What are the nine major phenomena of pollution and destruction of the Earth's environment?

Nine phenomena of pollution and destruction of the Earth's environment

Atmospheric pollution

Classification of atmospheric pollutants

Atmospheric pollutants can be divided into two categories, namely, natural pollutants and man-made pollutants, often caused by public health hazards are man-made pollutants, which are mainly from the burning of fuels and large-scale industrial and mining enterprises. Other harmful substances: such as heavy metals, fluorine gas, chlorine gas and so on.

Hazards of atmospheric pollution

The impact of atmospheric pollution on the climate is very large, the pollutants emitted by atmospheric pollution on the local area and the global climate will have a certain impact, especially on the global climate, from a long-term point of view, this impact will be very serious.

The increase in carbon dioxide content in the atmosphere, the fuel contains a variety of complex components, in the combustion of a variety of harmful substances, even if the fuel does not contain impurities to achieve complete combustion, but also to produce water and carbon dioxide, because the fuel combustion of carbon dioxide concentration in the atmosphere continues to increase, destroying the balance of carbon dioxide in the natural world, to the point that may trigger the "greenhouse effect", resulting in the Earth's greenhouse effect. Greenhouse effect", resulting in an increase in the earth's temperature. The second is the destruction of the ozone layer. After the atmosphere has been polluted, due to the different sources, nature and duration of the pollutants, the differences in meteorological conditions and geographic environment of the polluted areas, as well as the different ages and health conditions of human beings, the hazards to the human body are not the same. Harmful substances in the atmosphere mainly through the following three ways to invade the human body to cause harm:

(1) through the human direct breathing into the human body;

(2) attached to food or dissolved in water, so that the diet and invasion of the human body;

(3) through the contact or stimulation of the skin and enter the human body. Among them, through the breath and invade the human body is the main way, also the most harmful.

The harm of air pollution can be roughly divided into acute poisoning, chronic poisoning, carcinogenic three.

Two, acid rain

Some people believe that acid rain is a silent crisis, and is the most serious environmental threat ever to hit us, is an invisible enemy. This is not alarmist talk.

As industrialization and energy consumption increase, so do acidic emissions, which enter the air and through a series of actions form acid rain.

There are controls on acidic emissions, but there is still acid rain. Atmospheric dust may be another cause of the acid rain problem.

Acidic Emissions

In the free atmosphere, water vapor condenses due to the presence of condensation nuclei in the range of 0.1-10 μm, and then grows further through processes such as merging and agglomeration, resulting in the formation of clouds and raindrops. Inside the cloud, the cloud droplets touch each other or aerosol particles, while absorbing gaseous pollutants in the atmosphere, and a chemical reaction occurs inside the cloud droplets, this process is called the removal of pollutants from the cloud or rain. During the descent of raindrops, the raindrops flush the gases and aerosols in the air through which they pass, and chemical reactions also occur within the raindrops, a process called under-cloud removal or flushing of pollutants. These processes are also known as the removal of particulate matter from gaseous substances in the atmosphere by precipitation, and acidification is formed during these processes.

Atmospheric dust

Recent discoveries have shown that acid rain is a much more complex phenomenon than originally thought. The results obtained from the study show that alkali compounds present in the atmosphere unexpectedly play a key role. Alkalis counteract the effects of acid rain by neutralizing acidic pollutants. We found that the fact that alkali emissions have also declined has been obscured by the fact that all the attention has been focused on the acids in the atmosphere. It appears that a number of factors are reducing the amount of these bases in the atmosphere, thus exacerbating the ecological impact of acid rain. Ironically, several of these factors are the very things that governments are doing to improve air quality.

Most of the bases in the atmosphere are found in airborne particles called atmospheric dust. These dust particles are rich in minerals such as calcium carbonate and magnesium carbonate, which act as alkalis when dissolved in water. Atmospheric dust particles are formed from a variety of sources***. Combustion of fuels and industrial activities such as cement production, mining and metal smelting produce alkali containing particles. Construction sites, farms, and vehicle travel on unpaved roads also contribute to dust particles.

Three, ozone layer destruction

The ozone layer is the Earth's best umbrella, which absorbs most of the ultraviolet light from the sun. However, nearly two decades of scientific research and atmospheric observations have revealed that the ozone layer in the Antarctic atmosphere has been thinning every spring, and that there is in fact an ozone "hole" in the polar atmosphere.

Is this phenomenon of ozone depletion an anomaly, and is it a sign that this ultraviolet absorbing layer is in the midst of a global catastrophe? Through ongoing scientific research, it has been found that the ozone layer is being severely damaged by substances released by human activities, but this phenomenon is also influenced by the unique meteorological conditions of the region (polar vortex, cold stratospheric temperatures, polar stratospheric clouds).

Discovery process

Atmospheric scientists from the British Antarctic Survey (BAS) conducted a program of research in the Antarctic, both on the ground and in the air. Ball-borne instruments generally examine the composition of the atmosphere in which the instrument is traveling and its chemical properties. Land-based and satellite-based instruments perform telemetry missions. These research activities take an international cooperative approach. For example, in 1987, some 150 scientists and support staff representing 19 organizations and four countries met in Punta Arenas, Chile, to conduct an unprecedented study, the Airborne Antarctic Ozone Experiment (AAOE). The experiment showed that the size of the ozone hole reached an all-time high in 1987. The discovery shocked the scientific community.

Mechanism of formation

The cause of the polar "ozone hole" is still not conclusive, and the most convincing is the pollutant theory. In addition: NASA Hampton Chili Center Callis et al. proposed the destruction of the Antarctic ozone layer and strong solar activity; the Massachusetts Institute of Technology (MIT) Tung et al. that there is a unique atmospheric environment in Antarctica caused by the depletion of ozone in late winter and early spring, according to atmospheric dynamics, pointing out that a large number of hydrochlorofluorocarbon compounds used, as well as Antarctica, the early spring of the lack of sufficient sunlight to produce a large number of oxygen atoms, and therefore the cycle of oxygen atoms is not needed. proposes a cyclic mechanism that does not require oxygen atoms.

Through the analysis, we seem to be able to come up with the following main points: (1) The Antarctic "ozone hole" is a special phenomenon caused by the participation of polar stratospheric clouds and non-homogeneous chemical reactions under the special temperature and circulation conditions in the Antarctic spring. (2) The influence of other factors, such as the polar vortex, on the transportation of gas components is not a determining factor for the formation of the Antarctic "ozone hole", but only affects the intensity of the ozone hole. (3) The influence of solar cycle changes on the strength of the Antarctic "ozone hole" through photochemical reactions can be ignored.

Four, water pollution

Human activities will make a large number of industrial, agricultural and domestic waste discharged into the water, so that water pollution. Definition of "water pollution": the water body due to the intervention of a substance, and lead to its chemical, physical, biological or radiological characteristics of the change, thus affecting the effective use of water, endangering human health or damage to the ecological environment, resulting in the deterioration of water quality phenomenon known as water pollution.

There are two types of water pollution: one is natural pollution; the other is man-made pollution. The current harm to the water body is more man-made pollution. Water pollution can be divided into chemical pollution, physical pollution and biological pollution according to the different impurities of pollution.

1, seawater pollution

Sewage, slag, waste oil and chemical substances constantly flowing into the sea. In many seas it is illegal to dump sewage mixed with oil, but it still happens from time to time, and the real oil disaster occurs when a giant tanker leaks or sinks. Today we try to remove oil by using chemicals to precipitate it in the water.

Dumping chemical and radioactive waste into the ocean has been going on for years. One day the containers will corrode and the hazardous materials will enter the water. We don't know much about the deep water-surface water cycle, and it may be happening faster than we previously thought. Thus harmful substances spread into the layers of water where living things are active.

2. Surface Water Pollution

More than five hundred years ago, people thought it was dangerous to drink from the rivers that flowed through large cities, and industrialization, population growth, and new toxic chemicals have made the situation worse.

The paving of drainage systems and the unabated use of detergents have increased phosphate levels in our waterways and lakes. This over-nutrition leads to rapid algae blooms. Depletion of oxygen in the water kills fish and degrades the ecosystem. Serious water pollution is also caused by the improper disposal of mercury compounds and other heavy metals by industry. Mercury gradually concentrates through the course of the food chain and eventually causes severe neurological damage to birds or humans who eat fish.

3, groundwater pollution

With surface water, groundwater is also threatened by pollution, mainly from the surface or soil water seepage, agricultural nitrogen fertilizers as well as garbage in the oil, phenol contamination of groundwater, nitrogen fertilizers in the nitrate once into the ground, it will be transformed into nitrites, which in the human body can be transformed into a carcinogen. Destruction of ground vegetation and drainage of wetlands reduces infiltration of surface water, thus lowering the diving surface. Further reductions in the diving surface can also occur as a result of excessive urban and industrial demand, where freshwater is continuously pumped out for domestic and industrial use and then re-discharged as surface water effluent. On the other hand, extensive and frequent irrigation can enhance infiltration and raise the submerged surface all the way to the surface. In arid areas, the land infiltrated by water will sooner or later become uncultivable and saline due to the unusual evapotranspiration that causes the precipitation of salts in the groundwater.

Water Conservation

The earth's water seems to be inexhaustible, but in fact, in terms of current human use, only fresh water is the main water resource, and only a small portion of fresh water can be used by people. Fresh water is a renewable resource, and its renewability depends on the Earth's water cycle. With the development of industry and the increase in population, a large number of water bodies have been polluted; in order to extract river water, many countries have built dams in the upper reaches of rivers, which have altered the flow of water, so that the water cycle and self-purification have been seriously affected.

V. Solid Waste

All human activities generated by the process, and the owner no longer has the value of the use of solid or semi-solid substances that are discarded, commonly known as solid waste. Various types of production activities in the solid waste commonly known as slag; living activities in the solid waste is called garbage." The term "solid waste" actually refers only to the original owner. In any production or life process, the owner of raw materials, goods or consumer goods, often only utilized some of the active ingredients, and for the original owner no longer has the value of the majority of solid waste still contains other production industries in the need for ingredients, after a certain technical aspects, can be transformed into the relevant sectors of the industry in the production of raw materials, or even can be used directly. It can be seen that the concept of solid waste at any time, space changes and has a relative nature.

Solid waste generation pathway

Maintaining all the activities of human society materials, in a dynamic equilibrium process, and follow the law of conservation of quality, available social material flow to describe this law.

1. All human activities, relative to the external environment, but the development and utilization of materials, and ultimately in the form of waste equal return to the environment. This material "use and return" is often in a cross state. In the production and consumption of products, all forms of waste are generated, and part of this waste is recycled and reused in production and consumption. The other part, which happens to be equal to the amount of raw materials developed in the environment, returns to the environment in the form of waste, forming a closed loop system.

2. In modern society, every aspect of human activity generates various states of waste, from the development of raw materials in the environment to the utilization of products, without exception. Therefore, the only way to seek to reduce the production of waste is to reduce the development of raw materials and reduce the consumption of raw materials for products.

Categorization of solid waste

The classification of solid waste is based on the pathway and nature of its generation. In economically developed countries, solid waste is divided into four categories: industrial, mining, agricultural solid waste and municipal garbage. China's "Solid Waste Management Law", solid waste is divided into industrial solid waste (slag) and municipal garbage two categories. Which contains toxic and hazardous components, a separate sub-category of toxic and hazardous solid waste.

Hazards of solid waste

Garbage is becoming a major problem plaguing human society, the world to produce more than 1 billion tons of garbage every year, a large number of living and industrial waste due to the lack of treatment systems and open piles, garbage siege phenomenon is becoming increasingly serious, piles of garbage stench, germs breeding, toxic substances contaminate the surface and groundwater, a serious hazard to human health, this phenomenon, if not curbed, human beings will not be able to find a solution to this problem.

This phenomenon, if not curbed, human beings will be buried by their own production of garbage.

Six, ground subsidence

Ground subsidence refers to a certain surface area within the ground level of the phenomenon of lowering. The phenomenon of ground subsidence has been recorded in history for a long time. As a natural disaster, the occurrence of ground subsidence has certain geological reasons. However, with the economic development of human society and the expansion of population, the phenomenon of ground subsidence has become more and more frequent and the area of subsidence has become larger and larger. In densely populated cities, ground subsidence is particularly serious. Now when we study the causes of ground subsidence, it is not difficult to find that man-made factors have greatly exceeded natural factors. Now the phenomenon of ground subsidence rather than a natural disaster, it is better to call it a man-made scourge.

The geological causes of ground settlement

From the geological factors, the natural ground settlement occurs roughly for the following three reasons:

1, the surface of the loose layer or semi-loose layer, etc. under the action of gravity, in the loose layer into a dense, hard or semi-hard rock layer, the ground will be due to the thickness of the stratum of the ground becomes smaller and subsidence occurs.

2. Subsidence occurs when the ground is sunken due to geological structure.

3. Earthquakes cause the ground to settle.

Man-made causes of ground settlement

The phenomenon of ground settlement is closely related to human activities. Especially in recent decades, human over-exploitation of oil, natural gas, solid minerals, groundwater, etc. has directly led to today's global ground subsidence. As all large and medium-sized cities are under enormous population pressure, the over-exploitation of groundwater is even more serious, leading to ground subsidence in most cities, and in coastal areas it has also caused seawater intrusion.

VII. Changes in Biodiversity

Biomes are diverse, and can be divided into several types from different perspectives. The meaning of biodiversity is very broad, that is, including the diversity of biological species, but also includes ecological adaptability, morphology, physiological ecological diversity and other broad content.

Different geographical and climatic environments have different biological communities. With the development of industrial civilization, the gradual expansion of human society has changed the biological environment in a wide range of areas, seriously affecting biodiversity, and species are decreasing from the earth at an unprecedented rate.

It is estimated that thousands of species of plants and animals become extinct every year around the world.

Deforestation

The greatest threat to the world's plants and animals is ecological destruction. It is very difficult for most living things to leave an environment to which it has adapted. One of the most species-rich places in the world is the tropical rainforest area, but it is now being destroyed faster and faster. Virtually all of the world's natural forests are seriously threatened. To the least extent, rainforests have been replaced by monoculture economic forests, and in the worst cases they have been destroyed by erosion into barren scrubland.

The World Conservation Fund (WWF) estimates that forests are disappearing globally at a rate of 2% per year, and that at this rate, people will not see natural forests in 50 years.

Much of North America's grasslands are already more or less gone. In Africa, savannas rich in animal resources are being burned in large numbers as a solution to the problem of feeding a growing population. The use of traditional agricultural methods in arid regions is both unreliable and dangerous. Efforts to reclaim the inland steppes of Central Asia have suffered many unfortunate setbacks.

Drainage Wetlands

Swampy wetlands are not only a living environment for organisms, but also play an important role in the hydrological cycle. It regulates the flow of rivers and improves groundwater recharge. But in order to develop industry and build housing, many wetlands are either drained or filled with water. Attempts to convert wetlands to cropland often result in poor soil and low yields.

Urbanization

Towns and cities developed in good agricultural areas, and urbanization often meant sacrificing arable land for homes, streets, and parking lots. In this way arable land becomes waste land that cannot produce living things. From a natural or economic point of view, it is difficult to restore such land to farmland.

Animal extinction

Many animal species are endangered, and the number of vertebrates at risk alone is staggering. The nature of the threats is varied: Europe's raptors are being threatened by egg collectors, while tigers are in danger of having the dense forests in which they roam cut down. Many endangered animals are beyond saving, while others could survive if protected.

Eight, red tide

Red tide is a body of water in some of the tiny phytoplankton, protozoa or bacteria, in certain environmental conditions, the sudden proliferation and aggregation, caused by a certain range of a period of time in the body of water in the phenomenon of discoloration. Usually the color of the water body is red, yellow, green and brown due to the number and types of red tide organisms.

Red tide, although since ancient times, but with the rapid development of industrial and agricultural production, water pollution is increasing, red tide is also increasingly serious.

The causes of red tide

Red tide is a natural phenomenon that originally existed, or caused by man-made pollution, so far there is no conclusion. However, according to a large number of investigations, the occurrence of red tide must have the following conditions:

① high trophic sea water;

② some special substances involved as triggering factors, known as vitamin B1, B12, iron, manganese, deoxyribonucleic acid;

③ environmental conditions, such as water temperature, salinity, etc., also determines the occurrence of the type of red tide organisms. The type of organisms that occur red tide are mainly algae, 63 kinds of plankton have been found, 24 kinds of diatoms, 32 kinds of methanogens, 3 kinds of cyanobacteria, 1 kind of golden algae, 2 kinds of cryptophytes, 1 kind of protozoa.

Harm of red tide

Red tide not only causes serious harm to the marine environment, marine fisheries and mariculture, but also has an impact on human health and even life. It mainly includes two aspects:

① cause marine anomaly, local interruption of the marine food chain, so that the sea once became the Dead Sea;

② some red tide organisms secrete toxins, these toxins are ingested by certain organisms in the food chain, and if human beings consume these organisms again, it will lead to poisoning or even death.

Nine, soil erosion

Land resources is one of the three major geological resources (mineral resources, water resources, land resources), is the most basic human production activities of resources and labor objects. The degree of human use of land reflects the development of human civilization, but also caused direct damage to land resources, which is mainly manifested in unreasonable cultivation caused by soil erosion, land desertification, land secondary salinization and soil pollution, etc., of which water and soil erosion is particularly serious, and is the world is facing another serious crisis.

Overview of soil and water erosion

Soil and water erosion refers to the whole process of soil erosion, transportation and sedimentation under the action of water flow. In the natural state, the process of surface erosion caused by purely natural factors is very slow and is often in relative equilibrium with the soil formation process. Thus the sloping land remains intact. This type of erosion is called natural erosion, also known as geological erosion. Under the influence of human activities, especially after the serious destruction of human vegetation on the slope, caused by natural factors, surface soil damage and land material movement, the loss process accelerated, that is, soil erosion occurs.

Soil erosion is the most common geological disaster that destroys land resources in China, which is most serious in the Loess Plateau region. China's current general situation of soil erosion is: the point of governance, the surface has expanded, governance can not catch up with the destruction. National soil erosion area of 1.74 billion mu at the beginning of liberation, to 1980 about 600 million mu of governance. Because the treatment could not catch up with the destruction, the soil erosion area expanded to 2.25 billion mu, accounting for about 1/6 of the total area of the country, involving nearly 1,000 counties. The country's mountainous and hilly areas have about 400 million mu of sloping farmland, of which about 100 million mu of terracing, while the other 300 million mu of sloping land is suffering from the dangers of soil erosion.

Soil and water erosion hazards

Decrease in soil fertility, soil erosion can make a lot of fertile topsoil loss.

Reservoir siltation, riverbed elevation, reduced navigability and flooding.

Threatening the safety of industrial and mining transportation facilities. In high mountains and deep valleys, soil erosion often causes mudslide disasters, endangering the safety of industrial and mining transportation facilities.

Deterioration of the ecological environment.

In the 1930s to 1960s, people's understanding of the erosion disaster is still stuck in the land caused by direct economic losses, but in the 1960s, after the beginning of the link to the human environment as a whole by the impact of the environment, including sediment contamination, ecological degradation, etc.

Degradation of the ecological environment.