Problems of greenhouse gas accumulation in the atmosphere. Greenhouse effect - causes and consequences. The accumulation of which gases enhances the greenhouse effect

Greenhouse gases are gases that trap infrared rays that warm the Earth's surface and atmosphere. The most important greenhouse gases are water vapor, carbon dioxide, methane, nitrogen oxide, ozone, and freons. Greenhouse gases can be of natural (natural) or anthropogenic origin. Accordingly, one should distinguish between the natural greenhouse effect and the contribution to the greenhouse effect due to gases released into the atmosphere as a result of human activity. Carbon dioxide (CO2) is the main anthropogenic greenhouse gas. About 80% of carbon dioxide comes from burning fossil fuels, the rest comes from deforestation, primarily tropical forests. Nitric oxide (N20) is formed by the combustion of fossil fuels, biomass, and the use of fertilizers.[...]

GREENHOUSE EFFECT (GREENHOUSE EFFECT) - warming of the Earth's climate as a result of an increase in the content in the ground layer of the atmosphere of dust, carbon dioxide, methane and fluorochlorocarbon compounds of technical origin (fuel combustion, industrial emissions, etc.), which prevent long-wave thermal radiation from the surface of the Earth. The mixture of dust and gases acts like a plastic film over a greenhouse: it transmits well sunlight, going to the soil surface, but retains the heat dissipated by the soil - as a result, a warm microclimate is created under the film.[...]

The greenhouse effect is as follows; Carbon dioxide promotes the penetration of short-wave radiation from the Sun to the Earth, and the long-wave thermal radiation of the Earth is delayed. As a result, prolonged heating of the atmosphere occurs.[...]

Greenhouse effect - heating of the surface layer of the atmosphere caused by the absorption of long-wave (thermal) radiation earth's surface. The main reason This process is the enrichment of the atmosphere with gases that absorb thermal radiation. The most important role here is played by the increase in carbon dioxide (CO2) content in the atmosphere.[...]

The greenhouse effect is a decrease in the Earth's thermal radiation due to an increase in the content of carbon dioxide in its atmosphere. Carbon dioxide freely transmits short-wave solar radiation, but blocks heat rays coming from the heated earth's surface. An increase in the concentration of carbon dioxide leads to a disruption in the energy balance of the planet and its overheating.[...]

The greenhouse effect is understood as a possible increase in the global temperature of the planet as a result of changes in the heat balance caused by the gradual accumulation of greenhouse gases in the atmosphere. [...]

The essence of the greenhouse effect is as follows. The sun's rays penetrate through the earth's atmosphere to the surface of the earth. However, the accumulation in the atmosphere of carbon dioxide, nitrogen oxides, methane, water vapor, and fluorochlorine hydrocarbons (freons) leads to the fact that the Earth's thermal long-wave radiation is absorbed by the atmosphere. This leads to the accumulation of excess heat in the surface layer of air, i.e. the thermal balance of the planet is disrupted. This effect is similar to what we observe in greenhouses covered with glass or film. As a result, the air temperature at the earth's surface may increase.[...]

The main greenhouse gas is carbon dioxide (Table 7.5). 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, CFCs (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 action per molecule. If according to this indicator CO2 is taken as one, then for methane it will be equal to 25, for nitrogen oxides - 165, and for freon - 11000. [...]

GREENHOUSE EFFECT. See greenhouse effect (atmosphere).[...]

Main part The greenhouse effect is determined by water vapor present in the atmosphere and unevenly distributed in it, partially condensed in the clouds. About 10% of the greenhouse effect is provided by carbon dioxide evenly distributed in the atmosphere, the content of which is 16 times less than water vapor. The remaining gases in the atmosphere (among which the main one is methane, which has a concentration almost two orders of magnitude lower than the concentration of carbon dioxide) determine less than 1% of the greenhouse effect.[...]

The term “greenhouse effect” refers to a specific phenomenon. Solar radiation falling on the Earth is partially absorbed by the surface of land and ocean, and 30% of it is reflected into outer space. A “clean” atmosphere is transparent to infrared radiation, and an atmosphere containing vapors of triatomic (greenhouse) gases (water, carbon dioxide, sulfur oxides, etc.) absorbs infrared rays, causing the air to heat up. Therefore, greenhouse gases perform the function of glass coating in conventional garden greenhouses.[...]

Ozone (Oz) is an important greenhouse gas found in both the stratosphere and troposphere. It affects both short-wave and long-wave radiation, and therefore the final direction and magnitude of its contribution to the radiation balance strongly depends on the vertical distribution of ozone content, especially at the tropopause level, where reliable observations are still lacking. Therefore, determining the contribution of ozone to the greenhouse effect is more difficult compared to well-mixed gases. Estimates indicate a positive resultant (approximately +0.4 watt/m).[...]

This slowdown in energy expansion came as a complete surprise to analysts who overlooked an extremely important fact: over the past 25 years, all developed countries of the world have stopped increasing their per capita consumption of all types of fuel combined. This undoubtedly affected the dynamics of global energy consumption, which has a clear tendency to stabilize at the level of 2.5 t.e. per year per person. In our opinion, this is due to the fading trend of the demographic explosion, which began in 1988 (the same year saw the maximum energy consumption per capita).[...]

Another gas that creates a greenhouse effect on the planet is methane. The increase in its concentration in the air was confirmed experimentally by analyzing gas bubbles in polar ice(Fig. 9.4, b). The main natural reason for the formation of methane is the activity of special bacteria that decompose carbohydrates under anaerobic conditions (without oxygen access). This occurs primarily in swamps and in the digestive tract of animals. Methane is produced in compost piles, landfills, rice paddies (anywhere water and dirt keep plant debris away from the air), and from fossil fuel extraction.[...]

The most significant natural greenhouse gases are water vapor, which is contained in large quantities in the atmosphere, as well as carbon dioxide, which enters the atmosphere both naturally and artificially and is the main component causing the greenhouse effect of anthropogenic origin. It is known that in the absence of carbon dioxide in the atmosphere, the temperature of the Earth's surface would be approximately 3.3 degrees lower than at present, which would create extremely unfavourable conditions for the life of animals and plants.[...]

Nobody disputes today that the “greenhouse effect” is increasing. However, projections regarding the impact of warming on ecological system-.planets are not clear-cut.[...]

To understand the nature and mechanism of the greenhouse effect, it is also important to know that the contribution of the same component to the total flux of radiation strongly depends on its distribution in the atmosphere. Let us illustrate this using the example of the three main “greenhouse” gases - water vapor, ozone and CO2. From Fig. 3.1 it is clear that the absorption band of the carbon dioxide molecule centered at 15 μm is largely overlapped by the bands of water vapor. From here we could conclude that that the role of CO2 in the absorption of radiation is not so great. However, if we turn to Fig. 3.3, which shows the vertical profiles of H, 0 and 03 obtained during real observations in January 1972, we will see how large the concentration gradient is. water vapor. On the contrary, carbon dioxide is quite uniformly mixed in the air layer from about 1 to 70 km. Therefore, above 2-3 km, the main absorber of the rising thermal radiation of the underlying surface may be CO2, and this conclusion is supported by the calculation results presented in Table 3.2. [...]

Vronsky V.A. Ecological consequences of the greenhouse effect // Biology in school. - 1993. - No. 3. - P. 15-17.[...]

Unlike the global impact of greenhouse gases, the effect of atmospheric aerosols is local. The geographic distribution of sulfate aerosols in the air largely coincides with industrial areas of the world. It is there that the local cooling effect of aerosols can significantly reduce and even virtually eliminate the global greenhouse effect.[...]

Methane is the second most abundant greenhouse gas and is currently estimated at 20-25%. The contribution of carbon dioxide to the greenhouse effect is 43%, freon - 14%, nitrous oxide - 5%, other gases (carbon fluorochloride, tropospheric ozone, etc.) - 13%. [...]

It must be borne in mind that the accuracy of estimates of both the greenhouse effect as a whole and its components is still not absolute. It is unclear, for example, how one can accurately take into account the greenhouse role of water vapor, which, when clouds appear, becomes a powerful factor in increasing the Earth’s albedo. Stratospheric ozone is not so much a greenhouse gas as it is an anti-greenhouse gas, as it reflects approximately 3% of incoming solar radiation. Dust and other aerosols, especially sulfur compounds, reduce the heating of the earth's surface and lower atmosphere, although they play the opposite role for the heat balance of desert areas. [...]

It should be noted that the phenomenon now called the greenhouse effect of gaseous atmospheric impurities was first pointed out in 1824 by the French scientist J. Fourier, and in 1861 the English physicist J. Tyndall discovered that, like water vapor, CO2 molecules screen infrared radiation. This geophysical property of carbon dioxide is not, however, its only global lever of influence on the biosphere. Other comparable qualities of CO2, such as fertilizing and anti-transpiration effects, are discussed in the chapter “Living Matter”. Let's return to the main topic.[...]

Currently, about 10% of the land is covered with ice. The approximation of the greenhouse effect depends on the amount of carbon dioxide emissions.[...]

Some gases in the atmosphere, including water vapor, have a greenhouse effect, that is, the ability to transmit solar radiation to a greater extent to the Earth's surface compared to thermal radiation emitted by the Earth heated by the Sun. As a result, the temperature of the Earth's surface and the ground layer of air is higher than it would be in the absence of the greenhouse effect. The greenhouse effect is one of the life support mechanisms on Earth.[...]

The combination of the first two factors is called “Relative greenhouse potential” and is expressed in units of CO2 potential. It is a convenient indicator current state greenhouse effect and is used in international diplomatic negotiations. The relative role of each greenhouse gas is very sensitive to changes in each factor and to their interdependence, and is therefore determined very approximately.[...]

The basis for the construction of supporters of the greenhouse effect is climate monitoring. The number of warming over 100 years of 0.5-0.6 degrees Celsius is often mentioned. But the climate reports cited above make it clear that “all types of data used to study climate change and variability suffer from problems of quality and inadequacy.” Another alarming fact is that since the beginning of satellite observations (late 70s of the last century), global changes in tropospheric temperature have hardly been observed. According to satellite and radiosonde data, during this period the global temperature in the lower and middle troposphere remained almost unchanged: its increase was only 0.05 degrees Celsius per decade, which is half the error of this estimate (± 0.1 degrees per 10 years). In the upper troposphere, since the beginning of the 60s of the last century, no statistically significant global temperature trends have been observed at all. [...]

Let us also note the following important circumstance: it is, in principle, hardly possible to reliably record the greenhouse effect of anthropogenic origin with a small number of observations, since the amount of heat required to heat the atmosphere, say, by 1 degree, is three orders of magnitude less than the amount of heat lost to space space due to radiation from the upper layers of the atmosphere.[...]

Just two or three decades ago, only environmental scientists knew about global warming due to the greenhouse effect. Today this has become a problem that concerns humanity.[...]

Carbon dioxide, or carbon dioxide (CO2), differs, in comparison with other greenhouse gases, by a relatively low potential of the greenhouse effect, but by a rather significant duration of existence in the atmosphere - 50-200 years and a relatively high concentration. The share of carbon dioxide in the greenhouse effect is currently about 64%, but this relative value is unstable because it depends on the changing role of other greenhouse gases. [...]

The content of carbon dioxide and methane in the atmosphere is growing rapidly. These gases cause the “greenhouse effect” (Fig. 13.4).[...]

According to Russian, French and American researchers, the level of gases that create the greenhouse effect in the Earth's atmosphere is currently the highest in the last 420 thousand years. The research was carried out at the Russian Antarctic base "Vostok", where, by drilling through the ice, researchers reached a record depth of 3620 m, which corresponds to a layer formed 420 thousand years ago. Air bubbles contained in the ice have become a kind of archive of the state of the atmosphere. During global warming the level of gases causing the greenhouse effect (carbon dioxide, methane, etc.) increased, and during cold weather - decreased.[...]

And we are threatened not only by a lack of energy, but also by heat death from excess heat generated when receiving it (the so-called “greenhouse effect”).[...]

However, about 3 billion years ago, the amount of atmospheric carbon dioxide began to decrease due to its binding in carbonate rocks. The greenhouse effect had decreased so much by 2.8 billion years that continental glaciation occurred. This was the first (?) glacioera in the history of the Earth. The average global temperature, according to V.A. Zubakov, did not exceed 4-10°C at that time. Subsequently, the luminosity of the Sun increased, and the greenhouse effect of radiation-active gases and gaseous substances the atmosphere began to decrease, but this process proceeded in fits and starts.[...]

Instrumentally proven accumulation in the atmosphere of carbon dioxide by 0.4% in gas, methane by 1% and nitrogen oxide L/0 by 0.2%. which causes the "greenhouse effect". It consists in the fact that these gases, entering the atmosphere, impede the transfer of heat from the surface of the Earth and act like a stack or film in a greenhouse. [...]

The goal of the United Nations Framework Convention on Climate Change is to stabilize concentrations of greenhouse gases in the atmosphere at levels that would cause dangerous imbalances in the global climate system. This will require us to reduce emissions of gases such as carbon dioxide by-product use of fuel for energy production.[...]

Chlorofluorocarbons (CFCs) are substances synthesized by humans that contain chlorine, fluorine and bromine. They have a very strong relative greenhouse potential and a significant atmospheric lifespan. Their total role in the greenhouse effect was, in the mid-1990s, approximately 7%. The production of chlorofluorocarbons in the world is currently controlled by international agreements on the protection of the ozone layer, which include a provision for a gradual reduction in the production of these substances, replacing them with less ozone-depleting ones, followed by its complete cessation. As a result, the concentration of CFCs in the atmosphere began to decrease.[...]

It was noted above what negative consequences can result from an intensive increase in the content of carbon dioxide in the atmosphere due to the greenhouse effect (climate warming, melting glaciers, rising sea levels, etc.). In addition, an increase in carbon dioxide concentration increases the decomposition of building materials - limestone, dolomite, concrete, stone. Some ancient monuments, having survived millennia, cannot survive the disease caused by pollution environment. The same nitric acid, formed by the interaction of nitrogen oxides and water, has a destructive effect on them. [...]

The role of the atmosphere in life is great: maintaining respiration processes (oxygen), transporting gaseous substances - the basis of life of plant organisms and regulating temperature on earth (“greenhouse effect”).[...]

In 1896, S. Arrhenius (1859-1927) published a seminal work in which he quantified the effect of changes in atmospheric CO2 concentration on the temperature of the earth's surface. In calculating the greenhouse effect, he took into account the effect of an important positive feedback between rising temperatures and increasing water vapor content in the air, which should also lead to climate warming.[...]

By the middle of the 21st century (2050), CO2 concentrations in the Earth's atmosphere can be expected to double compared to the time before industrialization (approximately 1850). Thus, there is undoubtedly a threat of the anthropogenic greenhouse effect when burning fossil fuels.[...]

The climate can be characterized by some average global temperature of the surface layer of the atmosphere and the level of the World Ocean. Currently, an increase in these parameters is interpreted as global warming caused by the anthropogenic greenhouse effect (due to the emission of carbon dioxide due to the combustion of carbon-containing fuels). However, if the heat and water balances of the planet are unstable, then the assumptions about the constancy of global temperature and sea level turn out to be incorrect, and these quantities are always in a non-stationary state, changing in a complex way. [...]

The global level of environmental safety management involves forecasting and monitoring processes in the state of the biosphere as a whole and its constituent spheres. In the second half of the 20th century. these processes are expressed in global changes climate, the emergence of the “greenhouse effect”, destruction ozone screen, desertification of the planet and pollution of the World Ocean. The essence of global control and management is the preservation and restoration of the natural mechanism of reproduction of environmental conditions by the biosphere, which is directed by the totality of those that make up the biosphere living organisms.[ ...]

However, the enormous power developed by the Earth's biota harbors a hidden danger of rapid destruction of the environment. If the integrity of the biota is violated, the environment can be completely distorted over decades. It is known that the concentration of carbon dioxide (CO2) in the atmosphere is rapidly increasing, which enhances the greenhouse effect and can lead to an increase in surface temperature (global warming). This process has long been associated only with the combustion of fossil fuels. However, global land use analysis shows that in large areas of the continental biosphere the amount organic carbon does not increase, but decreases, and the rate of carbon emission from continental biota and organic soil reserves coincides in order of magnitude with the rate of fossil carbon emission from the combustion of coal, oil and gas. Consequently, modern biota violates Le Chatelier's principle. Since the beginning of this century, land biota has ceased to absorb excess carbon dioxide from the atmosphere. Instead, it began releasing carbon into the atmosphere, increasing rather than decreasing industrial pollution. This means that the structure of the natural terrestrial biota has been disrupted on a global scale.[...]

Let's see why this ironclad theory is not suitable for garden houses. So, you have made a foundation of concrete blocks, planting it below the calculated freezing depth of the soil. In the Moscow region, for example, such a depth is 1.5 m, however, 1.4, even 1.3 m is enough: for many years now, winters in the Moscow region, and, perhaps, everywhere have been much warmer than in those days this design depth was established. Further, they say, it will be even warmer due to the greenhouse effect from the high content of CO2 in the atmosphere.[...]

To preserve the Earth's ozone layer, measures are being taken to reduce emissions of freons and replace them with environmentally friendly substances. Currently, solving the problem of preserving the ozone screen and destroying ozone holes is necessary to preserve earthly civilization. The United Nations Conference on Environment and Development, held in Rio de Janeiro, concluded that our atmosphere is increasingly affected by greenhouse gases that threaten climate change, as well as chemical substances, reducing ozone layer.[ ...]

If measures are not taken, the accumulation of CO2 will lead to the accumulation of heat in the lower layers of the troposphere (since CO2 does not transmit heat rays emitted by the Earth). Along with colossal (up to 3x14 MJ per year) energy releases from heat sources, this can lead to heating of the atmosphere, melting of ice, increased humidity, isolation from the Sun, cooling, etc. At the end of this chain, a flood followed by an ice age is not excluded. This mechanism, often called the “greenhouse effect” hypothesis, is confirmed by multiparameter computer calculations. Scientists believe that the process has already begun: 1987 is the warmest in terms of average global temperature, winter 1989 is the hottest, 80s. - the warmest decade. Global warming of just 2-3 degrees could have dramatic consequences.[...]

As a result of rapid technogenic activity, thoughtless attitude towards the environment, uncontrolled scientific and technological progress, increased pressure on nature, predatory use natural resources The Earth is clearly visible emerging global ecological problems, components of the general environmental crisis: pollution of the atmosphere, geodrosphere, lithosphere by harmful technogenic waste; climate change, primarily its warming due to the “greenhouse effect”, with the subsequent possibility of flooding of large populated areas; destruction of the ozone layer in the atmosphere and the emergence of the danger of exposure to short-wave ultraviolet (UV) radiation, which is destructive for all life on Earth; depletion of material and natural resources; destruction of forests, formation of deserts; impoverishment biological species flora and fauna; growth of the planet's population and provision of food, housing, and clothing; spread of viral incidence among regions; violation of the genetic integrity of landscapes; aesthetic and ethical aspects environmental degradation natural environment; discrepancy between the restorative abilities of nature and technogenic impact, etc.[...]

Thermal equilibrium occurs when the temperatures of the bodies involved in heat exchange become the same, i.e. each of them begins to give away as much energy as it receives from other bodies. Therefore, in winter, for example, when the surface of the Earth emits more energy into space than it receives from the Sun, its temperature begins to decrease. In summer the opposite phenomenon occurs. This also explains the fact that on a cloudless night the temperature drops more than on a cloudy night. In the latter case, part of the Earth's radiation is reflected by clouds onto its surface. Less cloudiness is also responsible for the relatively sharp drop in temperature at night in mountainous areas compared to flat ones. The presence in the atmosphere of impurity gases of anthropogenic origin with molecular sizes larger than those of its main components (nitrogen, oxygen) (CC>2, CH4, SO2, etc.) reduces infrared radiation into space. This may contribute to the development of the “greenhouse” effect (section 1.6.1).[...]

The surface layer of the troposphere is most affected by anthropogenic impact, the main type of which is chemical and thermal air pollution. Air temperature is most strongly influenced by the urbanization of the territory. Temperature differences between an urbanized area and the surrounding undeveloped areas are associated with the size of the city, building density, and synoptic conditions. There is a tendency for temperature to rise in every small and big city. For large cities in the temperate zone, the temperature contrast between the city and the suburbs is 1-3° C. In cities, the albedo of the underlying surface (the ratio of reflected radiation to total radiation) decreases as a result of the appearance of buildings, structures, and artificial surfaces; here solar radiation is more intensively absorbed and accumulated by structures buildings absorb heat during the day with its release into the atmosphere in the evening and at night. The heat consumption for evaporation is reduced, as the open areas are reduced soil cover occupied by green spaces, and the rapid removal of precipitation by rainwater drainage systems does not allow the creation of moisture reserves in soils and surface water bodies. Urban development leads to the formation of zones of air stagnation, which leads to its overheating; the transparency of the air in the city also changes due to the increased content of impurities in it from industrial enterprises and transport. In the city, the total solar radiation decreases, as well as counter infrared radiation from the earth’s surface, which, together with the heat transfer of buildings, leads to the appearance of a local “greenhouse effect”, i.e. the city is “covered” with a blanket of greenhouse gases and aerosol particles. Under the influence of urban development, the amount of precipitation changes. The main factor for this is a radical reduction in the permeability of the underlying surface to sediments and the creation of networks to drain surface runoff from the city. The huge amount of hydrocarbon fuel burned is of great importance. On the territory of the city in warm times there is a decrease in absolute humidity values ​​and the opposite picture in cold times - within the city the humidity is higher than outside the city.

The problem of the greenhouse effect is especially relevant in our century, when we are destroying forests to build another industrial plant, and many of us cannot imagine life without a car. We, like ostriches, bury our heads in the sand, not noticing the harm from our activities. Meanwhile, the greenhouse effect is increasing and leading to global disasters.

The phenomenon of the greenhouse effect has existed since the appearance of the atmosphere, although it was not so noticeable. Nevertheless, its study began long before the active use of cars and.

Brief Definition

The greenhouse effect is an increase in the temperature of the planet's lower atmosphere due to the accumulation of greenhouse gases. Its mechanism is as follows: the sun's rays penetrate the atmosphere and heat the surface of the planet.

Thermal radiation that comes from the surface should return to space, but the lower atmosphere is too dense for them to penetrate. The reason for this is greenhouse gases. Heat rays linger in the atmosphere, increasing its temperature.

History of greenhouse effect research

People first started talking about the phenomenon in 1827. Then an article by Jean Baptiste Joseph Fourier appeared, “A Note on the Temperatures of the Globe and Other Planets,” where he detailed his ideas about the mechanism of the greenhouse effect and the reasons for its appearance on Earth. In his research, Fourier relied not only on his own experiments, but also on the judgments of M. De Saussure. The latter conducted experiments with a glass vessel blackened from the inside, closed and placed in sunlight. The temperature inside the vessel was much higher than outside. This is explained by the following factor: thermal radiation cannot pass through the darkened glass, which means it remains inside the container. At the same time, sunlight easily penetrates through the walls, since the outside of the vessel remains transparent.

Several formulas

The total energy of solar radiation absorbed per unit time by a planet with radius R and spherical albedo A is equal to:

E = πR2 ( E_0 over R2) (1 – A),

where E_0 is the solar constant, and r is the distance to the Sun.

In accordance with the Stefan-Boltzmann law, the equilibrium thermal radiation L of a planet with radius R, that is, the area of ​​the emitting surface is 4πR2:

L=4πR2 σTE^4,

where TE is the effective temperature of the planet.

Causes

The nature of the phenomenon is explained by the different transparency of the atmosphere for radiation from space and from the surface of the planet. For the sun's rays, the planet's atmosphere is transparent, like glass, and therefore they easily pass through it. And for thermal radiation, the lower layers of the atmosphere are “impenetrable”, too dense for passage. That is why part of the thermal radiation remains in the atmosphere, gradually descending to its lowest layers. At the same time, the amount of greenhouse gases thickening the atmosphere is growing.

Back in school we were taught that the main cause of the greenhouse effect is human activity. Evolution has led us to industry, we burn tons of coal, oil and gas, producing fuel. The consequence of this is the release of greenhouse gases and substances into the atmosphere. Among them are water vapor, methane, carbon dioxide, and nitric oxide. It’s clear why they are named like that. The surface of the planet is heated by the sun's rays, but it necessarily “gives” some of the heat back. Thermal radiation that comes from the Earth's surface is called infrared.