The second is the rise of the World Ocean level by 2-3 meters due to the melting of polar ice caps.
In the twentieth century, such processes as water, soil, and air pollution, land desertification, deforestation, and so on became widespread. There are such specific phenomena as acid rain. Adverse environmental phenomena have become an essential element of human life, exerting a tangible impact on various aspects of human activity: economics and politics, morale and human health, and much, much more …
In this section, I will try to reveal a number of adverse environmental processes, show the scale of their development and prove that these environmental problems require their solution, they can not wait. After all, today civilization stands as if on a razor’s edge, which every second threatens to fall into the abyss. Mankind balances on the finest line between being and non-being. And this critical limit barely separates our world from the vintage chaos.
The main sources of anthropogenic pollution. The main sources of anthropogenic pollution of the environment are energy producers (TPPs, NPPs, GRES, hundreds of thousands of boiler houses), all industrial facilities (primarily metallurgical, chemical, oil refining, cement and pulp and paper), extensive, re- chemicalized agricultural production, military industry and military facilities, motor transport and other modes of transport (sea, river, railway, air), mining. They pollute the environment with hundreds of toxic substances, harmful physical fields, noise, vibration, and excessive heat.
According to international experts, the primary source and root cause of the rapid development of the global environmental crisis is a population explosion, which is inevitably accompanied by an increase in the rate and volume of natural resources reduction, accumulation of huge amounts of industrial waste, global climate change, and diseases.
With the development of chemistry, metallurgy, energy and mechanical engineering, the world began to be threatened by waste from synthetic detergents, petroleum products, heavy metals, nitrates, radionuclides, pesticides and other harmful substances that are not absorbed by microorganisms, do not decompose , but accumulate in thousands of tons. groundwater.
During the 80 years since the beginning of our century, more minerals have been extracted from the bowels of the Earth than in the entire history of mankind.
Today, as a result of burning fuel resources alone, more than 22 billion tons of carbon dioxide enter the planet’s atmosphere every year. Every year the world industry dumps more than 160 km3 of harmful effluents into rivers, annually 500 million tons of mineral fertilizers and about 4 million tons of pesticides are introduced into the soil by mankind, most of which settles in soils or is carried by surface waters to rivers, lakes, seas and oceans. Over the past 45 years, the use of mineral fertilizers has increased 43 times, and pesticides – ten times.
Another problem, no less important than the previous ones, is the problem of waste. Losses from them are not only huge areas of land occupied by landfills, heaps, slag storages, etc. (for example, a city with a population of 300,000 could be built on the area where landfills are located around Kyiv), but also lethal doses of various toxicants and smoke and dust from them … It would seem that trifles are broken fluorescent lamps in landfills. But each such lamp contains 150 mg of mercury, which can poison about 500 m3 of air.
The main anthropogenic pollutants, in addition to the above, also include various noises from industrial plants, transport, ionizing radiation, vibration, light and thermal effects …
Appendix 3 shows the damage to the body caused by chemical pollutants. Experts believe that about 80-86? air pollutants are concentrated over highly developed industrial areas, 10-15? – over the cities, 1-2? – over the countryside, 0.1? – over the central regions of the oceans. If in a big city 1.5 tons of dust per square kilometer settles per day, then 100 km from it – about 100 times less.
Changes in the atmosphere. In our time, the role of man in the atmosphere has increased. The Earth’s air envelope is one of the most important living conditions. Without food a person can live a month, without water – only a week, but without air a person can not last more than two minutes. The mass of the atmosphere is enormous – 5, 15×1015 tons. However, atmospheric air can be considered an inexhaustible natural resource only conditionally, because a person needs air of a certain quality to live. And under the influence of anthropogenic factors, its chemical composition and physical properties are deteriorating, there are almost how to write an explanatory synthesis no areas left on Earth where the air would retain its original purity and quality.
Greenhouse effect. The climate on our planet has changed periodically in the past. During thousands and millions of years, periods of considerable cooling and even glaciation alternated with warm epochs. Scientists are now very concerned: it seems that the Earth is warming up much faster than it has ever been in the past. This is due to a sharp increase in the content of carbon dioxide in the atmosphere. In the Earth’s atmosphere, carbon dioxide acts like glass in a greenhouse: it transmits sunlight, but retains the heat of the earth’s surface heated by the sun. This causes the planet to warm up, known as the greenhouse effect.
The Earth’s climate depends on many factors – some cause warming, others – cooling (Appendix 5). The curve of natural climate fluctuations now goes downwards, ie to cooling, which exceeds the tendency to increase the temperature due to the greenhouse effect. However, in the near future the result of the interaction of these factors should shift towards increasing temperature.
Recently, scientists’ concern about the greenhouse effect has grown. In addition to CO2, the greenhouse effect is caused by some other gases, which are called small impurities.
What is the danger of the greenhouse effect? According to the calculations of scientists, an increase in the average annual temperature of the Earth by 2.50C will cause significant changes on Earth, most of which will have negative consequences for humans. The greenhouse effect will change critical variables such as precipitation, wind, cloud cover, ocean currents, and the size of polar ice caps. Extthe outer parts of the continents will become drier and the coasts wetter, the winters shorter and warmer, and the summers longer and hotter (Appendix 2).
The most unpleasant for humanity are the two consequences of the greenhouse effect. The first is a significant increase in aridity in the main grain areas (Ukraine, Kuban, etc.). The second is the rise of the World Ocean level by 2-3 meters due to the melting of polar ice caps. This will cause flooding of many coastal areas.
Climate change can also occur due to changes in human type of the Earth’s surface. Replacing forests with cultivated plantations leads to reduced evaporation and increased direct heat transfer. In addition, humanity also directly heats the atmosphere by burning large amounts of oil, coal, peat, and nuclear power plants.
Thus, human activities that cause climate change have different consequences. Some of them raise the temperature, others – lower it and cause the greenhouse effect (deforestation, etc.).
Ozone hole in the atmosphere. It is known that the ozone layer of the atmosphere protects the entire biosphere from the harmful effects of short-wave ultraviolet radiation from the Sun.
Scientists have recently become extremely concerned, as observations by meteorologists working in Antarctica show that the ozone layer over the continent has begun to shrink. There was a pulsating hole in it, the ozone content of which is less than usual by 40-50%. This hole appears in the Antarctic spring (August to October), and from the Antarctic summer it reduces its area. However, there is a tendency to increase its area from year to year. Currently, it is not delayed in summer, and its area exceeds the area of the mainland of Antarctica.
Alarming reports are coming from the Northern Hemisphere: there is also an ozone hole (over the Svalbard archipelago), although smaller than over Antarctica. Decreased ozone content in the atmosphere threatens to reduce crop yields, animal and human diseases, increase harmful mutations, etc.; and if ozone disappears completely, all living things on our planet will be destroyed.
How great is this danger, and what caused the appearance and increase of holes in the ozone layer? According to scientists, a serious threat of ozone depletion will lead to serious consequences. There is no consensus on the cause of ozone holes. It has been found that the destruction of the ozone layer is facilitated by certain chemicals that react with ozone and decompose it into oxygen. As a result, more UV rays reach the Earth. Such substances are widely used in industry (as refrigerants in refrigerators, etc.) and in everyday life (aerosol packaging of cans for paint, varnish, perfume). In 1980, the countries of North America and Western Europe produced as many as 5 billion such canisters. In total, the world annually produces several million tons of CFCs.
Freons are harmless to humans, but they are extremely stable – they can be stored in the atmosphere for up to 80 years. Freon vapors eventually enter the stratosphere with the original air currents. Under the influence of the Sun’s UV radiation, their molecules break down, releasing chlorine atoms. This substance acts as a very strong catalyst, decomposing ozone molecules into oxygen.
Under the threat of the disappearance of the ozone layer, the leaders of many countries have decided to take vigorous measures. In 1985, a convention was signed by the governments of most countries in Vienna, and in the same year in Montreal – a protocol on the protection of atmospheric ozone.
Significant damage to the ozone layer is also caused by flights of high-altitude aircraft, in the exhaust gases of which there are nitrogen oxides; and spacecraft launches, especially such as the American Space Shuttle, which run on solid fuels and emit particularly high levels of such oxides. It is estimated that 300 consecutive Space Shuttle launches could completely destroy the Earth’s ozone layer.
Acid rains. Sulfur and nitrogen oxides, which enter the atmosphere due to the operation of thermal power plants and automobile engines, combined with atmospheric moisture, form small droplets of sulfuric and nitric acids, which are carried by winds in the form of acid fog and fall to the Earth in the form of acid rain.