitted by individual sources per unit of time, exceeding which leads to adverse consequences for the environment or is dangerous to human health. Maximum permissible concentration (MPC) is understood as the amount of a harmful substance in the environment that does not have a negative impact on human health or his offspring with permanent or temporary contact with it. Currently, when determining MPCs, not only the degree of influence of pollutants on human health is taken into account, but also their impact on animals, plants, fungi, microorganisms, as well as on the natural community as a whole.

Special environmental monitoring (surveillance) services monitor compliance with established MPC and MPC standards for harmful substances. Such services have been created in all regions of the country. Monitoring is especially important in large cities, near chemical plants, nuclear power plants and other industrial facilities. Monitoring services have the right to take measures provided by law, up to the suspension of production and any work, if environmental protection standards are violated.

In addition to environmental pollution, anthropogenic impact is expressed in the depletion of natural resources of the biosphere. The enormous scale of use of natural resources has led to significant changes in landscapes in some regions (for example, in coal basins). If at the dawn of civilization man used only about 20 chemical elements for his needs, at the beginning of the 20th century 60 flowed in, but now more than 100 - almost the entire periodic table. About 100 billion tons of ore, fuel, and mineral fertilizers are mined (extracted from the geosphere) annually.

The rapid growth in demand for fuel, metals, minerals and their extraction has led to the depletion of these resources. Thus, according to experts, if current rates of production and consumption are maintained, proven oil reserves will be depleted in 30 years, gas - in 50 years, coal - in 200. A similar situation has developed not only with energy resources, but also with metals (depletion of aluminum reserves is expected in 500-600 years, iron - 250 years, zinc - 25 years, lead - 20 years) and mineral resources, such as asbestos, mica, graphite, sulfur.

This is not a complete picture of the environmental situation on our planet at the present time. Even individual successes in environmental protection cannot noticeably change the overall course of the process of the detrimental influence of civilization on the state of the biosphere.

2. The atmosphere is the outer shell of the biosphere

2.1 Air pollution

Various negative changes in the Earth's atmosphere are associated mainly with changes in the concentration of minor components of atmospheric air.

There are two main sources of air pollution: natural and anthropogenic.

Natural sources include volcanoes, dust storms, weathering, forest fires, and decomposition processes of plants and animals.

The main anthropogenic sources of air pollution include enterprises of the fuel and energy complex, transport, and various machine-building enterprises.

In addition to gaseous pollutants, large amounts of particulate matter are released into the atmosphere. This is dust, soot and soot. Pollution of the natural environment with heavy metals poses a great danger. Lead, cadmium, mercury, copper, nickel, zinc, chromium, and vanadium have become almost permanent components of the air in industrial centers. The problem of lead air pollution is particularly acute.

Global air pollution affects the state of natural ecosystems, especially the green cover of our planet. One of the most clear indicators of the state of the biosphere is forests and their health.

Acid rain, caused mainly by sulfur dioxide and nitrogen oxides, causes enormous damage to forest biocenoses. It has been established that coniferous species suffer from acid rain to a greater extent than broad-leaved trees.

In our country alone, the total area of ​​forests affected by industrial emissions has reached 1 million hectares. A significant factor in forest degradation in recent years is environmental pollution with radionuclides. Thus, as a result of the accident at the Chernobyl nuclear power plant, 2.1 million hectares of forests were damaged.

Green spaces in industrial cities, whose atmosphere contains a large number of pollutants, suffer especially hard.

The air environmental problem of depletion of the ozone layer, including the appearance of ozone holes over Antarctica and the Arctic, is associated with the excessive use of freons in production and everyday life.

2.2 Soil pollution

Under normal natural conditions, all processes occurring in the soil are in balance. But often people are to blame for disturbing the equilibrium state of the soil. As a result of the development of human economic activity, pollution occurs, changes in the composition of the soil and even its destruction. Currently, there is less than one hectare of arable land for every inhabitant of our planet. And these small areas continue to shrink due to inept human economic activities.

Huge areas of fertile land are being lost in mining operations and during the construction of enterprises and cities. The destruction of forests and natural grass cover, repeated plowing of the land without following the rules of agricultural technology leads to soil erosion - the destruction and washing away of the fertile layer by water and wind (Fig. 58). Erosion has now become a worldwide evil. It is estimated that over the last century alone, as a result of water and wind erosion, 2 billion fertile lands of active agricultural use have been lost on the planet.

One of the consequences of increased human production activity is intensive soil pollution. The main soil pollutants are metals and their compounds, radioactive elements, as well as fertilizers and pesticides used in agriculture.

The most dangerous soil pollutants include mercury and its compounds. Mercury enters the environment with toxic chemicals and waste from industrial enterprises containing metallic mercury and its various compounds.

Lead contamination of soils is even more widespread and dangerous. It is known that when one ton of lead is smelted, up to 25 kg of lead is released into the environment with waste. Lead compounds are used as additives in gasoline, so motor vehicles are a serious source of lead pollution. Lead is especially high in soils along major highways.

Near large centers of ferrous and non-ferrous metallurgy, soils are contaminated with iron, copper, zinc, manganese, nickel, aluminum and other metals. In many places their concentration is tens of times higher than the maximum permissible concentration.

Radioactive elements can enter the soil and accumulate in it as a result of fallout from atomic explosions or during the disposal of liquid and solid waste from industrial enterprises, nuclear power plants or research institutions related to the study and use of atomic energy. Radioactive substances from soils enter plants, then into animals and humans, and accumulate in them.

Modern agriculture, which widely uses fertilizers and various chemicals to control pests, weeds and plant diseases, has a significant impact on the chemical composition of soils. Currently, the amount of substances involved in the cycle in the process of agricultural activity is approximately the same as in the process of industrial production. At the same time, the production and use of fertilizers and pesticides in agriculture increases every year. Their inept and uncontrolled use leads to disruption of the circulation of substances in the biosphere.

Particularly dangerous are persistent organic compounds used as pesticides. They accumulate in soil, water, and bottom sediments of water bodies. But the most important thing is that they are included in ecological food chains, pass from soil and water to plants, then to animals, and ultimately enter the human body with food.

2.3 Pollution of natural waters

Pollution of water bodies is understood as a decrease in their biosphere functions and economic significance as a result of the entry of harmful substances into them.

One of the main water pollutants is oil and petroleum products. Oil can enter water as a result of natural seeps in areas where it occurs. But the main sources of pollution are associated with human activity: oil production, transportation, refining and use of oil as fuel and industrial raw materials.

Other pollutants include metals (for example, mercury, lead, zinc, copper, chromium, tin, manganese), radioactive elements, pesticides coming from agricultural fields, and runoff from livestock farms. Mercury, lead and their compounds pose a slight danger to the aquatic environment from metals.

Expanded production (without treatment facilities) and the use of pesticides in the fields lead to severe pollution of water bodies with harmful compounds. Pollution of the aquatic environment occurs as a result of the direct introduction of toxic chemicals during the treatment of reservoirs for pest control, the entry into reservoirs of water flowing from the surface of treated agricultural land, when waste from manufacturing enterprises is discharged into reservoirs, as well as as a result of losses during transportation, storage and partly with precipitation.

Along with pesticides, agricultural runoff contains a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields. In addition, large amounts of organic nitrogen and phosphorus compounds come from livestock farms and sewage. An increase in the concentration of nutrients in the soil leads to a disruption of the biological balance in the reservoir.

Initially, the amount of microscopic algae in such a reservoir sharply increases. As the food supply increases, the number of crustaceans, fish and other aquatic organisms increases. Then a huge number of organisms die off. It leads to the consumption of all oxygen reserves contained in the water and the accumulation of hydrogen sulfide. The environment in the water changes so much that it becomes unsuitable for the existence of any form of organisms. The reservoir is gradually “dying.”

One type of water pollution is thermal pollution. Power plants and industrial enterprises often discharge heated water into a reservoir. This leads to an increase in the water temperature in it. As the temperature in the reservoir increases, the amount of oxygen decreases, the toxicity of water pollutants increases, and biological balance is disrupted.

In contaminated water, as the temperature rises, pathogenic microorganisms and viruses begin to rapidly multiply. Once in drinking water, they can cause outbreaks of various diseases.

In a number of regions, groundwater was an important source of fresh water. Previously, they were considered the purest. But currently, as a result of human economic activity, many sources of groundwater are also subject to pollution. Often this contamination is so great that the water from them has become undrinkable.

Humanity consumes a huge amount of fresh water for its needs. Its main consumers are industry and agriculture. The most water-intensive industries are mining, steel, chemicals, petrochemicals, pulp and paper, and food processing. Up to 70% of all water consumed in industry goes to them. The main consumer of fresh water is agriculture: 60-80% of all fresh water is used for its needs.

Already at the present time, not only territories that nature has deprived of water resources are experiencing a lack of fresh water, but also many regions that until recently were considered prosperous in this regard. Currently, the need for fresh water is not met for 20% of the urban and 75% of the rural population of the planet.

Human intervention in natural processes has affected even large rivers (such as the Volga, Don, Dnieper), changing towards a decrease in the volume of transported water masses (river flow). Most of the water used in agriculture is spent on evaporation and the formation of plant biomass and, therefore, is not returned to rivers. Already, in the most populated areas of the country, river flow has decreased by 8%, and in rivers such as the Don, Terek, and Ural - by 11-20%. The fate of the Aral Sea is very dramatic, having essentially ceased to exist due to excessive withdrawal of water from the Syr Darya and Amu Darya rivers for irrigation.

Limited fresh water supplies are further diminished by pollution. The main danger is wastewater (industrial, agricultural and domestic), since a significant part of the used water is returned to water basins in the form of wastewater.

3. Radiation and environmental problems in the biosphere

Radiation contamination is significantly different from others. Radioactive nuclides are nuclei of unstable chemical elements that emit charged particles and short-wave electromagnetic radiation. It is these particles and radiation that enter the human body that destroy cells, which can result in various diseases, including radiation.

There are natural sources of radioactivity everywhere in the biosphere, and humans, like all living organisms, have always been exposed to natural radiation. External irradiation occurs due to radiation of cosmic origin and radioactive nuclides in the environment. Internal radiation is created by radioactive elements entering the human body with air, water and food.

To quantitatively characterize the impact of radiation on humans, units are used - the biological equivalent of a roentgen (rem) or a sievert (Sv): 1 Sv = 100 rem. Since radioactive radiation can cause serious changes in the body, every person should know its acceptable doses.

As a result of internal and external radiation, a person receives an average dose of 0.1 rem over the course of a year and, therefore, about 7 rem over the course of his entire life. At these doses, radiation does not harm humans. However, there are areas where the annual dose is higher than average. For example, people living in high mountain areas can receive a dose several times higher due to cosmic radiation. Large doses of radiation can occur in areas where the content of natural radioactive sources is high. For example, in Brazil (200 km from Sao Paulo) there is a hill where the annual dose is 25 rem. This area is uninhabited.

The greatest danger is posed by radioactive contamination of the biosphere as a result of human activity. Currently, radioactive elements are widely used in various fields. Negligent storage and transportation of these elements leads to serious radioactive contamination. Radioactive contamination of the biosphere is associated, for example, with the testing of atomic weapons.

In the second half of our century, nuclear power plants, icebreakers, and submarines with nuclear installations began to be put into operation. During normal operation of nuclear energy and industrial facilities, environmental pollution with radioactive nuclides is a negligible fraction of the natural background. A different situation arises during accidents at nuclear facilities.

Currently, the problem of warehousing and storing radioactive waste from the military industry and nuclear power plants is becoming increasingly acute. Every year they pose an increasing danger to the environment. Thus, the use of nuclear energy has posed new serious problems for humanity.

Human economic activity, acquiring an increasingly global character, begins to have a very noticeable impact on the processes occurring in the biosphere. You have already learned about some of the results of human activity and their impact on the biosphere. Fortunately, to a certain level the biosphere is capable of self-regulation, which allows us to minimize the negative consequences of human activity. But there is a limit when the biosphere is no longer able to maintain equilibrium. Irreversible processes begin that lead to environmental disasters. Humanity has already encountered them in few regions of the planet.

Humanity has significantly changed the course of a number of processes in the biosphere, including the biochemical cycle and migration of a number of elements. Currently, although slowly, a qualitative and quantitative restructuring of the entire biosphere of the planet is taking place. A number of complex environmental problems in the biosphere have already arisen that need to be resolved in the near future.

"Greenhouse effect". Climate warming can lead to intensive melting of glaciers and rising sea levels. The changes that may occur as a result are simply difficult to predict.

This problem could be solved by reducing carbon dioxide emissions into the atmosphere and establishing balance in the carbon cycle.

Depletion of the ozone layer. In recent years, scientists have become increasingly concerned about the depletion of the ozone layer of the atmosphere, which is a protective shield against ultraviolet radiation. This process occurs especially quickly over the poles of the planet, where so-called ozone holes have appeared. The danger lies in the fact that ultraviolet radiation is destructive to living organisms.

The main reason for the depletion of the ozone layer is the use by people of chlorofluorocarbons (freons), widely used in production and everyday life as refrigerants, foaming agents, and solvents. aerosols. Freons intensively destroy ozone. They themselves deteriorate very slowly, within 50-200 years. In 1990, the world produced more than 1,300 thousand tons of ozone-depleting substances.

Under the influence of ultraviolet radiation, oxygen molecules (O2) break down into free atoms, which in turn can join with other oxygen molecules to form ozone (O3). Free oxygen atoms can also react with ozone molecules to form two oxygen molecules. Thus, an equilibrium is established and maintained between oxygen and ozone.

However, pollutants such as freons catalyze (accelerate) the process of ozone decomposition, disturbing the balance between it and oxygen towards a decrease in ozone concentration.

Given the danger looming over the planet, the international community has taken the first step towards solving this problem. An international agreement has been signed, according to which the production of freons in the world should be reduced by approximately 50% by 1999.

Mass deforestation is one of the most important global environmental problems of our time.

You already know that forest communities play a vital role in the normal functioning of natural ecosystems. They absorb atmospheric pollution of anthropogenic origin, protect the soil from erosion, regulate the normal flow of surface water, prevent a decrease in groundwater levels and siltation of rivers, canals and reservoirs.

A decrease in forest area disrupts the process of oxygen and carbon cycling in the biosphere.

Deforestation entails the death of their richest flora and fauna. Man is depleting the appearance of his planet.

However, it seems that humanity is already aware that its existence on the planet is inextricably linked with the life and well-being of forest ecosystems. The serious warnings of scientists, sounded in declarations of the United Nations and other international organizations, began to resonate. In recent years, work on artificial afforestation and the organization of highly productive forest plantations has begun to be successfully carried out in many countries around the world.

Production waste. Industrial and agricultural waste has become a serious environmental problem. You already know what harm they cause to the environment. Currently, attempts are being made to reduce the amount of waste that pollutes the environment. For this purpose, complex filters are developed and installed, and expensive treatment facilities and settling tanks are built. But practice shows that although they reduce the danger of pollution, they still do not solve the problem. It is known that even with the most advanced treatment, including biological, all dissolved minerals and up to 10% of organic pollutants remain in the treated wastewater. Waters of this quality can only become suitable for consumption after repeated dilution with clean water.

Obviously, a solution to the problem is possible by developing and introducing into production completely new, closed, waste-free technologies. When using them, water will not be discharged, but will be reused in a closed cycle. All by-products will not be thrown away as waste, but will be subject to deep processing. This will create conditions for obtaining additional products that people need and will protect the environment.

Agriculture. In agricultural production, it is important to strictly follow the rules of agricultural technology and monitor fertilizer application rates. Since chemical means of controlling pests and weeds lead to significant disturbances in the ecological balance, ways to overcome this crisis are being sought in several directions.

Work is underway to develop plant varieties that are resistant to agricultural pests and diseases: selective bacterial and viral preparations are being created that affect, for example, only insect pests. Ways and methods of biological control are being sought, that is, a search is underway for hydroelectric power plants and the reproduction of natural enemies that destroy harmful insects. Highly selective drugs are being developed from a number of hormones, antihormones and other substances that can act on the biochemical systems of certain types of insects and do not have a noticeable effect on other types of insects or other organisms.

Energy production. Very complex environmental problems are associated with energy production at thermal power plants. The need for energy is one of the basic life needs of a person. Energy is needed not only for the normal activities of modern, complexly organized human society, but also for the simple physical existence of every human organism. Currently, electricity is mainly obtained from hydroelectric power plants, thermal and nuclear power plants.

At first glance, hydroelectric power plants are environmentally friendly enterprises that do not harm nature. This was the opinion for many decades. In our country, many largest hydroelectric power stations have been built on the great rivers. It has now become clear that this construction has caused great damage to both nature and people.

First of all, the construction of dams on large lowland rivers leads to the flooding of vast areas under reservoirs. This is due to the displacement of large numbers of people and the loss of pasture lands.

Secondly, by blocking the river, the dam creates insurmountable obstacles on the migration routes of anadromous and semi-anadromous fish that rise to spawn in the upper reaches of rivers.

Thirdly, the water in the storage facilities stagnates, its flow slows down, which affects the lives of all living creatures living in the river and Ureki.

Fourthly, local water rise affects groundwater, leading to flooding, waterlogging, coastal erosion and landslides.

This list of negative consequences of the construction of hydroelectric power stations on lowland rivers can be continued. Large high-rise dams on mountain rivers are also sources of danger, especially in areas with high seismicity. In world practice, there are several cases where the breach of such dams led to enormous destruction and the death of hundreds and thousands of people.

From an environmental point of view, nuclear power plants are the cleanest among other currently operating energy complexes. The dangers of radioactive waste are fully recognized, and therefore both the design and operating standards of nuclear power plants provide for reliable isolation from the environment of at least 99.999% of all resulting radioactive waste.

Not everyone knows that coal has little natural radioactivity. Since thermal power plants burn huge volumes of fuel, their total radioactive emissions are higher than those of nuclear power plants. But this factor is secondary in comparison with the main disaster from installing organic fuels on nature and people - emissions of chemical compounds into the atmosphere that are combustion products.

Although nuclear power plants are environmentally cleaner than simple power plants, they pose a greater potential danger in the event of serious reactor accidents. We were convinced of this by the example of the Chernobyl disaster. Thus, the energy sector poses seemingly insoluble environmental problems. The search for a solution to the problem is being carried out in several directions.

Scientists are developing new safe reactors for nuclear power plants. The second direction is related to the use of non-traditional renewable energy sources. This is, first of all, the energy of the Sun and wind, the heat of the earth’s interior, the thermal and mechanical energy of the ocean. In many countries, including ours, not only experimental, but also industrial installations have already been created on these energy sources. They are still relatively low-power. But many scientists believe that they have a great future.

Conclusion

Due to the increasing scale of anthropogenic impact (human economic activity), especially in the last century, the balance in the biosphere is being disrupted, which can lead to irreversible processes and raise the question of the possibility of life on the planet. This is due to the development of industry, energy, transport, agriculture and other types of human activity without taking into account the capabilities of the Earth's biosphere. Already, humanity is facing serious environmental problems that require immediate solutions.

Literature used

1. A. M. Vladimirov, environmental protection / - L.: Gidrometeoizdat, 1991

2. G. A. Bogdanovsky “Chemical ecology” Moscow University Publishing House 1994

3. E. A. Kriksunov, V.V. Pasechnik, A.P. Sidorin “Ecology” Publishing house “Drofa” 2005

4. N.A. Agadzhanyan, V.I. Torshin “Human Ecology” MMP “Ecocenter”, KRUK2004