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What is the greenhouse effect definition. Theoretical Scenarios of Global Climate Perturbations

Greenhouse effect- the rise in temperature on the surface of the planet as a result of thermal energy that appears in the atmosphere due to the heating of gases. The main gases that lead to the greenhouse effect on Earth are water vapor and carbon dioxide.

The phenomenon of the greenhouse effect makes it possible to maintain a temperature on the Earth's surface at which the emergence and development of life is possible. If there were no greenhouse effect, average temperature the surface of the globe would be much lower than it is now. However, as the concentration of greenhouse gases rises, the atmosphere's impermeability to infrared rays increases, which leads to an increase in the temperature of the Earth.

In 2007, the Intergovernmental Panel on Climate Change (IPCC) - the most authoritative international body that brings together thousands of scientists from 130 countries - presented its Fourth Assessment Report, which contained generalized conclusions about past and current climate change, their impact on nature and humans , as well as possible measures to counteract such changes.

According to published data, from 1906 to 2005, the average temperature of the Earth rose by 0.74 degrees. In the next 20 years, temperature growth, according to experts, will average 0.2 degrees per decade, and end of XXI century, the temperature of the Earth can rise from 1.8 to 4.6 degrees (such a difference in the data is the result of superimposing a whole range of future climate models that take into account various scenarios for the development of the world economy and society).

According to scientists, with a 90 percent probability, observed climate changes are associated with human activities - the burning of carbon fossil fuels (i.e. oil, gas, coal, etc.), industrial processes, as well as the deforestation - natural sinks of carbon dioxide from the atmosphere .

Possible impacts of climate change:
1. Change in the frequency and intensity of precipitation.
In general, the climate on the planet will become more humid. But the amount of precipitation will not spread evenly across the Earth. In regions that already receive enough rainfall today, their fallout will become more intense. And in regions with insufficient moisture, dry periods will become more frequent.

2. Sea level rise.
During the 20th century, the average sea level rose by 0.1-0.2 m. According to scientists, in the 21st century, the sea level rise will be up to 1 m. In this case, coastal areas and small islands will be the most vulnerable. States such as the Netherlands, Great Britain, as well as the small island states of Oceania and the Caribbean will be the first to fall under the risk of flooding. In addition, high tides will become more frequent, and coastal erosion will increase.

3. Threat to ecosystems and biodiversity.
There are forecasts for the extinction of up to 30-40% of plant and animal species, as their habitat will change faster than they can adapt to these changes.

With an increase in temperature by 1 degree, a change in the species composition of the forest is predicted. Forests are a natural carbon store (80% of all carbon in terrestrial vegetation and about 40% of carbon in soil). The transition from one type of forest to another will be accompanied by the release of a large amount of carbon.

4. Melting glaciers.
The current glaciation of the Earth can be considered one of the most sensitive indicators of ongoing global changes. Satellite data show that since the 1960s there has been a decrease in the area of snow cover by about 10%. Since the 1950s in the Northern Hemisphere, the area sea ice decreased by almost 10-15%, and the thickness decreased by 40%. According to forecasts by experts from the Arctic and Antarctic Research Institute (St. Petersburg), in 30 years the Arctic Ocean will completely open from under the ice during the warm period of the year.

According to scientists, the thickness of the Himalayan ice is melting at a rate of 10-15 m per year. At the current rate of these processes, two-thirds of the glaciers will disappear by 2060, and by 2100 all glaciers will have completely melted.
Accelerated glacier melt poses a range of immediate threats human development. For densely populated mountainous and foothill areas, avalanches, floods or, conversely, a decrease in the full flow of rivers, and as a result, a reduction in reserves, are of particular danger. fresh water.

5. Agriculture.
Impact of warming on productivity Agriculture ambiguously. In some temperate areas, yields may increase with a small increase in temperature, but decrease with large changes in temperature. In tropical and subtropical regions, overall yields are projected to decline.

The most serious blow can be dealt the poorest countries least prepared to adapt to climate change. According to the IPCC, by 2080 the number of people facing the threat of hunger could increase by 600 million, twice the number of people living in poverty today in sub-Saharan Africa.

6. Water consumption and water supply.
One of the consequences of climate change could be a lack of drinking water. In dry regions ( central Asia, mediterranean, South Africa, Australia, etc.) the situation will be further aggravated due to the reduction in precipitation.
Due to the melting of glaciers, the flow of the largest waterways in Asia - the Brahmaputra, the Ganges, the Yellow River, the Indus, the Mekong, Salween and the Yangtze - will significantly decrease. The lack of fresh water will affect not only human health and agricultural development, but will also increase the risk of political divisions and conflicts over access to water resources.

7. Human health.
Climate change, according to scientists, will lead to increased health risks for people, especially for the poorer segments of the population. Thus, a reduction in food production will inevitably lead to malnutrition and hunger. Abnormally high temperatures can exacerbate cardiovascular, respiratory and other diseases.

An increase in temperature may change geographical distribution various kinds that are carriers of diseases. As temperatures rise, the ranges of heat-loving animals and insects (such as encephalitic mites and malaria mosquitoes) will spread further north, while the people inhabiting these areas will not be immune to new diseases.

According to environmentalists, humanity is unlikely to be able to prevent completely predictable climate change. However, it is humanly possible to mitigate climate change, to restrain the rate of temperature increase in order to avoid dangerous and irreversible consequences in the future. First of all, due to:
1. Restrictions and reductions in the consumption of fossil carbon fuels (coal, oil, gas);
2. Improving the efficiency of energy consumption;
3. Implementation of energy saving measures;
4. Greater use of non-carbon and renewable energy sources;
5. Development of new environmentally friendly and low-carbon technologies;
6. Through prevention forest fires and reforestation, as forests are natural sinks of carbon dioxide from the atmosphere.

The greenhouse effect takes place not only on Earth. A strong greenhouse effect is on the neighboring planet, Venus. The atmosphere of Venus is almost entirely composed of carbon dioxide, and as a result, the surface of the planet is heated to 475 degrees. Climatologists believe that the Earth avoided such a fate due to the presence of oceans on it. The oceans absorb atmospheric carbon and it accumulates in rocks such as limestone - through this carbon dioxide is removed from the atmosphere. There are no oceans on Venus, and all the carbon dioxide emitted into the atmosphere by volcanoes remains there. As a result, an uncontrollable greenhouse effect is observed on the planet.

The material was prepared on the basis of information from RIA Novosti and open sources

The main contribution to the "greenhouse" effect of the earth's atmosphere is made by water vapor or air humidity in the troposphere (Table 3).

At the same time, the concentration of water vapor in the troposphere significantly depends on the surface temperature: an increase in the total concentration of "greenhouse gases" in the atmosphere should lead to an increase in humidity and the "greenhouse" effect, which in turn will lead to an increase in surface temperature.

With a decrease in surface temperature, the concentration of water vapor decreases, which leads to a decrease in the "greenhouse" effect, and at the same time, with a decrease in temperature in the polar regions, a snow-ice cover is formed, leading to an increase in albedo and, together with a decrease in the "greenhouse" effect, causing a decrease in the average surface temperature.

Thus, the climate on the Earth can pass into the stages of warming and cooling, depending on the change in the albedo of the Earth-atmosphere system and the "greenhouse" effect.

Anthropogenic pollution of the Earth's atmosphere is one of the causes of the "greenhouse" effect, which is understood as a possible increase in the global temperature of the globe as a result of changes in the heat balance caused by the so-called "greenhouse gases".

The earth's surface receives mainly a stream of visible rays that pass through the "greenhouse gases" without changing. In near-Earth space when meeting with various bodies a significant part of these rays is transformed into long-wave (infrared) thermal rays. "Greenhouse gases" prevent the escape of heat rays into outer space and thereby cause an increase in air temperature (the "greenhouse" effect).

The main "greenhouse gas" is carbon dioxide (CO 2). Its contribution to the "greenhouse" effect, according to various sources, ranges from 50 to 65%. Other "greenhouse gases" include methane (about 20%), nitrogen oxides (about 5%), ozone, freons (chlorofluorocarbons) and other gases (about 10-25% of the "greenhouse" effect). In total, about 30 "greenhouse gases" are known. Their warming effect depends not only on the amount in the atmosphere, but also on the relative activity of the action per molecule. If, according to this indicator, CO 2 is taken as a unit, then for methane it will be equal to 25, for nitrogen oxides - 165, and for freon - 11000.

The main anthropogenic source of CO 2 entering the atmosphere is the combustion of carbonaceous fuel (coal, oil, fuel oil, methane, etc.). Now, only about 1 ton of carbon per person per year enters the atmosphere from thermal power engineering alone; According to forecasts, in the first half of the 21st century, the release will reach more than 10 billion tons.

Over the past 200 years, the concentration of CO 2 in the air has increased from 275 to 350 particles per 1 million air particles, that is, by 25%, and since 1958. by 2001, the concentration of CO 2 increased from 350 to 368 particles (Table 4). If mankind does not take measures to reduce the emission of gases, then by the middle of the century the average global temperature of the surface atmosphere will increase by 1.5-4.5 0 C. The shares of some states in the emission of carbon dioxide are as follows: the USA - 22%, Russia and China - 11% each, Germany and Japan - 5% each.

At present, the danger lies in the fact that the concentration of "greenhouse gases" in the atmosphere, namely carbon dioxide, nitrogen, water vapor and many others, has increased significantly and is associated with the industrial development of mankind. Over the past 150 years, nitrogen content has increased by 18%, methane by almost 150%, and carbon dioxide by more than 30%. As a result, there was a certain stimulation of the "greenhouse" effect with the corresponding consequences.

According to scientists, 330 billion tons of this substance annually take part in the carbon cycle on the planet. The share of man in this volume is very small - 7.5 billion tons, but this is enough to upset the balance of the system.

Recognizing the problem global warming climate change, the World Meteorological Organization (WMO) and the United Nations Program for environment(UNEP) established in 1988 the Intergovernmental Panel on Climate Change (IPCC). This is actually a permanent forum of several thousand scientists different countries, including dozens of Russian ones, practically everyone who deals with this problem from different angles: climatologists, ecologists, economists and power engineers. Approximately once every 4-5 years, scientists publish their multi-page reports on the state of the Earth's climate. The "first report" of experts in 1990 contained rather modest statements about ongoing climate fluctuations, scientists were sure of one thing for sure - there was an increase in the concentration of carbon dioxide in the atmosphere. The average level of carbon dioxide in the atmosphere according to the WMO over the past 30 years has increased from 340 to 390 parts per million. Researchers' confidence has increased every year. Back in 2006, 70% of experts were sure that humans are to blame for global climate change, but already from the fourth IPCC report in 2007 it became clear that the number of experts who are confident in this has increased to 90-95%.

The problem of reducing emissions of "greenhouse gases" is engaged in almost the entire world community, both at the political and industrial and environmental levels. An example of a competent policy to reduce emissions of "greenhouse gases" is the Kyoto Protocol of 1997. In December 1997, an international conference on global climate change on the planet was held in Kyoto, which was attended by representatives from 159 countries. The final protocol was adopted, which provided for a total reduction of 5.2% in emissions of "greenhouse gases" into the atmosphere. By 2008-2012 the countries of the European Union should reduce emissions of "greenhouse gases" (from the level of 1990) by 8%, the USA - by 7%, Japan, Canada - by 6%. Russia and Ukraine by 2012 can keep emissions at the level of 1990 due to a decrease industrial production V last years. An example of the industrial reduction of CO 2 emissions is the work carried out in Japan in 2007-2008. to reduce carbon dioxide emissions as a result of the dissolution of flue gases after gas-using installations in sea water. However, this technical solution did not give the expected results, and work in this direction was stopped.

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If we consider actual problems humanity, we can conclude that the most global of them is the greenhouse effect. It is already making itself felt and greatly changing environmental conditions, but its exact consequences are unknown, although it is clear that they may be irreparable.

To save humanity, you should find out the essence of the greenhouse effect and try to stop it.

What it is

The essence of the greenhouse effect is similar to the principle of operation of greenhouses, which is well known to all gardeners and gardeners. It lies in the fact that a certain greenhouse is formed above the planet, which, having transparency, freely passes the sun's rays through itself. They fall on the earth's surface, warm it up. Heat should normally pass through the atmosphere, and its lower layers over the past few decades have become so dense that they have lost their throughput. Thus, heat transfer is disturbed, which leads to the launch of the greenhouse effect mechanism.

The definition of the greenhouse effect is approximately as follows: an increase in temperature in the lower atmospheric layers compared to effective indicators characterizing the thermal radiation of the Earth, which is observed from space. In other words, it is much warmer on the surface of the planet than outside of its atmosphere. And since the layers are very dense, they do not allow heat to pass through, and it, under the influence of low cosmic temperatures, provokes the formation of condensate. A simplified diagram of the mechanism is shown below.

For the first time, Joseph Fourier took up the study of the greenhouse effect in the 19th century, who suggested that earth atmosphere changes greatly and in its properties begins to resemble glass in greenhouses, that is, it transmits the sun's rays, but prevents the reverse penetration of heat. Because of this, the so-called are synthesized, which consist of carbon, water vapor, ozone and methane.

The basis is steam, which provokes the formation of condensate. An equally important role in the greenhouse effect is played by carbon dioxide, the volume of which is Lately increased to 20-26%. The shares of ozone and methane in the atmosphere are 3-7% each, but they also take part in the processes of the greenhouse effect.

Causes

Planet Earth has already gone through the greenhouse effect and global warming, and, probably, without such phenomena, humanity and all living things would not be able to develop and live normally. Many centuries ago, the processes started due to the high activity of numerous volcanoes, the eruption products of which fell into the atmosphere. But as vegetation spread on the planet, the level of gases decreased, and the situation stabilized.

IN modern world The greenhouse effect is due to the following reasons:

Active and uncontrolled use of various minerals extracted from the bowels of the Earth, which have combustible properties. Mankind strives to use all the gifts of the planet, but does it extremely thoughtlessly and rudely: in the process of burning and burning, a huge amount of various decay products polluting the atmosphere, as well as carbon dioxide, are released into the environment every day.
Active deforestation throughout the Earth, which has recently become simply huge. Trees are felled mainly for fuel use, but land is sometimes cleared for construction. One way or another, a decrease in the number of green plants changes the composition of the air. Leaves absorb carbon dioxide and release oxygen. And the less vegetation on the planet, the higher the concentration of substances that thicken the atmosphere and enhance the greenhouse effect.
A huge number of vehicles running on gasoline. During its operation, they are produced and immediately enter the air. They rush up, penetrate into the lower atmospheric layers and make them even denser, enhancing the greenhouse effect.
The development of the greenhouse effect in the atmosphere contributes to the rapid growth of the population. Each person, inhaling oxygen, exhales carbon dioxide, and, as you know, it is the main development of the greenhouse effect.
Forest fires, which are increasingly occurring due to weather changes and human negligence, are also exacerbating the greenhouse effect. A huge number of trees are burned every year, which means that incredible amounts of carbon dioxide are released into the air and atmosphere.
Numerous landfills that have flooded the surface of the Earth, in the process of decay of waste, emit methane and other harmful substances that greatly pollute the lower atmospheric layers.
The rapid pace of industrial development. Various processing plants and other industrial companies emit a huge amount of exhaust and vapors that enter the atmosphere almost immediately and provoke a greenhouse effect.
The introduction of chemical and synthetic substances into all spheres of life. They are found in fertilizers, containers, clothing, food and other products of modern production. Some compounds do not decompose and emit vapors that rush into the atmosphere.

Possible consequences

It is not enough to know what the greenhouse effect is in order to understand how dangerous it is. And in order to assess the globality and seriousness of the problem, one should consider the consequences that threaten the planet and all living things. They may be as follows:

Air pollution and thickening of its layers contribute to global warming. For a long time, scientists engaged in research climatic conditions, noticed an increase in average annual temperatures by several degrees. And such changes can upset the overall balance, lead to heat and drought in some southern regions.
Due to the greenhouse effect and the warming caused by it, active is taking place. The water level in the oceans is growing rapidly, coastal areas may be completely flooded after a few decades. And if we take into account that various crops are grown in these territories, then huge damage will be done to agriculture, and this, in turn, can provoke an acute shortage of food.
Due to rising water levels in the world's oceans, many coastal cities may be flooded, and in the future even entire countries. As a result, people will simply have nowhere to live. Moreover, a real threat is already looming over some regions.
Under the influence of the high temperatures caused by the greenhouse effect, moisture evaporates much faster, and this has the most direct detrimental effect on the vegetation of the Earth. Reducing its volume will exacerbate problems and worsen the composition of the air. As a result, centuries later, a moment may come when there will be simply nothing to breathe on the planet.
Heat is a threat to the health of many people, especially those suffering from cardiovascular and endocrine diseases. Not for nothing in summer period mortality is on the rise all over the world.
Due to the greenhouse effect and the serious climatic changes caused by it, not only the flora of the planet, but also the fauna can suffer, that is animal world. Some of its representatives are already considered endangered, including due to.
Humanity is already experiencing the power of natural anomalies: heavy rainfall, hurricanes, floods, tsunamis, tornadoes, earthquakes and other phenomena that threaten people's lives.

How to avoid serious consequences

The problem of the greenhouse effect on Earth is very relevant, so many scientists are actively developing and thinking through solutions.

First, energy consumption should be completely reconsidered. It is advisable to abandon combustible natural fossils and solid fuel materials by switching to natural gas or alternative and still insufficiently developed natural sources, such as sun, water, wind.
Secondly, the greenhouse effect and its influence on the planet Earth will weaken if humanity pursues a policy of saving and saving energy. To do this, you can, for example, fully insulate houses and use building and finishing materials that retain heat. Also, in manufacturing and industrial enterprises, equipment should be installed that will reduce energy consumption.
Thirdly, one of the ways to combat the greenhouse effect can be the re-equipment of the transport system. It is not necessary to give up cars, but you can buy those that work without exhaust gases settling in the lower layers of the atmosphere, for example, on solar panels or electricity. The development of alternative sources is underway, but its results are not yet known.
Fourthly, it is necessary to restore forests on Earth, stop their cutting down, and plant new trees. And if every inhabitant of the planet makes a contribution, then this will already significantly affect the overall situation. In addition, it is worth reconsidering the cultivation of various crops, namely, abandoning chemical fertilizers and spraying poisons that pollute the atmosphere and enhance the greenhouse effect.
Fifth, we need to optimize the waste recycling system so as not to pollute the atmosphere and the planet. Industrial plants should have treatment facilities minimizing emissions. The waste itself must be fully disposed of or recycled and used as secondary raw materials. In addition, in order to reduce the number of landfills, completely degradable and harmless materials should be used in production.

Now the essence of the greenhouse effect and its influence on the atmosphere is clear to you, and you know why the planet is in danger. It is very difficult to eliminate such a phenomenon, but if all of humanity reconsiders its attitude towards the Earth and begins to act, then serious consequences can be avoided.

The mechanism of the greenhouse effect is as follows. The sun's rays, reaching the Earth, are absorbed by the soil surface, vegetation, water surface, etc. The heated surfaces give off thermal energy again to the atmosphere, but in the form of long-wave radiation.

Atmospheric gases (oxygen, nitrogen, argon) do not absorb thermal radiation from the earth's surface, but scatter it. However, as a result of burning fossil fuels and other production processes the atmosphere accumulates: carbon dioxide, carbon monoxide, various hydrocarbons (methane, ethane, propane, etc.), which do not scatter, but absorb thermal radiation coming from the Earth's surface. The screen that arises in this way leads to the appearance of the greenhouse effect - global warming.

In addition to the greenhouse effect, the presence of these gases causes the formation of the so-called photochemical smog. At the same time, as a result of photochemical reactions, hydrocarbons form very toxic products - aldehydes and ketones.

Global warming is one of the most significant consequences of anthropogenic pollution of the biosphere. It manifests itself both in climate change and in biota: the production process in ecosystems, the shift in the boundaries of plant formations, and changes in crop yields. Especially strong changes can affect high and middle latitudes. According to forecasts, it is here that the temperature of the atmosphere will increase most noticeably. The nature of these regions is especially susceptible to various impacts and is extremely slowly restored.

As a result of warming, the taiga zone will shift to the north by about 100-200 km. The rise in the ocean level due to warming (melting of ice and glaciers) can be up to 0.2 m, which will lead to the flooding of the mouths of large, especially Siberian, rivers.

The regular conference of the countries-participants of the Convention on Prevention of Climate Change, held in Rome in 1996, once again confirmed the need for coordinated international action to solve this problem. In accordance with the Convention, industrialized countries and countries with economies in transition have assumed obligations to stabilize the production of greenhouse gases. The countries that are members of the European Union have included in their national programs provisions to reduce carbon emissions by 20% by 2005

In 1997, the Kyoto (Japan) agreement was signed, under which developed countries pledged to stabilize greenhouse gas emissions at the 1990 level by 2000.

However, greenhouse gas emissions have even increased since then. This was facilitated by the US withdrawal from the Kyoto agreement of 2001. Thus, the implementation of this agreement was threatened with disruption, since the quota necessary for the entry into force of this agreement was violated.

In Russia, due to a general decline in production, greenhouse gas emissions in 2000 amounted to 80% of the 1990 level. Therefore, in 2004 Russia ratified the Kyoto agreement, giving it legal status. Now (2012) this agreement is in force, other states (for example, Australia) join it, but the decisions of the Kyoto Agreement remain unfulfilled. However, the struggle to implement the Kyoto agreement continues.

One of the most famous fighters against global warming is the former Vice President of the United States. A. Gore. After losing the 2000 presidential election, he dedicates himself to combating global warming. "Save the world before it's too late!" is its slogan. Armed with a set of slides, he traveled the world explaining the science and politics of global warming, the potential for serious consequences in the near future, if not limited by the rise in human-caused carbon dioxide emissions.

A. Gore wrote extensively famous book“Inconvenient truth. Global warming, how to stop a planetary catastrophe. In it, he confidently and rightly writes: “Sometimes it seems that our climate crisis is proceeding slowly, but in fact it is happening very quickly, becoming a truly planetary danger. And in order to defeat the threat, we must first recognize the fact of its existence. Why don't our leaders seem to hear such loud warnings of danger? They resist the truth, because at the moment of recognition they will face their moral duty - to act. Is it just much more convenient to ignore the danger warning? Perhaps, but an inconvenient truth does not disappear just because it is not seen.

In 2006, he was awarded the American literary prize. Based on the book was created documentary « The Inconvenient Truth" with A. Gore in leading role. The film in 2007 received an Oscar and was included in the rubric "Everyone Should Know This". In the same year, A. Gore (together with the IPCC expert group) was awarded Nobel Prize world for their work in environmental protection and research on climate change.

Currently, A. Gore is also actively continuing the fight against global warming, being a freelance consultant for the Intergovernmental Panel on Climate Change (IPCC), established by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP).

Global warming and greenhouse effect

Back in 1827, the French physicist J. Fourier suggested that the Earth's atmosphere acts as a glass in a greenhouse: air lets in solar heat, but does not allow it to evaporate back into space. And he was right. This effect is achieved due to some atmospheric gases, such as water vapor and carbon dioxide. They transmit visible and "near" infrared light emitted by the Sun, but absorb "far" infrared radiation, which is formed when the earth's surface is heated by the sun's rays and has a lower frequency (Fig. 12).

In 1909, the Swedish chemist S. Arrhenius for the first time emphasized the enormous role of carbon dioxide as a temperature regulator of the near-surface air layers. Carbon dioxide freely transmits the sun's rays to the earth's surface, but absorbs most of the thermal radiation of the earth. This is a kind of colossal screen that prevents the cooling of our planet.

The temperature of the Earth's surface is steadily increasing, having increased over the XX century. by 0.6 °C. In 1969 it was 13.99°C, in 2000 it was 14.43°C. Thus, the average temperature of the Earth at present is about 15 °C. At a given temperature, the surface of the planet and the atmosphere are in thermal equilibrium. Heated by the energy of the Sun and the infrared radiation of the atmosphere, the surface of the Earth returns an average equivalent amount of energy to the atmosphere. This is the energy of evaporation, convection, heat conduction and infrared radiation.

Rice. 12. Schematic image greenhouse effect caused by the presence of carbon dioxide in the atmosphere

Recently, human activity has introduced an imbalance in the ratio of absorbed and released energy. Before human intervention in global processes on the planet, changes occurring on its surface and in the atmosphere were associated with the content of gases in nature, which light hand scientists were called "greenhouse". These gases include carbon dioxide, methane, nitric oxide and water vapor (Fig. 13). Now anthropogenic chlorofluorocarbons (CFCs) have been added to them. Without the gas "blanket" enveloping the Earth, the temperature on its surface would be 30-40 degrees lower. The existence of living organisms in this case would be very problematic.

Greenhouse gases temporarily trap heat in our atmosphere, creating the so-called greenhouse effect. As a result of man-made human activities, some greenhouse gases increase their share in the overall balance of the atmosphere. This applies primarily to carbon dioxide, the content of which has been steadily increasing from decade to decade. Carbon dioxide creates 50% of the greenhouse effect, CFCs account for 15-20%, and methane accounts for 18%.

Rice. 13. The proportion of anthropogenic gases in the atmosphere with the greenhouse effect of nitrogen 6%

In the first half of the XX century. the content of carbon dioxide in the atmosphere was estimated at 0.03%. In 1956, within the framework of the first International Geophysical Year, scientists conducted special studies. The given figure was adjusted and amounted to 0.028%. In 1985, measurements were taken again, and it turned out that the amount of carbon dioxide in the atmosphere had increased to 0.034%. Thus, an increase in the content of carbon dioxide in the atmosphere is a proven fact.

Over the past 200 years, as a result of anthropogenic activities, the content of carbon monoxide in the atmosphere has increased by 25%. This is due, on the one hand, to the intensive combustion of fossil fuels: gas, oil, shale, coal, etc., and on the other hand, to the annual decrease in forest areas, which are the main sinks of carbon dioxide. In addition, the development of such agricultural sectors as rice growing and animal husbandry, as well as the growth of urban landfill areas, lead to an increase in the emission of methane, nitrogen oxide and some other gases.

Methane is the second most important greenhouse gas. Its content in the atmosphere increases by 1% annually. The most significant suppliers of methane are landfills, cattle, and rice fields. Gas reserves in landfills major cities can be considered as small gas fields. As for the rice fields, as it turned out, despite big exit methane, relatively little of it enters the atmosphere, since most of it is broken down by bacteria associated with the rice root system. Thus, the impact of rice agricultural ecosystems on the release of methane into the atmosphere is generally moderate.

Today there is no doubt that the trend towards the use of predominantly fossil fuels inevitably leads to global catastrophic climate change. At the current rate of coal and oil use, the next 50 years are projected to increase average annual temperature on the planet ranging from 1.5 °С (near the equator) to 5 °С (at high latitudes).

An increase in temperature as a result of the greenhouse effect threatens with unprecedented environmental, economic and social consequences. The water level in the oceans can rise by 1-2 m due to sea water and melting polar ice. (Due to the greenhouse effect, the level of the World Ocean in the 20th century has already risen by 10-20 cm.) It has been established that a 1 mm rise in sea level leads to a retreat of the coastline by 1.5 m.

If the sea level rises by about 1 m (and this is the worst scenario), then by 2100 about 1% of the territory of Egypt, 6% of the territory of the Netherlands, 17.5% of the territory of Bangladesh and 80% of the Majuro Atoll, which is part of the Marshal, will be under water - fishing islands. This will be the beginning of a tragedy for 46 million people. According to the most pessimistic forecasts, the rise in the level of the World Ocean in the XXI century. may entail the disappearance from the world map of countries such as Holland, Pakistan and Israel, the flooding of most of Japan and some other island states. St. Petersburg, New York and Washington may go under water. While some parts of the land are at risk of being at the bottom of the sea, others will suffer from the most severe drought. Disappearance threatens the Azov and Aral seas and many rivers. The area of deserts will increase.

A group of Swedish climatologists found that from 1978 to 1995 the area of floating ice in the Arctic Ocean decreased by about 610 thousand km2, i.e. by 5.7%. At the same time, it turned out that through the Fram Strait, which separates the Svalbard (Svalbard) archipelago from Greenland, up to 2600 km 3 of floating ice is annually carried into the open Atlantic at an average speed of about 15 cm / s (which is about 15-20 times more than the flow of such a river as Congo).

In July 2002, from the small island nation of Tuvalu, located on nine atolls in the southern part Pacific Ocean(26 km 2, 11.5 thousand inhabitants), there was a call for help. Tuvalu is slowly but surely sinking into the water - the most high point in the state rises only 5 m above sea level. In early 2004, the electronic media circulated a statement that expected high tidal waves associated with the new moon could raise sea levels in the area by more than 3 m for some time due to rising ocean levels due to global warming. If this trend continues, the tiny state will be washed off the face of the Earth. The government of Tuvalu is taking measures to resettle citizens in the neighboring state of Niue.

An increase in temperature will cause a decrease in soil moisture in many regions of the Earth. Droughts and typhoons will become commonplace. The ice cover of the Arctic will be reduced by 15%. In the coming century, the ice cover of rivers and lakes in the Northern Hemisphere will be 2 weeks less than in the 20th century. Ice melts in the mountains South America, Africa, China and Tibet.

Global warming will also affect the state of the world's forests. Forest vegetation, as is known, can exist within very narrow limits of temperature and humidity. Most of it may die, the complex ecological system will be at the stage of destruction, and this will entail a catastrophic decrease in the genetic diversity of plants. As a result of global warming on Earth in the second half of the XXI century. may disappear from a quarter to half of the species of land flora and fauna. Even under the most favorable conditions, by the middle of the century, the immediate threat of extinction will hang over almost 10% of the species of land animals and plants.

Studies have shown that in order to avoid a global catastrophe, it is necessary to reduce carbon emissions into the atmosphere to 2 billion tons per year (one third of the current volume). Given the natural population growth, by 2030-2050. per capita should be no more than 1/8 of the amount of carbon emitted today on average per inhabitant of Europe.

St. Petersburg College of Management and Economics

"Alexander Lyceum"

Report on the environmental fundamentals of nature management on the topic:

"Greenhouse effect"

Performed

group student №105

Vorozhbinova Sofia.

St. Petersburg, 2011

GREENHOUSE EFFECT

The greenhouse effect is a rise in temperature on the surface of the planet as a result of thermal energy that appears in the atmosphere due to the heating of gases. The main gases that lead to the greenhouse effect on Earth are water vapor and carbon dioxide.

The phenomenon of the greenhouse effect makes it possible to maintain a temperature on the Earth's surface at which the emergence and development of life is possible. If the greenhouse effect were absent, the average surface temperature of the globe would be much lower than it is now. However, as the concentration of greenhouse gases rises, the atmosphere's impermeability to infrared rays increases, which leads to an increase in the temperature of the Earth.

In 2007, the Intergovernmental Panel on Climate Change (IPCC) - the most authoritative international body that brings together thousands of scientists from 130 countries of the world - presented its Fourth Assessment Report, which contained generalized conclusions about past and current climate change, their impact on nature and humans , as well as possible measures to counteract such changes.

According to published data, from 1906 to 2005, the average temperature of the Earth rose by 0.74 degrees. In the next 20 years, the temperature increase, according to experts, will average 0.2 degrees per decade, and by the end of the 21st century, the Earth's temperature may increase from 1.8 to 4.6 degrees (such a difference in the data is the result of superimposing a whole range of models future climate, which took into account various scenarios for the development of the world economy and society).

climate change impacts:

1. Change in the frequency and intensity of precipitation.

In general, the climate on the planet will become more humid. But the amount of precipitation will not spread evenly across the Earth. In regions that already receive enough rainfall today, their fallout will become more intense. And in regions with insufficient moisture, dry periods will become more frequent.

2. Sea level rise.

During the 20th century, the average sea level rose by 0.1-0.2 m. According to scientists, in the 21st century, the sea level rise will be up to 1 m. In this case, coastal areas and small islands will be the most vulnerable. States such as the Netherlands, Great Britain, as well as the small island states of Oceania and the Caribbean will be the first to fall under the risk of flooding. In addition, high tides will become more frequent, and coastal erosion will increase.

3. Threat to ecosystems and biodiversity.

There are forecasts for the extinction of up to 30-40% of plant and animal species, as their habitat will change faster than they can adapt to these changes.

4. Melting glaciers.

The current glaciation of the Earth can be considered one of the most sensitive indicators of ongoing global changes. Satellite data show that since the 1960s there has been a decrease in the area of snow cover by about 10%. Since the 1950s, in the Northern Hemisphere, the sea ice area has decreased by almost 10-15%, and the thickness has decreased by 40%. According to forecasts by experts from the Arctic and Antarctic Research Institute (St. Petersburg), in 30 years the Arctic Ocean will completely open from under the ice during the warm period of the year.

According to scientists, the thickness of the Himalayan ice is melting at a rate of 10-15 m per year. At the current rate of these processes, two-thirds of the glaciers will disappear by 2060, and by 2100 all glaciers will have completely melted.
The accelerated melting of glaciers poses a number of immediate threats to human development. For densely populated mountainous and foothill areas, avalanches, flooding or, conversely, a decrease in the full flow of rivers, and as a result, a reduction in fresh water reserves, are of particular danger.

5. Agriculture.

The impact of warming on agricultural productivity is ambiguous. In some temperate areas, yields may increase with a small increase in temperature, but decrease with large changes in temperature. In tropical and subtropical regions, overall yields are projected to decline.

The worst hit could be inflicted on the poorest countries least prepared to adapt to climate change. According to the IPCC, by 2080 the number of people facing the threat of hunger could increase by 600 million, twice the number of people living in poverty today in sub-Saharan Africa.

6. Water consumption and water supply.

One of the consequences of climate change may be the lack of drinking water. In regions with arid climates (Central Asia, the Mediterranean, South Africa, Australia, etc.), the situation will be further aggravated due to a decrease in precipitation.
Due to the melting of glaciers, the flow of the largest waterways in Asia - the Brahmaputra, Ganges, Yellow River, Indus, Mekong, Salween and Yangtze - will significantly decrease. The lack of fresh water will affect not only human health and agricultural development, but will also increase the risk of political divisions and conflicts over access to water resources.

7. Human health.

Climate change, according to scientists, will lead to increased health risks for people, especially for the poorer segments of the population. Thus, a reduction in food production will inevitably lead to malnutrition and hunger. Abnormally high temperatures can exacerbate cardiovascular, respiratory and other diseases.

Rising temperatures may change the geographic distribution of various disease vector species. As temperatures rise, the ranges of heat-loving animals and insects (such as encephalitic mites and malaria mosquitoes) will spread further north, while the people inhabiting these areas will not be immune to new diseases.

According to environmentalists, humanity is unlikely to be able to prevent completely predictable climate change. However, it is in human power to mitigate climate change, to restrain the rate of temperature increase in order to avoid dangerous and irreversible consequences in the future. First of all, due to:

1. Restrictions and reductions in the consumption of fossil carbon fuels (coal, oil, gas);
2. Improving the efficiency of energy consumption;
3. Implementation of energy saving measures;
4. Greater use of non-carbon and renewable energy sources;
5. Development of new environmentally friendly and low-carbon technologies;
6. Through the prevention of forest fires and the restoration of forests, since forests are natural sinks of carbon dioxide from the atmosphere.

The greenhouse effect takes place not only on Earth. A strong greenhouse effect is on the neighboring planet, Venus. The atmosphere of Venus is almost entirely composed of carbon dioxide, and as a result, the surface of the planet is heated to 475 degrees. Climatologists believe that the Earth avoided such a fate due to the presence of oceans on it. The oceans absorb atmospheric carbon and it accumulates in rocks such as limestone, thereby removing carbon dioxide from the atmosphere. There are no oceans on Venus, and all the carbon dioxide emitted into the atmosphere by volcanoes remains there. As a result, an uncontrollable greenhouse effect is observed on the planet.

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