What is the green revolution in geography. Green revolution
Rapid population growth after the Second World War in countries liberated from colonialism often led to famine in large areas, especially prone to droughts or floods. Such catastrophic events were observed in Ethiopia, Nigeria, India, Pakistan and other countries that did not have strategic food reserves in case of natural disasters. According to calculations international organizations UN, in Africa, Asia and Latin America in the 50-60s. a population explosion was expected, fraught with consequences on a planetary scale. Starvation of people over vast territories would inevitably be accompanied by epidemics of especially dangerous diseases, which would not bypass the development of the country.
Breakthrough in scientific research, associated with the genetics of the main grain crops (wheat, rice, corn), which was carried out in the 50-60s. scientists in India, Korea, Mexico, and the Philippines, along with the widespread use of chemical fertilizers and pesticides, opened new paths in the development of agricultural science and practice. And this has yielded significant results in solving the food problem in a number of developing countries. In Mexican research centers, high-yielding varieties of short-stemmed wheat were developed, suitable for the climatic conditions of the tropical and subtropical zones. High-yielding varieties of rice were developed in the Philippines. These cultures quickly spread to the countries of Asia and Latin America.
This phenomenon was called the Green Revolution in science and agriculture in the 50s and 60s. its first stage came. It was characterized by astonishing progress in increasing the yields of major food crops as a result of the widespread introduction of new semi-dwarf varieties of wheat and rice. The possibilities of combining the extensive development of the agricultural sector of the economy, traditional for developing countries, with intensive methods of agricultural production have expanded. In those regions where, with the help of chemical fertilizers, modern means plant protection, irrigation measures, conditions were created for the use of high-yielding varieties, green revolution became a significant factor in solving the food problem.
Thanks to the green revolution, the predicted large-scale famine was avoided. It also contributed to the growth of farm incomes and accelerated economic development, especially in Asian countries. So, South Korea, already in the 70s. refused to import rice. And although the beneficial consequences of the green revolution for certain countries turned out to be different, in general, throughout the world, since the 60s, grain yields have increased by 65%, and tubers and root crops - by 28%. In Asia, the growth was 85% and 57%, respectively. In Africa, cereal progress has been below world averages due to poorer soil conditions, less intensive monocropping practices, disabilities irrigation, poor development of infrastructures related to agricultural credit, market and supply of industrial goods.
During the green revolution, the problems of transferring new technology, how much improvement of traditional agricultural technology in accordance with the recommendations of modern science, taking into account local conditions. This includes small-scale irrigation, the creation of agrotechnical systems that do not require highly qualified personnel, and the development of farming technology for small peasant farms. International research centers have carried out work to produce grain crops with a high protein content. Special attention paid attention to the implementation of programs related to the production of high-protein crops traditional for underdeveloped countries (millet, sorghum). The Green Revolution allowed us to gain the time necessary to stabilize the “demographic explosion” and alleviate the severity of the food problem.
Despite obvious successes, the first stage of the green revolution stopped a number of unresolved problems. Around the world, the yield of rice grown on irrigated lands is stagnant and even falling. Growing high-yielding varieties of wheat and rice requires a lot of fertilizers and a complex of agricultural machinery. Plant susceptibility to disease remains significant. And this gives rise to many economic problems.
The Green Revolution emphasized the cultivation of wheat and rice at the expense of other products needed for balanced diet. As a result, rural residents faced risks associated with changes in food patterns. Moreover, such the most important areas, such as breeding highly productive breeds in livestock farming and effective fishing methods. At that time, it seemed impossible for developing countries to solve such problems, and for developed countries it looked problematic due to the high energy and material intensity of production, the need for large capital investments, and the scale of the impact on the biosphere.
The experience of the first stage of the green revolution showed that the intensification of agricultural production leads to certain social changes, radical transformations in the economy of a particular country. The strengthening of the market element in the structure of the agricultural sector led to a deterioration in the economic situation of traditional farms that met the food needs of the local population. At the same time, the situation has strengthened modern farms commodity type. They managed, with the support of government organizations, to carry out such agrotechnical measures as the introduction of high-yielding varieties of seeds, pesticides, and irrigation.
Agricultural productivity gains have contributed to polarization social relations in the village. The intensified formation of commodity-type farms involved an increasingly large part of agricultural products into market circulation, capturing not only surpluses, but also the part that is necessary for the reproduction of the labor force. Market needs reduced domestic spending, worsening the already difficult situation of the poorest sections of the peasantry. Low level income of the main part of the population was the most important reason for the aggravation of the regional food situation. Attempts to intensify agricultural production, using Soviet experience or the practice of the developed Western world, did not produce the expected results in solving food problems in developing countries. For example, in the agricultural sector African states neither socialism nor capitalism became the dominant type of economic management. They are characterized by a complex synthesis of capitalist and pre-capitalist relations.
The search for rational forms of land tenure and land use in developing countries has led to the understanding that the efficiency of the agricultural sector is associated not so much with the introduction of new technology, but with an increase in the marketability of traditional agricultural production, focused mainly on self-sufficiency within the framework of historically established community structures. The positive Japanese, South Korean, and Chinese experiences reject the idea of the universal priority of large agricultural enterprises. It is known that Japan, where communal-collectivist traditions are strong and where there is a large shortage of territory suitable for agriculture, has achieved significant results in agricultural development on the basis of relatively small farms, the average size of which is about 1.2 hectares. Small farmers created with government support effective system cooperation that provided access to loans and the latest achievements of modern agricultural technology. Japanese small-scale farming was able to make full use of the arsenal of the green revolution. But the Chinese family economy, based primarily on manual labor and traditional technology and without losing its natural and patriarchal character, it also achieved high gross figures. World experience shows that small (up to two hectares) and medium-sized (five hectares) peasant farms can make a significant contribution to solving regional food problems.
Of primary importance in this process is the allocation of peasants' own plots of land. Then they can provide families with food, and also have a certain surplus for the exchange of goods, which forms the local food market. A significant role here belongs to government regulation, providing preferential financing, sales markets, favorable pricing policy. A national food market is gradually emerging. Relatively small farms are included in cooperative structures with access to the world food market. For example, China has already become an exporter of rice.
As for Western Europe, the USA and Canada, where food problems are solved mainly not through state subsidies to small and medium-sized farms, but through the development of agricultural complexes, the total volume of food production for the population is constantly increasing. Thus, in the countries of the European Economic Community (EEC) in the 60-80s. The annual growth rate in agriculture was about 2%, and in consumption - 0.5%. Therefore, the unified policy of Western European countries in the field Agriculture focused not only on increasing labor productivity, but also certain cases to reduce food surpluses. The latter is done in order to balance supply and demand, reduce the use of chemical fertilizers and plant protection products, and prevent degradative changes in the biosphere.
So, the experience of world agricultural development indicates the presence of two trends.
The first is taking into account the regional specifics of food supply associated with external and internal imbalances in economic development countries, the influence of historical traditions of agricultural production with the specifics of natural and climatic conditions, the ratio of demographic parameters.
The second trend is the formation of a modern national-regional agricultural system in line with global processes. Here is the inclusion of agrarian-industrial complexes of individual countries in the world market, and international division labor, and the global orientation of scientific and technological development, and the effectiveness of economic interaction in food production of regions with various natural and climatic factors, and the need to preserve the natural characteristics of the biosphere.
The harmonious unity of these two trends is necessary condition solutions to the world food problem.
29. "Green Revolution" and its consequences
One of the problems human society on modern stage development is the need to increase food production. This is due to the increase in the planet's population and the depletion of its soil resources.
Temporary positive results in increasing the production of grain crops were achieved in the third quarter of the 20th century. They were achieved in countries where energy consumption increased significantly, progressive forms of agricultural technology were used, and mineral fertilizers were used. Yields of wheat, rice, and corn have increased. New high-yielding plant varieties were developed. The so-called green revolution has occurred. This revolution did not affect countries that did not have sufficient resources.
« Green revolution“occurred both in traditionally used agricultural territories and in newly developed ones. Agrocenoses created by humans for the purpose of obtaining agricultural products have low environmental reliability. Such ecosystems cannot self-heal and self-regulate. As a result of the "green revolution" there was a great impact on the planet's biosphere. The production of energy was inevitably accompanied by air and water pollution. Agrotechnical measures used in soil cultivation have led to soil impoverishment and degradation. Usage mineral fertilizers and pesticides contributed to the atmospheric and riverine anthropogenic influx of nitrogen compounds, heavy metals, organochlorine compounds in the waters of the World Ocean. The widespread use of organic fertilizers has become possible due to an increase in their production volumes.
Facilities for the production and storage of fertilizers and pesticides have made a significant contribution to the accumulation of biosphere pollution.
The Green Revolution arose as a result of the rapid growth of industry and the development of science.
During the Green Revolution, large areas of virgin land were developed. For several years, high yields were collected. But “nothing is given for free” according to one of the provisions of B. Commoner. Today, many of these areas are depleted, endless fields. It will take centuries to restore these ecosystems.
Increased human productivity of ecosystems has led to an increase in the costs of maintaining them in a stable state. But there is a limit to such an increase before it becomes economically unprofitable.
As a result of the “green revolution”, humanity has added global environmental problems.
30. The importance and environmental role of the use of fertilizers and pesticides
Fertilizer property It has been known since ancient times to increase soil fertility and the productivity of cultivated plants grown by humans. Composts, bird droppings, humus, and manure have been used as fertilizers for many thousands of years. Enrichment of the soil with substances necessary for agricultural crops is achieved by plowing green leguminous plants(peas, alfalfa) grown locally. The listed fertilizers are organic.
Soil characteristics can be improved by using mineral (chemical) fertilizers that contain large quantities one or more basic plant nutrients, microelements (manganese, copper, etc.). With the help of mineral fertilizers, you can maintain the balance of nitrogen, phosphorus, and potassium in the soil. If it is necessary to correct the pH value, lime or gypsum is added to the soil. Today, cultures of microorganisms and bacteria that convert organic and minerals into a form that is easily absorbed by plants. Pesticides used by humans to protect plants, agricultural products, wood, wool, cotton, leather, as a barrier to pests and to combat disease vectors. Pesticides are chemical substances, the use of which inevitably has a negative impact on humans and the natural environment. The use of herbicides and pesticides causes the death of a number of soil organisms and changes in the soil-forming process. The use of pesticides must be carried out in accordance with regulations and intended use. Some organochlorine pesticides, particularly DDT, are prohibited for use. The pesticides used are chlordane, hexachlorobenzene, hexachlorocyclohexane and lindane, toxaphene, and mirex. Most of these substances are fat-soluble and accumulate in the fatty tissues of the body of animals and humans, affecting reproductive function, causing cancer, and changes in the nervous system. Pesticides penetrate deeply into the soil - up to 70-115 cm. It should be noted that pesticides migrate in the arable horizon to a depth of up to 200 cm. Pesticides enter the groundwater horizons, which carry contaminants into the surface water at discharge points water bodies. Currently, many agricultural crops that are the basis of the most important food products - grains, oilseeds, vegetables, roots and tubers - are contaminated with organochlorine pesticides.
Non-state educational institution
secondary vocational education
Vologda Cooperative College
Essay
On the theme "Green" revolution
in the discipline "Ecological foundations of environmental management"
Completed by: Pashicheva Yu.V.
Group: 3 GOST
Checked by: Veselova N.V.
Vologda
2010
Table of contents
Introduction……………………………………………………………………….3
Agriculture is a type of human activity………………………4
Pros and cons of biotechnology…………………………………………… ……...5
Consequences of the “green” revolution………………………………………………………….6
Conclusion…………………………………………………………………….7
References……………………………………………………………8
"Green revolution
The “Green” Revolution is a set of changes in the agriculture of developing countries that led to a significant increase in world agricultural production, including the active breeding of more productive plant varieties, the use of fertilizers, and modern technology.
The “green” revolution is one of the forms of manifestation of scientific and technological revolution, i.e. intensive development of agriculture through:
1) technicalization of agriculture (use of machines and equipment);
2) the use of artificially bred varieties of plants and animals;
3) use of fertilizers and pesticides;
4) reclamation (expansion of irrigated lands).
There are two “green revolutions”.
The first “green” revolution occurred in 40-70. XX century, its initiator was the major Mexican breeder Norman Ernest Borlaug. He saved as many people from starvation as no one else had managed before. He is considered the father of the Green Revolution. Despite the known costs inherent in any revolution and the ambiguous perception by the world community of its results, the fact remains: it was it that allowed many developing countries not only to overcome the threat of hunger, but also to fully provide themselves with food.
By 1951-1956 Mexico fully provided itself with grain and began exporting it; over 15 years, grain yields in the country increased 3 times. Borlaug's developments were used in breeding work in Colombia, India, Pakistan, in 1970 Borlaug received the Nobel Peace Prize.
By the mid-1980s, scientists were talking about a second “green” revolution that would occur if agriculture followed the path of reducing anthropogenic energy inputs. It is based on an adaptive approach, i.e. Agriculture needs to reorient itself to more environmentally friendly technologies for cultivating crops and breeding farm animals.
The “green” revolution made it possible not only to feed the growing population of the Earth, but also to improve its quality of life. The number of calories in food consumed per day has increased by 25% in developing countries. Critics of the Green Revolution tried to focus public attention on the excessive abundance of new varieties, the breeding of which allegedly became an end in itself, as if these varieties alone could provide such miraculous results. Of course, modern varieties make it possible to increase the average yield due to more effective ways growing plants and caring for them, due to their greater resistance to insect pests and major diseases. However, they only make it possible to obtain a noticeably larger harvest when they are provided with proper care and the implementation of agrotechnical practices in accordance with the calendar and stage of plant development. All these procedures remain absolutely necessary for transgenic varieties obtained in recent years. However, the application of fertilizers and regular watering, which are so necessary to obtain high yields, simultaneously create favorable conditions for the development of weeds, insect pests and the development of a number of common plant diseases. One of the directions of the second “green” revolution is the use of “environmentally friendly” methods to combat the consequences of anthropogenic interference in ecosystems. For example, after total deforestation, a gross violation of the local biocenosis and ecosystem occurs. In humid areas, moisture stagnates and soils become waterlogged. Such water can become a source of harmful insects - bloodsuckers and disease carriers. Some fish are destroyers of larvae of harmful insects living in water, such as mosquito larvae and midges. Thus, the main trends of the second “green” revolution are to have minimal impact on the natural environment, reduce the investment of anthropogenic energy, and use biological methods to control plant pests.
Almost all of our traditional foods are the result of natural mutations and genetic transformations that serve as the driving forces of evolution. Primitive people who were the first to trace the development cycle of plants can safely be considered the first scientists. As they found answers to the questions of where, when and how certain plants should be grown, in what soils, and how much water each of them requires, they expanded their understanding of nature more and more. Hundreds of generations of farmers have helped accelerate genetic transformation through regular selection using the most fertile and vigorous plants and animals.
Initially, selection was based on artificial selection, when a person selects plants or animals with traits that interest him. Until the XVI-XVII centuries. selection occurred unconsciously, that is, a person, for example, selected the best, largest wheat seeds for sowing, without thinking that he was changing the plants in the direction he needed. Selection as a science took shape only in recent decades. In the past it was more of an art than a science. Skills, knowledge and specific experience, often classified, were the property of individual farms, passing from generation to generation.
Agriculture is a type of human activity.
Agriculture is a unique human activity that can be simultaneously considered as the art, science and craft of managing the growth of plants and animals for human needs. And always main goal This activity continued to increase production, which has now reached 5 billion tons. in year. To feed the growing world population, this figure will have to increase by at least 50% by 2025. But agricultural producers will be able to achieve such a result only if they have access to the most advanced methods for growing the highest-yielding varieties of cultivated plants anywhere in the world.
Agricultural intensification affects the environment and causes certain social problems. However, one can judge the harm or benefit of modern technologies only taking into account the rapid growth of the Earth's population. The population of Asia has more than doubled over 40 years (from 1.6 to 3.5 billion people). What would it be like to have an extra 2 billion people if not for the green revolution? Although the mechanization of agriculture has led to a decrease in the number of farms, the benefits of the “green” revolution, associated with a manifold increase in food production and a steady decline in bread prices in almost all countries of the world, are much more significant for humanity.
And yet, a number of problems (primarily pollution of soils and surface water bodies, largely due to the excessive use of fertilizers and chemical plant protection products) require serious attention from the entire world community. By increasing yields on lands most suitable for crop cultivation, agricultural producers around the world are leaving vast areas of land for other uses virtually untouched. Thus, if we compare world crop production in 1950 and in our time, then with the previous yield, to ensure such growth, it would be necessary to sow not 600 million hectares, as now, but three times more. Meanwhile, there is essentially nowhere to get an additional 1.2 billion hectares, especially in Asian countries, where the population density is extremely high. In addition, the lands involved in agricultural use are becoming more depleted and environmentally vulnerable every year. Yields of major food crops are continuously improving through improved tillage, irrigation, fertilization, weed and pest control, and reduced harvest losses. However, it is already clear that significant efforts will be required, both through traditional breeding and modern agricultural biotechnology, to achieve genetic improvement of food plants at a pace that would meet the needs of 8.3 billion people by 2025.
Pros and cons of biotechnology.
Over the past 35 years, biotechnology using recombinant DNA has emerged as an invaluable new scientific method research and production of agricultural products. This unprecedented penetration into the depths of the genome - to the molecular level - should be considered one of the most important milestones on the path of endless knowledge of nature. Recombinant DNA allows breeders to select and introduce genes into plants “one by one”, which not only sharply reduces research time compared to traditional breeding, eliminating the need to spend it on “unnecessary” genes, but also makes it possible to obtain “useful” genes from a variety of plant species. This genetic transformation promises enormous benefits for agricultural producers, particularly by increasing plant resistance to insect pests, diseases and herbicides. Additional benefits are associated with the development of varieties that are more resistant to a lack or excess of moisture in the soil, as well as to heat or cold - the main characteristics of modern forecasts of future climate disasters.
Today, the prospects for agricultural biotechnology to provide plants that can be used as medicines or vaccines are increasingly realistic. We will simply grow such plants and eat their fruits to cure or prevent many diseases. It's hard to imagine what this might mean for poor countries, where conventional pharmaceuticals are still a novelty and traditional WHO vaccination programs prove too expensive and difficult to implement. This area of research must be fully supported, including through the aforementioned cooperation between the public and private sectors of the economy. Of course, poor countries will have to develop reasonable regulatory mechanisms to most effectively guide the development of production, testing and use of GM products to protect both public health and environment. In addition, the intellectual property of private companies also needs to be protected to ensure fair recovery of past investments and ensure future growth.
The current heated debate about transgenic crops centers on the safety of GMOs. Concerns about the potential dangers of GMOs are based largely on the belief that the introduction of “foreign” DNA into mainstream food crops is “unnatural” and therefore involves an inherent health risk. But since all living organisms, including food plants, animals, microbes, etc., contain DNA, how can recombinant DNA be considered “unnatural”? Even defining the concept of “foreign gene” is problematic, since many genes are common to a wide variety of organisms. The requirements for GM products are much higher than for varieties obtained through conventional breeding and even breeding in which mutations are caused by irradiation or the use of chemicals. At the same time, society must be clearly aware that there is no “zero biological risk” in nature, the idea of which is just the embodiment of the “precautionary principle”, which is not based on any scientific data.
Consequences of the "green" revolution.
The main goal of the “green” revolution was to increase agricultural production. products. But active human intervention in the life of natural ecosystems has led to a number of negative consequences:
1) soil degradation.
Causes:
-technization, chemicalization, land reclamation
2) pollution of the biosphere with pesticides.
Causes:
- chemicalization
3) disruption of the natural balance of ecosystems.
Causes:
-artificial breeding of plant and animal varieties
Soil degradation is a gradual deterioration of soil properties caused by changes in soil formation conditions as a result of natural causes or human economic activity and is accompanied by a decrease in humus content, destruction of soil structure and a decrease in fertility.
The main resource of the agricultural system - soil - is the surface fertile layer of the earth's crust, created under the combined influence of external conditions: heat, water, air, plant and animal organisms, especially microorganisms.
Fertility is the ability of the soil to provide plants with the necessary amount of nutrients, water and air.
Fertility depends on the supply of organic substances - humus, the content of nutrients available to plants, and the provision of moisture. As a result of the use of mineral fertilizers, microorganisms that destroy humus are activated, i.e. Soil fertility is declining.
Pollution of the biosphere with pesticides.
Over the past 50 years, the use of mineral fertilizers has increased 43 times, pesticides 10 times, which has led to the pollution of individual components of the biosphere: soil, water, vegetation. Because of this pollution, the living population of the soil is depleted - the number of soil animals, algae, and microorganisms decreases.
Conclusion.
The Green Revolution has made it possible to achieve success in the war against hunger that humanity is waging. However, scientists emphasize that until the growth rate of the world's population can be slowed down, any achievements of the “green” revolution will be ephemeral. Already today, humanity has technologies (either completely ready for use or in the final stages of development) capable of reliably feeding 30 billion people. Over the past 100 years, scientists have been able to apply their dramatically expanded knowledge of genetics, plant physiology, pathology, entomology and other disciplines to dramatically accelerate the process of combining high plant yields with high tolerance to a wide range of biotic and abiotic stresses.
Literature.
- Arustamov - “Ecological foundations of environmental management.”
M.V. Galperin - “Ecological foundations of environmental management.”
The concept of the Green Revolution became widespread in the 60s of the 20th century. It was at this time that in developing countries, following economically developed countries, transformations in agriculture begin. The Green Revolution is the transformation of agriculture based on modern agricultural technology. It represents one of the forms of manifestation of scientific and technological revolution. The “Green Revolution” includes the following main components: the development of new early-ripening varieties of grain crops, which contribute to a sharp increase in yields and open up the possibility of using further crops; land irrigation, as new varieties can show their best qualities only under the condition of artificial irrigation; widespread use of modern technology and fertilizers. As a result of the Green Revolution, many developing countries began to meet their needs through their own agricultural production. Thanks to the Green Revolution, grain yields have doubled. However, it should be noted that the “green revolution” has become widespread in Mexico, the countries of South and South-East Asia, but had little effect on many other regions. In addition, it affected only lands that belonged to large owners and foreign companies, changing almost nothing in the traditional consumer sector.
TICKET#8
Question 1 Name the main patterns of distribution of fuel resources. Give examples.
The fuel industry is a collection of industries fuel industry, electric power industry, fuel and energy delivery vehicles. Over the past two centuries, the global fuel and energy industry has gone through two main stages in its development. The first stage (XIX - first half of the XX century) was coal, when coal fuel sharply predominated in the structure of the world fuel and energy balance. The second stage was the oil and gas stage. Oil and gas turned out to be more efficient energy carriers than solid fuel. In the 80s The world energy industry has entered the third (transitional) stage of its development, where a transition is taking place from the use of predominantly exhaustible mineral fuel resources to inexhaustible resources. The oil, gas, and coal industries are the basis of global energy. Oil is produced in 80 countries around the world, but the main roles are played by Saudi Arabia, the USA, Russia, Iran, Mexico, China, Venezuela, the UAE, Norway, Canada, Great Britain, and Nigeria. IN international trade 40% of all oil produced comes from A huge territorial gap has formed in the world economy between the areas of its production and consumption, which contributed to the emergence of powerful cargo flows. The main oil production areas are the basins of the Persian Gulf, West Siberian, Caribbean Sea, and Gulf of Mexico. Natural gas is the cheapest and most environmentally friendly fuel. The leader in world gas production is Russia, where the largest basin is located - Western Siberia. The largest gas producing country is the USA, followed by Canada, Turkmenistan, the Netherlands, and the UK. Unlike oil-producing countries, the main gas-producing countries are the developed countries of Europe and North America. By reserves natural gas Two regions are distinguished: the CIS (Western Siberia, Turkmenistan, Uzbekistan) and the Middle East (Iran). The main gas exporters are Russia, which supplies gas to the Eastern and Western Europe; Canada and Mexico, which supply gas to the United States; the Netherlands and Norway, supplying gas to Western Europe; Algeria, which supplies gas to Western Europe and the United States; Indonesia, Middle Eastern countries, Australia exporting gas to Japan. Gas transportation is provided in two ways: by main gas pipelines and with the help of gas tankers when transporting liquefied gas.
The development of the coal industry in the era of cheap oil slowed down, but after the crisis of the 70s. acceleration came again. The main coal-producing countries are developed countries: China, USA, Germany, Russia, Poland, Australia, India, South Africa. In Russia in last years Coal production is falling sharply, while in China and the USA the coal industry is developing dynamically. In terms of explored coal reserves, the leaders are also mainly developed countries: the USA, the CIS (Russia, Ukraine, Kazakhstan), then China, Germany, Great Britain, Australia, South Africa. Most coal is consumed in the same countries where it is mined, so only 8% reaches the world market. But there have been changes in the structure of trade - the demand for coking coal is falling due to the slowdown in the development of metallurgy, and the demand for thermal coal is growing. The main exporters of coal are the USA, Australia, and to a lesser extent South Africa, Russia, Poland, and Canada. The main importers of coal are Japan, the Republic of Korea and a number of European countries.
One of the main problems generated by the demographic situation in the world is providing food for a rapidly growing population. Every year, 90–100 million new eaters appear in the world, and the global community, with all its technological power, cannot yet adequately feed even those hungry people who already exist. Not a single country in the world has yet managed to improve welfare and achieve economic development without first sharply increasing food production, the main source of which has always been agriculture.
The food problem is multifaceted; it has social, economic and environmental aspects. Until the twentieth century, most people on the planet did not have enough food to live a normal or even tolerable life. From famine, an extreme manifestation of the food problem, in the 20s. XX century 2/3 of humanity suffered. At the end of the century, this share dropped to 1/4 of the planet's population, but taking into account the demographic explosion, the absolute number of hungry people did not decrease. According to the FAO (Food and Agriculture Organization of the United Nations), currently more than 1 billion people in the world are undernourished and hungry, about 10 million people die from hunger every year and 100 million are at risk of death. The number of people whose food calorie content is less than the critical norm (1400–1600 kcal/day) is about 700 million people. (For comparison, the calorie content of the food of Auschwitz prisoners was approximately 1,700 kcal.)
Let us note, however, that for economically developed countries, where less than 15% of the world's population lives, the phenomenon of hunger or malnutrition is not typical. In the USA and France, the level of food self-sufficiency exceeds 100%, in Germany it is 93%, in Italy – 78%. These countries now produce and consume more than 3/4 of the world's food. Overeating and excess weight become typical for their residents. The total number of such overeaters is estimated at 600 million people - about 10% of the world's population. In the United States, more than half of people aged 20 and older fall into this category.
The main source of food for humans is agriculture. At the same time, the main resource for agriculture is fertile, plowed soils. But the area of arable land is constantly decreasing. This process is especially intense at the present time - huge areas of arable land are being taken away for the construction of cities, industrial enterprises, roads, and are being “eaten up” by ravines.
Desertification processes cause great damage to agricultural lands: deflation and erosion occur at an accelerated pace, and vegetation cover is destroyed. As a result of unsystematic use over the entire history of civilization, about 2 billion hectares of productive lands turned into deserts: at the dawn of agriculture, productive lands amounted to about 4.5 billion hectares, and now there are about 2.5 billion hectares left.
The area of anthropogenic deserts is approximately 10 million km 2, or 6.7% of the total land surface. The desertification process is progressing at a rate of 6.9 million hectares per year and is already extending beyond the landscapes of the arid zone. About 30 million km2 (about 19%) of land are under threat of desertification.
The Sahara, the greatest desert in the world (9.1 million km 2), is threateningly expanding its borders. According to official data from the authorities of Senegal, Mali, Niger, Chad and Sudan, the rate of annual advance of the edge of the Sahara ranges from 1.5 to 10 m. Over the past 50 years, its area has increased by 700 thousand km 2. But relatively recently, in the 3rd millennium BC, the territory of the Sahara was a savannah with a dense hydrographic network. Nowadays the sand cover there reaches half a meter in height.
Along with the absolute reduction in the area of agricultural land, there is a relative decrease due to the rapid growth of the planet's population. Currently, there is about 0.3 hectares of arable land per inhabitant of the planet. (For comparison and to fuel patriotic feelings, we note that in Russia this value is about 0.9 hectares!)
It is believed that if 1 ton of grain is collected per person per year from 1 hectare, then there will be no problem of hunger. The planet's six billion population requires 6 billion tons of grain, but only about 2 billion are harvested. One of the reasons for this is the small area of arable land per person and their overall low productivity. The earth today is not able to feed all its inhabitants.
There is another calculation. In the biosphere, humanity occupies the top of the ecological pyramid and therefore must form a biomass that is significantly less than the biomass of living matter in the biosphere as a whole. According to a number of ecologists, the biosphere remains stable if there is at least 250 tons of living matter per capita per year. Taking into account the total bioproduction of the biosphere, the permissible population of our planet is 3–4 billion people.
Therefore, it is no coincidence that global ecological problems(including food) began to appear precisely after total number people on Earth have exceeded this limit. Now, every year, in the context of exponential population growth, the severity of these problems is increasing.
Until the middle of the 20th century. few people thought about the fact that production cannot increase indefinitely and will certainly run into limited natural resources, including soil, necessary for agriculture.
Analysis of the situation shows that extensive path solving the food problem by expanding the area for agricultural products and developing existing reserve lands is unpromising. The rate of such growth lags and will continue to lag behind the rate of population growth. It is predicted that the global per capita arable land supply will decrease threefold by the middle of this century.
These circumstances are directly related to the attempt to solve the food problem intensively, called "green revolution" . This was the name given to the breakthrough achieved in food production on the planet in the 1960s. The “father” of the “green revolution” is considered to be the American plant breeder prof. Norman E. Borlaug, Nobel Peace Prize laureate 1970. Due to mechanization, chemicalization, irrigation, increasing the power supply of farms, the use of new higher-yielding and more disease-resistant varieties of crops, the most productive breeds of livestock, it was possible to increase agricultural production from the same and even smaller areas.
The Green Revolution temporarily eliminated the problem of hunger in tropical areas of the world. Thanks to the widespread distribution of high-yielding and low-growing varieties of wheat and rice in the tropical regions of Asia and Africa, which suffered most from food shortages, many developing countries were able to overcome the threat of famine for a certain period of time.
At the World Food Conference in Rome in 1974, the decision was made to end hunger within a decade. The main hopes then were placed on the intensification of agriculture through the development of new highly productive varieties of plants and animal breeds, the chemicalization of agriculture, the use of powerful equipment and new technologies. However, it was 10 years after the conference and 14 years after Borlaug received the Nobel Prize, in 1984, that the food crisis sharply worsened, caused primarily by a severe drought in the Sahel region of Africa, which claimed millions of lives.
Despite the achievements of the “green revolution”, a rather difficult food situation still persists. There are more malnourished and hungry people around the globe than ever before, and their numbers are growing. The famine zone covers a vast area on both sides of the equator, including Asia, primarily its southeastern part, the Caribbean countries and South America, almost all of sub-Saharan Africa. In the latter region there are countries (Chad, Somalia, Uganda, Mozambique, etc.) where the proportion of hungry and malnourished people is 30–40% of the population.
Scientists and practitioners, politicians and economists involved in solving the food problem believe that the “green revolution” has floundered, and see several reasons for this.
Today's new varieties of cultivated plants alone cannot provide miraculous results. They need proper care, strict implementation of agrotechnical practices in accordance with the calendar and stage of plant development (rationing of fertilizers, watering with humidity control, weed and insect pest control, etc.).
New grain varieties are very sensitive to fertilizers, in addition, they need more water than older ones to realize their potential; they are more susceptible to disease. This means that the farmer must have special knowledge for growing new varieties, as well as funds for the purchase of fertilizers, irrigation mechanisms, and pesticides. When all this was carried out under the guidance of specialists and within the framework of the International Agricultural Program, the positive result was obvious. However, in remote areas of Asia, Africa and South America, the technologies of the “green revolution” were inaccessible to most peasants. The rural population of third world countries turned out to be unprepared for the technological revolution that characterizes agriculture in economically developed countries.
When assessing the possibilities of an intensive development path, one should also keep in mind that the potential of mechanization, irrigation, and chemicalization is currently largely exhausted. For example, there has been a sharp reduction in irrigated areas due to limited water resources.
The German philosopher F. Engels in “Dialectics of Nature” warned “... not to be too deluded by our victories over nature. For every one of these, she takes revenge on us. Each of these victories, however, has, first of all, the consequences that we were counting on, but in the second and third place completely different, unforeseen consequences, which very often destroy the consequences of the first ones.”
The Green Revolution also had unforeseen consequences. Primarily soil salinization, caused by poorly designed and maintained irrigation systems, and soil and surface water pollution, largely due to improper use of fertilizers and crop protection chemicals.
When using chemicals for their intended purpose, it is usually impossible to prevent their release into the air, soil or water. These substances can harm humans, animals, plants, microorganisms, as well as buildings and structures, machines and mechanisms.
The harm caused to living environmental objects is due, in particular, to the fact that these chemicals are toxic (poisonous), carcinogenic (capable of causing cancer), mutagenic (capable of affecting heredity), teratogenic (capable of causing deformities), etc. The consequences of simultaneous exposure to several substances on the environment are still poorly understood.
Some harmful chemical compounds, once in the natural cycle, turn into harmless ones, while others retain their properties for years and decades. These latter, even with a small degree of their concentration in the environment, having entered a living organism (human, animal or plant), are almost not removed from it or are removed very slowly. These substances accumulate and their concentration becomes dangerous.
New grain varieties are very sensitive to fertilizers. In fact, high yields can only be achieved by applying large amounts of fertilizer. Particularly widespread are inexpensive nitrogen fertilizers based on synthetic ammonia, which have become an integral attribute of modern crop production technologies. Today, the world consumes over 80 million tons of nitrogen fertilizers annually. According to experts who study nitrogen cycles in nature, at least 40% of the 6 billion people currently inhabiting the planet are alive only thanks to the discovery of ammonia synthesis. It would be completely impossible to introduce this amount of nitrogen into the soil using organic fertilizers.
High doses of mineral fertilizers often worsen the quality of agricultural products, especially in arid areas where the mechanisms of microbiological denitrification are suppressed. Consumption of such products by animals and humans leads to indigestion and acute poisoning.
Mineral fertilizers have a direct and indirect effect on the properties of soils and on the development of biological processes in natural waters. Studies have shown that long-term application of such fertilizers without liming causes an increase in soil acidity and accumulation of toxic compounds of aluminum and manganese, which reduces fertility and leads to soil degradation.
Fertilizers are washed off from the fields due to their irrational use or, not absorbed by plants, are washed out of the soil by heavy rains and end up in the soil. groundwater and into surface water bodies.
The ions of nitrates, phosphates, and ammonium present in fertilizers, entering water bodies with wastewater, contribute to their overgrowing with phytoplankton.
For the normal functioning of aquatic ecosystems they must be oligotrophic, i.e. poor nutrients. In this case, there is a dynamic balance of all groups of organisms in the ecosystem - producers, consumers and decomposers. When nitrates and especially phosphates enter water bodies, the rate of production—photosynthesis of organic matter by phytoplankton—begins to exceed the rate of consumption of phytoplankton by zooplankton and other organisms. The reservoir “blooms” - blue-green algae begin to predominate in the phytoplankton, some of them give the water an unpleasant odor and taste, and can release toxic substances. Favorable conditions for the life of anaerobic organisms are formed. When algae decomposes as a result of a number of interconnected fermentation processes in water, the concentration of free carbon dioxide, ammonia, and hydrogen sulfide increases. The phenomenon of saturation of water with nutrients, which promotes increased growth of algae and bacteria that consume decaying algae and absorb oxygen, and leading to the death of higher aquatic biota, is called eutrophication.
Dependence of phytoplankton growth on phosphate content in water
Soluble nitrogen compounds not only contribute to the growth of water bodies (like phosphates), but also increase the toxicity of water, making it hazardous to human health if such water is used as drinking water. Getting into the saliva and small intestine with food, nitrates are microbiologically reduced to nitrites, resulting in the formation of nitrosyl ions in the blood, which can oxidize iron Fe(II) in blood hemoglobin to iron Fe(III), which prevents the binding of oxygen by hemoglobin. As a result, symptoms of oxygen deficiency occur, leading to cyanosis. When 60–80% of the iron (II) hemoglobin converts to iron (III), death occurs.
In addition, nitrites form nitrous acid and nitrosamines (together with organic amines from animal and plant foods) in the acidic environment of the stomach, which have a mutagenic effect. We also note that the water of eutrophicated reservoirs is aggressive towards concrete, destroys materials used in hydraulic construction, and clogs filters and pipelines of water intake devices.
Part of the Green Revolution program to increase crop yields was the widespread use of pesticides.
Pesticides have been used before, these were the so-called. first generation pesticides are toxic inorganic substances that included arsenic, cyanide, and some heavy metals, such as mercury or copper. They had low efficiency and did not save from catastrophic crop losses, such as potato late blight in almost all of Europe. mid-19th c., which became the cause of mass famine. In addition, these pesticides altered the mineral and biotic composition of the soil so much that in some places it still remains infertile.
They were replaced by second generation pesticides based on synthetic organic compounds. DDT (dichlorodiphenyltrichloromethylmethane) played a special role among them. Studying the properties of this substance back in the 1930s. was studied by the Swiss chemist Paul Müller.
DDT turned out to be extremely toxic to many insect pests, relatively harmless, it seemed, to humans and other mammals, persistent (difficult to break down and provide long-lasting protection against insect pests), and relatively cheap to produce. DDT was also effective in combating insects that carry the infection. Thanks to the widespread use of DDT, organized by the UN World Health Organization (WHO), mortality from malaria has significantly decreased and millions of lives have been saved.
The merits of DDT seemed so undeniable that Muller received the Nobel Prize for his discovery in 1948. However, over the next two decades, serious negative consequences of DDT were discovered. Accumulating in trophic chains, chlorinated hydrocarbons (DDT and a family of similar pesticides) became dangerous toxicants, reducing resistance to disease, negatively affecting reproductive abilities and thermoregulation. Numerous cases of death of various aquatic biota (river and sea), birds and other animals were noted. For example, DDT carried by rivers into the ocean killed predators that fed on the eggs of crown-of-thorns starfish. As a result, these previously quite rare marine inhabitants multiplied in such numbers that they began to threaten the ecological balance, destroying hundreds of square kilometers of coral reefs. In the early 1970s. the use of DDT was banned in most developed countries (including the USSR, where it was widely used in cotton fields).
In addition, pesticides have a detrimental effect on the health of primarily the rural population, people engaged in agricultural work. WHO estimates that they still kill 20,000 people every year and sicken millions of people, mostly in developing countries.
Currently, increasing attention is being paid to ecological methods of controlling agricultural pests, based on finding natural enemies and “pitting” them on the pest without affecting other species. According to entomologists, only a hundredth of the thousands of known species of herbivorous insects are serious pests; the populations of the rest are kept at such a low level by one or more natural enemies that they cannot cause significant damage. Thus, the first place is not pest control, but the protection of their natural enemies.
However, one should also remember the unpredictability of artificial intervention in stable biocenoses. Here is a textbook example: immediately after the Second World War, on the recommendation of the WHO, to combat malaria on the island of Kalimantan (Indonesia), the area was sprayed with DDT. The mosquitoes killed by the insecticide were eaten by cockroaches. They themselves did not die, but became slow and were eaten in large numbers by lizards. In the lizards themselves, DDT caused nervous disorders, weakened reactions, and they became victims of cats.
The extermination of lizards by cats led to the proliferation of caterpillars, which began to eat the thatched roofs of the aborigines. The death of cats, which eventually also became poisoned by DDT, led to the fact that the villages were overrun by rats living in symbiosis with fleas carrying plague bacilli. Instead of malaria, the inhabitants of the island received another, more terrible disease - the plague.
WHO stopped its experiment and brought cats to the island, which restored the ecological balance in its ecosystems. Cat raids to combat rats landed on small islands in Japan in 1961 and on islands in Malaysia in 1984 and 1989.
The failures of third world countries and international organizations promoting their development, trying to achieve an adequate return on investment in agriculture as part of the implementation of the “green revolution”, indicate, according to many experts, the need second "green revolution" . Now the emphasis is on new biotechnologies, including genetic engineering.
Over the past 30 years, biotechnology has emerged as a scientific method for the research and production of agricultural products. However, the attitude towards genetic engineering is still controversial both among producers and consumers of agricultural products.
Proponents of genetic modification of plants argue that selection at the molecular level makes it possible to create varieties that are resistant to insect pests, diseases and herbicides, lack or excess of moisture in the soil, and heat or cold. It also makes it possible to widely use local plant varieties that are best adapted to certain climatic conditions of the region, which contributes to the conservation of biological diversity as the most important factor sustainable development. It is claimed that new varieties can be given high nutritional characteristics and other properties that have a beneficial effect on health. Opponents of the creation of genetically modified plants and genetically modified food products, belonging mainly to “green” organizations, consider this last statement to be the most controversial and dangerous, a threat to humans and nature, since the consequences of such modifications are unpredictable. At the large-scale World Manufacturers Forum in Turin (Italy), 5 thousand participants from 180 countries came to a clear conclusion: GMOs (genetically modified organisms) are no good, they are harmful to the environment, to the health of people and animals. In the USA, where a decade and a half ago the world's first genetically modified product(tomatoes), now 20% of the cultivated area is allocated for the production of environmentally friendly products.
According to A. Baranov, President of the National Association of Genetic Safety, the rejection of transgenic products occurring all over the world is a “revolution from below”; consumers vote with their wallets against them, for environmentally friendly products not only without pesticides, but also without GMOs. But nevertheless, for 10 years now in all boiled sausages, which we buy and eat in Russia, the filler that determines both the color and taste is GM corn and GM soybeans.
Disputes about genetically modified organisms continue; they have not only an applied – scientific and economic, but also a philosophical and even political nature.
Pesticides are substances used to control agricultural pests and weeds. They are divided into groups depending on the organisms they are intended to combat. For example, herbicides destroy plants, insecticides destroy insects.