The main reason for the impact on climate is considered to be an increase in the share of greenhouse gases in the atmosphere, leading to an increase in temperature, followed by the melting of glaciers and rising sea levels, which will cause dramatic climate change in the world. Over 130 years, from 1860 to 1990, the average global atmospheric temperature increased by 1 °C and this trend continues to the present day

The idea of ​​the greenhouse effect was first expressed by J. B. Fourier in 1827. According to him, the atmosphere is like a transparent glass shell, allowing sunlight to penetrate to earth's surface, but delaying the hidden radiation of the Earth.

Essence greenhouse effect is as follows: greenhouse gases act like glass, resulting in heat being concentrated under the shell they create around the earth. Light energy, penetrating through the atmosphere, is absorbed by the surface of our planet, turns into thermal energy and is released in the form of heat. Heat, as is known, unlike light, does not come out through the glass, but accumulates inside the greenhouse, significantly increasing the air temperature and increasing evaporation. The main absorber of thermal radiation from the Sun and the earth's surface is water, present in the form of vapors and clouds. Less than 7% of the radiation emitted by the earth's surface passes through "transparency windows", but these windows are significantly reduced due to the presence of molecules in the atmosphere greenhouse gases.

Greenhouse gases

Methane. Methane (CH 4) accounts for 12% of global warming. It is formed during the process of anaerobic bacterial decomposition in swamps, rice fields and landfills, in the stomachs of cows and sheep and in the intestines of termites, leaks from gas wells, gas pipelines, furnaces, furnaces. Over the past decades, methane content has increased due to an increase in areas occupied by rice, as well as as a result of the creation of large livestock farms. Methane persists in the troposphere for about 11 years. Each CH 4 molecule contributes greenhouse effect 25 times more than a CO 2 molecule. Methane emissions are increasing by 1% per year.

Nitrous oxide. Nitrous oxide (N 2 O) accounts for 6% of global warming. It is released during the decomposition of nitrogen fertilizers in soils, from wastewater from livestock farms, and during the combustion of biomass. It persists in the troposphere for an average of 150 years. Every molecule N 2 O is 230 times more effective in contributing to global warming than the CO 2 molecule. Emissions increase by 0.2% annually.

As a result of warming, something irreparable can happen to the fate of our planet: the melting of the glaciers of Greenland, North Arctic Ocean, South Pole, finally, mountain glaciers; The level of the World Ocean will rise significantly (by 1.5 -2 m or more). The average temperature of Antarctica will increase by 5 ° C, which is enough to melt the entire ice cap. The level of the World Ocean will rise everywhere by 4.5-8 m and many coastal areas will be flooded (Shanghai, Cairo, Venice, Bangkok, large areas fertile lowlands in India), and millions of people will be forced to migrate inland to mountainous regions; The influence of the ocean on land will increase through increased storms, high tides, and low tides. Equalization of temperatures at the equator and poles will lead to disruption of the existing atmospheric circulation, changes in precipitation patterns (poor rainfall in agricultural areas), and a decrease in the production of grain, meat and other food products. There is little hope for irrigation in these areas, since today the groundwater level has noticeably decreased, and by the middle of the century its reserves will be practically used up. The influence of the “greenhouse effect” on the regional climate is already beginning to manifest itself: long-term droughts in South Africa(5 years), North America (6 years), warm winters etc.

Carbon dioxide. Intensive deforestation, burning of fuel and garbage very noticeably upsets the existing balance carbon dioxide in the atmosphere. Each carbon atom of the fuel attaches two oxygen atoms during combustion to form carbon dioxide, so the mass of carbon dioxide increases compared to the mass of the fuel burned (1 kg of fuel → 3 kg of CO 2). Currently, this gas is responsible for intense warming of 57%. Every year CO 2 emissions increase by 4%.

CFCs(PCA, or CFC). The content of CFCs in the atmosphere is small compared to CO 2, but they have a fairly high heat capacity: they absorb heat much more intensely (50 times higher) than carbon dioxide. These gases account for 25% global warming. The main sources are leaks from air conditioners, evaporation from aerosol sprays. CFCs can remain in the atmosphere for 22-111 years depending on their type. CFC emissions are increasing by 5% annually.

Industrial production of fluorochlorocarbons, often called freons, began in the mid-1930s. Largest quantity Freon-11 (СFC1 3) and Freon-12 (СF 2 С1 2) were used as blowing agents in the production of porous polymer materials, fillers in aerosol packaging, as well as refrigerants in refrigerators and air conditioners. Some CFCs were used as degreasing agents: freon-113 (C 2 F 3 C1 3) and freon-114 (C 2 F 4 C1 2). Later, the above freons, due to their high chlorine content, were replaced by СНС1Р 2, which destroys ozone to a lesser extent, but to a greater extent absorbs IR rays and has a particularly active effect on the greenhouse effect during its stay in the troposphere.

What are freons

In 1931, when a refrigerant, freon, harmless to the human body was synthesized. Subsequently, more than four dozen different freons were synthesized, differing from each other in quality and chemical composition. The cheapest and most effective were R-11, R-12, which satisfied everyone for a long time. In the last 15 years, they have fallen out of favor due to their ozone-depleting properties. All freons are based on two gases - methane CH 4 and ethane - CH 3 -CH 3. In refrigeration technology, methane is graded R-50, ethane is graded R-70. All other freons are obtained from methane and ethane by replacing hydrogen atoms with chlorine and fluorine atoms. For example, R-22 is obtained from methane by replacing one hydrogen atom with chlorine and two with fluorine. The chemical formula of this freon is CHF 2 Cl. The physical qualities of refrigerants depend on the content of three components - chlorine, fluorine and hydrogen. So, as the number of hydrogen atoms decreases, the flammability of refrigerants decreases, and stability increases. They can exist in the atmosphere for a long time without decomposing and causing harm to the environment. As the number of chlorine atoms increases, the toxicity of refrigerants and their ozone-depleting ability increases. The harm caused by freons to the ozone discharge is assessed by the dose of ozone depletion potential, which is equal to 0 for ozone-safe refrigerants (R-410A, R-407C, R-134a) and up to 13 ozone-depleting (R-10, R-110). At the same time, the ozone-depleting potential of freon R-12, until recently the most widespread throughout space, was taken into account. In the property of the temporary task R-12, freon R-22 was chosen, the ozone depletion potential of which is 0.05. In 1987, the Montreal Protocol was adopted, limiting the use of ozone-depleting substances. In particular, according to this act, the culprits will be forced to abandon the use of R-22 freon, which currently powers 90% of all air conditioners. In most European countries, the sale of air conditioners using this freon will be stopped in 2002-2004. And many unprecedented models are already supplied to Europe only with ozone-safe refrigerants - R-407C and R-410A.

If the accumulation of “greenhouse gases” in the atmosphere is not interrupted, then in the second half of this century their concentration will approximately double, which will lead (according to computer models) to climate warming in different areas by an average of 1.5 - 4.5 ° C: in cold areas by 10 ° C, and in tropical areas - by only 1 - 2 ° C.

As a result of warming, something irreparable can happen to the fate of our planet: the glaciers of Greenland, the Arctic Ocean, the South Pole, and finally mountain glaciers will begin to melt; The level of the World Ocean will rise significantly (by 1.5 -2 m or more). The average temperature of Antarctica will increase by 5 "C, which is enough to melt the entire ice cap. The level of the World Ocean will rise everywhere by 4.5-8 m and many coastal areas will be flooded (Shanghai, Cairo, Venice, Bangkok, large areas of fertile lowlands will be flooded in India), and millions of people will be forced to migrate inland to mountainous areas; the influence of the ocean on land will increase through increased storms, tides, and ebbs. The equalization of temperatures at the equator and poles will lead to a disruption of the existing atmospheric circulation and a change in precipitation patterns (scanty precipitation). in agricultural areas), a decrease in the production of grain, meat and other food products. There is little hope for irrigation of these territories, since today the groundwater level has noticeably decreased, and by the middle of the century their reserves will be practically used up. The influence of the “greenhouse effect” on the regional climate. is already beginning to appear: long droughts in South Africa (5 years), North America (6 years), warm winters, etc.

With general warming, winters will be colder than before and summers will be hotter. In addition, droughts, floods, hurricanes, tornadoes and other weather and climate anomalies will become more frequent and severe. Warming will be accompanied by a decrease in bioproductivity and the spread of pests and diseases.

Useful materials and articles for installers of air conditioning and ventilation systems →

The impact of refrigerants on ozone depletion and global warming →

Greenhouse gases



The main greenhouse gas is water vapor (H 2 O), which is responsible for approximately two-thirds of the natural greenhouse effect. Other major greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and fluorinated greenhouse gases. These gases are regulated by the Kyoto Protocol.

CFCs and HCFCs are also greenhouse gases, but are regulated by the Montreal rather than the Kyoto Protocol.

Stratospheric ozone is itself a greenhouse gas. Thus, ozone depletion served to mitigate some aspects of climate change, while restoration of the ozone layer would add to climate change.

Carbon dioxide

The main participant in the enhancement of the (artificial) greenhouse effect is carbon dioxide (CO 2). In industrialized countries, CO 2 represents more than 80% of greenhouse gas emissions.

Currently, the world emits more than 25 billion tons of carbon dioxide every year. CO 2 /sub> can remain in the atmosphere from 50 to 200 years, depending on how it is returned to the earth and oceans.

Methane

The second most important greenhouse gas for enhancing the greenhouse effect is methane CH4. Since the beginning of the Industrial Revolution, atmospheric methane concentrations have doubled and contribute 20% of the contribution to the greenhouse gas effect. In industrialized countries, methane typically accounts for 15% of greenhouse gas emissions.

Anthropogenic methane emissions are associated with mining, fossil fuel burning, livestock farming, rice cultivation and landfills.
The GWP of methane is 23 times greater than that of CO 2 .

Nitrous oxide

Nitrous oxide (N2O) is naturally released from the oceans and tropical forests and bacteria in soils. Sources of human influence include nitrogenous fertilizers, combustion of fossil fuels and industrial production chemicals that use nitrogen, such as wastewater treatment.

In industrialized countries, N2O is responsible for approximately 6% of greenhouse gas emissions. Like CO 2 and methane, nitrous oxide is a greenhouse gas whose molecules absorb heat that tries to evaporate into space. N 2 O has 310 times greater potential than CO 2 .

Since the beginning of the Industrial Revolution, atmospheric concentrations of nitrous oxide have increased by 16% and contribute 4 to 6% to the greenhouse effect.

Fluorinated greenhouse gases

The final group of greenhouse gases includes fluorinated constituents such as hydrofluorocarbons (HFCs), which are used as refrigerants and blowing agents; perfluorinated carbons (PFCs), which are released during aluminum production; and sulfur hexaflorides (SGF-SF 6), which are used in the electronics industry.

These are the only greenhouse gases that are not produced in nature.

Atmospheric concentrations are small, accounting for about 1.5% of the total greenhouse gas emissions of industrialized countries. However, they are extremely powerful; they have 1000-4000 times more potential than CO 2, and some have more than 22,000 times more potential.

HFCs are one of the alternatives to HCFCs in refrigeration, air conditioning and foaming. The consequences of these powerful greenhouse capabilities are therefore one factor that must be taken into account when selecting alternatives and developing elimination strategies.

Greenhouse gases

Greenhouse gases- gases with high transparency in the visible range and high absorption in the far infrared range. The presence of such gases in the atmospheres of planets leads to the greenhouse effect.

The main greenhouse gas in the atmospheres of Venus and Mars is carbon dioxide, and in the Earth's atmosphere it is water vapor.

The main greenhouse gases, in order of their estimated impact on the Earth's heat balance, are water vapor, carbon dioxide, methane and ozone

Potentially, anthropogenic halogenated hydrocarbons and nitrogen oxides may also contribute to the greenhouse effect, but due to low concentrations in the atmosphere, assessing their contribution is problematic.

water vapor

Analysis of air bubbles in ice suggests there is more methane in the Earth's atmosphere now than at any time in the last 400,000 years. Since 1750, average global atmospheric methane concentrations have increased by 150 percent, from approximately 700 to 1,745 parts per billion volume (ppbv) in 1998. Over the past decade, although methane concentrations have continued to rise, the rate of increase has slowed. In the late 1970s, the growth rate was about 20 ppbv per year. In the 1980s, growth slowed to 9-13 ppbv per year. Between 1990 and 1998 there was an increase of between 0 and 13 ppbv per year. Recent studies (Dlugokencky et al.) show a steady-state concentration of 1751 ppbv between 1999 and 2002.

Methane is removed from the atmosphere through several processes. The balance between methane emissions and removal processes ultimately determines atmospheric concentrations and the residence time of methane in the atmosphere. The dominant one is oxidation through a chemical reaction with hydroxyl radicals (OH). Methane reacts with OH in the troposphere to produce CH 3 and water. Stratospheric oxidation also plays some (minor) role in removing methane from the atmosphere. These two reactions with OH account for about 90% of methane removal from the atmosphere. In addition to the reaction with OH, two more processes are known: microbiological absorption of methane in soils and the reaction of methane with chlorine (Cl) atoms on the sea surface. The contribution of these processes is 7% and less than 2%, respectively.

Ozone

Ozone is a greenhouse gas. At the same time, ozone is essential for life because it protects the Earth from harsh ultraviolet radiation Sun.

However, scientists distinguish between stratospheric and tropospheric ozone. The first (so-called ozone layer) is a permanent and basic protection against harmful radiation. The second is considered harmful, since it can be transferred to the surface of the Earth, where it harms living beings, and, moreover, is unstable and cannot be a reliable protection. In addition, the increase in the content of tropospheric ozone contributed to the increase in the greenhouse effect of the atmosphere, which (according to the most widely accepted scientific estimates) is about 25% of the contribution of CO 2

Most tropospheric ozone is formed when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds combine chemical reactions in the presence of sunlight. Transport, industrial emissions, and some chemical solvents are the main sources of these substances in the atmosphere. Methane, whose atmospheric concentrations have increased significantly over the last century, also contributes to the formation of ozone. The lifetime of tropospheric ozone is approximately 22 days; the main mechanisms for its removal are binding in the soil, decomposition under the influence of ultraviolet rays and reactions with OH and HO 2 radicals.

Tropospheric ozone concentrations are highly variable and uneven in geographic distribution. There is a system for monitoring tropospheric ozone levels in the United States and Europe, based on satellites and ground-based observations. Since the formation of ozone requires sunlight, high levels ozone levels are usually observed during periods of hot and sunny weather. The current average concentration of tropospheric ozone in Europe is three times higher than in the pre-industrial era.

The increase in ozone concentration near the surface has a strong negative impact on vegetation, damaging leaves and inhibiting their photosynthetic potential. The historical process of increasing ground-level ozone concentrations likely suppressed the ability of land surfaces to absorb CO 2 and therefore increased the rate of CO 2 growth in the 20th century. Scientists (Sitch et al. 2007) believe that this indirect impact climate change nearly doubled the contribution that ground-level ozone concentrations made to climate change. Reducing lower tropospheric ozone pollution could offset 1–2 decades of CO 2 emissions at relatively low economic costs (Wallack and Ramanathan, 2009).

Nitric oxide

The greenhouse activity of nitrous oxide is 298 times higher than that of carbon dioxide.

Freons

The greenhouse activity of freons is 1300-8500 times higher than that of carbon dioxide. The main sources of freon are refrigeration units and aerosols.

see also

• Kyoto Protocol (CO 2 , CH 4 , HFCs, PFCs, N 2 O, SF 6)

Notes

Links

• Point Carbon is an analytics company specializing in providing independent estimates, forecasts, and information on greenhouse gas emissions trading.
• “GIS – atmosphere” automatic system for monitoring atmospheric air quality

Data scientific research provide information that without reducing the mass of greenhouse gases in earth's atmosphere Humanity cannot avoid the deterioration of the planet's climate.

Where did they come from?

Greenhouse gases, being in the atmospheres of planets, contribute to some dangerous effects. It is named accordingly – greenhouse. On the one hand, without this phenomenon our planet would never have been able to warm up enough for life to arise on it. On the other hand, everything is good in moderation and up to a certain point. Therefore, we will talk about the problems of civilization associated with the phenomenon of greenhouse gases, which, having played its positive role, changed its quality over time and became a topic for discussion, research and general concern.

Many millions of years ago, the Sun, heating the Earth, gradually turned it into a source of energy. Some of her warmth went into space. In addition, it was reflected by gases in the atmosphere and warmed the layers of air close to the ground. Scientists gave this process, similar to heat conservation under a transparent film in greenhouses, a name. And they also named the gases that provoke it simply. Their name is “greenhouse gases”.

At the dawn of the establishment of the Earth's climate, the active activity of volcanoes contributed to the emergence of this effect. Emissions in the form of water vapor and carbon dioxide remained in the atmosphere in huge quantities. The result was a hypergreenhouse effect that heated the World Ocean almost to the boiling point. And only with the advent of the green biosphere, which absorbs carbon dioxide from the atmosphere, temperature regime The planet gradually returned to normal.

However, general industrialization and the constant growth of production capacity have changed not only chemical composition greenhouse gases, but also the essence of this phenomenon.

They are known firsthand

A greenhouse gas is a compound that lingers in the Earth's atmosphere and becomes a barrier to its thermal radiation on its way to space. The heat given off by the planet comes back again. As a result, the indicators average temperature are growing steadily, which can lead to unpredictable consequences.

Excessive heating of the planet occurs due to differences in the transparency of the layers of the atmosphere. Sun rays pass through them easily. The atmosphere is transparent to ultraviolet light. Teplov infrared radiation it is difficult to break through its lower layers, where greenhouse gases accumulate. The point is that they create a seal.

The Kyoto Protocol contains a clear list of greenhouse gases, the presence of which in the Earth's atmosphere should be combated. These include:

• water vapor;
• carbon dioxide;
• methane;
• nitrous oxide;
• freons;
• ozone;
• perfluorocarbons;
• sulfur hexafluoride.

Dangerous Potential

Water vapor is classified as a natural gas, but its participation in the formation of the greenhouse effect is quite large. He shouldn't be underestimated.

Carbon dioxide is considered one of the main factors influencing the planet's climate. Its share in the atmosphere is about 64%, and its role in global warming is exactly that great. The main sources of its release into the atmosphere are:

• volcanic eruptions;
• metabolic process of the biosphere;
• burning biomass and fossil fuels;
• deforestation;
• production processes.

Methane does not decay in the atmosphere for 10 years and poses a serious threat to the Earth's climate. Its greenhouse effect is 28 times greater than that of carbon dioxide, and in the next 20 years, if its emissions are not stopped, this superiority will reach 84. Its main sources are anthropogenic in nature. This:

• agricultural production, in particular rice cultivation;
• cattle breeding (increase in livestock and, as a consequence, sewage);
• burning of forest.

Some of the greenhouse methane comes from leakage during mining. coal. It is also released when extracted natural gas.

Freons pose a particular danger to the environment. They are mainly used in aerosols and refrigeration applications.

Nitrous oxide is a greenhouse gas, which is one of the leading places in terms of quantity in the atmosphere and influence on global warming. Sources of its origin and application:

• production of mineral fertilizers in the chemical industry;
• the food industry uses it as a propellant;
• in the mechanical and rocket engineering industries it is used in engines.

Ozone, or rather the part of it that is classified as harmful gases that create the greenhouse effect, is located in the lower layers of the troposphere. Increasing near the ground, its amount can harm green spaces, damaging their leaves and reducing the ability to photosynthesize. It is mainly formed as a result of the interaction of carbon oxides, nitrogen oxides with water vapor, sunlight and volatile organic compounds in the presence of oxygen. The main sources of these substances in the atmosphere are greenhouse gas emissions from industrial facilities, vehicles and chemical solvents.

Perfluorocarbons are a result of the production of aluminum, solvents and electronics. They are used in dielectrics, heat carriers, coolants, lubricating oils and even as artificial blood. They can only be obtained by chemical synthesis. Like most fluorinated gases, they are hazardous to environment. Their greenhouse potential is estimated to be hundreds of times higher than that of carbon dioxide.

Sulfur hexafluoride is also one of those greenhouse gases that are listed as potentially hazardous in the Kyoto Protocol. It is used in the field of fire extinguishing, in the electronics and metallurgical industries as a process medium, its role as a refrigerant is known, etc. Its emissions remain in the atmosphere for a long time and actively accumulate infrared radiation.

Ways to solve the problem

The world community is making a lot of efforts to develop unified program actions to reduce greenhouse gas emissions.

One of the serious components of environmental policy is the approval of standards for emissions of fuel combustion products and the reduction of fuel use due to the transition of the auto industry to the production of electric vehicles.

Job nuclear power plants, which do not use coal and petroleum products, indirectly already makes it possible to reduce the amount of carbon dioxide in the atmosphere by several times.

Transnational gas and oil processing companies coordinate their activities with international environmental organizations and governments to combat methane emissions. They have already been joined by many large oil and gas producing states, such as Nigeria, Mexico, Norway, the USA, and Russia.

A significant reduction or ban on deforestation can also have a significant impact on improving the environment. As trees grow, they absorb enormous amounts of carbon dioxide. During cutting they release it. Reducing the percentage of arable land in tropical countries has already made a significant contribution to optimizing global greenhouse gas emissions.

New European restrictions are part of the global environmental program technological characteristics boilers and water heaters. All developments of such household appliances must henceforth comply with the requirements of controlling the carbon dioxide emissions during their use. It is expected that, subject to the introduction of new technologies, this greenhouse gas will reduce its presence in the atmosphere by 136 million tons over six years.

Renewable energy – a challenge to greenhouse gases

IN Lately appeared fashion trend invest in the development of renewable energy industries. The percentage of its use in global consumption is slowly but steadily growing. It is called “green energy” because it originates in natural regular processes that occur in nature.

Resources such as water flows, wind, sunlight, tides, man has now learned to use for technical needs. The percentage of global energy consumption from renewable sources had already reached 20 by 2014. Every year, 30% more wind energy is used worldwide. The production of photovoltaic panels is increasing. Solar power plants are growing in popularity in Spain and Germany.

Running car engines emit greenhouse gases in huge quantities. Proof of this fact has become an incentive to search for “green” types of gasoline. Recent studies have shown that bioethanol can be considered as an alternative motor fuel from petroleum products. As part of an environmental program, Brazil has been producing ethanol from sugarcane for several years. It is produced in large quantities from US grain, rice and corn pulp. Biofuel is already beginning to partially replace gasoline in many countries around the world.

Everyone's contribution

Greenhouse gases and their destructive work cannot be seen or felt. It’s still hard for us to imagine all this. However this problem may affect the next generation. By thinking beyond themselves, people can take part in solving this problem today. If each of us plants a tree, puts out a fire in the forest in time, and switches to a car powered by electricity at the first opportunity, he will definitely leave his mark in the future.

Greenhouse gases

Greenhouse gases are gases that are believed to cause the global greenhouse effect.

The main greenhouse gases, in order of their estimated impact on the Earth's thermal balance, are water vapor, carbon dioxide, methane, ozone, halocarbons and nitrous oxide.

water vapor

Water vapor is the main natural greenhouse gas, responsible for more than 60% of the effect. Direct anthropogenic impact on this source is insignificant. At the same time, an increase in the Earth's temperature caused by other factors increases evaporation and the total concentration of water vapor in the atmosphere at an almost constant relative humidity, which, in turn, increases the greenhouse effect. Thus, some positive feedback occurs.

Methane

A gigantic eruption of methane accumulated under the seabed 55 million years ago warmed the Earth by 7 degrees Celsius.

The same thing can happen now - this assumption was confirmed by researchers from NASA. Using computer simulations ancient climate, they tried to better understand the role of methane in changing it. Currently, most research on the greenhouse effect focuses on the role of carbon dioxide in this effect, although the potential of methane to retain heat in the atmosphere is 20 times greater than that of carbon dioxide.

A variety of gas-powered household appliances are contributing to the increase in methane content in the atmosphere.

Over the past 200 years, methane in the atmosphere has more than doubled due to decomposition of organic matter in swamps and wet lowlands, as well as leaks from man-made objects such as gas pipelines, coal mines, increased irrigation and off-gassing from livestock. But there is another source of methane - decaying organic matter in ocean sediments, preserved frozen under the seabed.

Usually low temperatures And high pressure keep methane under the ocean in a stable state, but this was not always the case. During periods of global warming, such as the late Paleocene Thermal Maximum, which occurred 55 million years ago and lasted for 100 thousand years, the movement of lithospheric plates, particularly in the Indian subcontinent, led to a drop in pressure on the seafloor and could cause a large release of methane. As the atmosphere and ocean began to warm, methane emissions could increase. Some scientists believe that current global warming could lead to the development of events according to the same scenario - if the ocean warms up significantly.

When methane enters the atmosphere, it reacts with oxygen and hydrogen molecules to create carbon dioxide and water vapor, each of which can cause the greenhouse effect. According to previous forecasts, all emitted methane will turn into carbon dioxide and water in about 10 years. If this is true, then increasing carbon dioxide concentrations will be the main cause of warming of the planet. However, attempts to confirm the reasoning with references to the past were unsuccessful - no traces of an increase in carbon dioxide concentration 55 million years ago were found.

The models used in the new study showed that when the level of methane in the atmosphere sharply increases, the content of oxygen and hydrogen reacting with methane in it decreases (until the reaction stops), and the remaining methane remains in the air for hundreds of years, itself becoming a cause of global warming. And these hundreds of years are enough to warm up the atmosphere, melt the ice in the oceans and change the entire climate system.

The main anthropogenic sources of methane are digestive fermentation in livestock, rice growing, and biomass burning (including deforestation). As recent studies have shown, fast growth concentrations of methane in the atmosphere occurred in the first millennium AD (presumably as a result of the expansion of agricultural production and livestock breeding and the burning of forests). Between 1000 and 1700, methane concentrations fell by 40%, but began to rise again in recent centuries (presumably as a result of the expansion of arable land and pastures and the burning of forests, the use of wood for heating, increased numbers of livestock, sewage, and rice cultivation) . Some contribution to the supply of methane comes from leaks during the development of coal and natural gas deposits, as well as the emission of methane as part of biogas generated at waste disposal sites

Carbon dioxide

Sources of carbon dioxide in the Earth's atmosphere are volcanic emissions, vital activity of organisms, and human activity. Anthropogenic sources include the combustion of fossil fuels, the burning of biomass (including deforestation), and some industrial processes (for example, cement production). The main consumers of carbon dioxide are plants. Normally, the biocenosis absorbs approximately the same amount of carbon dioxide as it produces (including through biomass decay).

The influence of carbon dioxide on the intensity of the greenhouse effect.

Much still needs to be learned about the carbon cycle and the role of the world's oceans as a vast reservoir of carbon dioxide. As mentioned above, every year humanity adds 7 billion tons of carbon in the form of CO 2 to the existing 750 billion tons. But only about half of our emissions - 3 billion tons - remain in the air. This can be explained by the fact that most of the CO 2 is used by terrestrial and sea ​​plants, buried in marine sedimentary rocks, absorbed sea ​​water or otherwise absorbed. Of this large portion of CO 2 (about 4 billion tons), the ocean absorbs about two billion tons of atmospheric carbon dioxide each year.

All this increases the number of unanswered questions: How exactly? sea ​​water interacts with atmospheric air, absorbing CO 2? How much more carbon can the seas absorb, and what level of global warming might affect their capacity? What is the capacity of the oceans to absorb and store heat trapped by climate change?

The role of clouds and suspended particles in air currents called aerosols is not easy to take into account when building a climate model. Clouds shade the earth's surface, leading to cooling, but depending on their height, density and other conditions, they can also trap heat reflected from the earth's surface, increasing the intensity of the greenhouse effect. The effect of aerosols is also interesting. Some of them alter water vapor, condensing it into small droplets that form clouds. These clouds are very dense and obscure the Earth's surface for weeks. That is, they block sunlight until they fall with precipitation.

The combined effect can be enormous: the 1991 eruption of Mount Pinatuba in the Philippines released a colossal volume of sulfates into the stratosphere, causing a worldwide drop in temperature that lasted two years.

Thus, our own pollution, mainly caused by burning sulfur-containing coal and oils, may temporarily offset the effects of global warming. Experts estimate that aerosols reduced the amount of warming by 20% during the 20th century. In general, temperatures have been rising since the 1940s, but have fallen since 1970. The aerosol effect may help explain the anomalous cooling in the middle of the last century.

In 2006, carbon dioxide emissions into the atmosphere amounted to 24 billion tons. A very active group of researchers argues against the idea that human activity is one of the causes of global warming. In her opinion, the main thing lies in the natural processes of climate change and increased solar activity. But according to Klaus Hasselmann, head of the German Climatological Center in Hamburg, only 5% can be explained natural reasons, and the remaining 95% is a technogenic factor caused by human activity.

Some scientists also do not connect the increase in CO 2 with an increase in temperature. Skeptics say that if rising temperatures are to be blamed on rising CO 2 emissions, temperatures must have risen during the post-war economic boom, when fossil fuels were burned in huge quantities. However, Jerry Mallman, director of the Geophysical Fluid Dynamics Laboratory, calculated that increased use of coal and oils rapidly increased the sulfur content in the atmosphere, causing cooling. After 1970, the thermal effect of long life cycle CO 2 and methane suppressed rapidly decaying aerosols, causing temperatures to rise. Thus, we can conclude that the influence of carbon dioxide on the intensity of the greenhouse effect is enormous and undeniable.

However, the increasing greenhouse effect may not be catastrophic. Indeed, high temperatures may be welcomed where they are quite rare. Since 1900, the greatest warming has been from 40 to 70 0 northern latitude, including Russia, Europe, and the northern part of the United States, where industrial emissions of greenhouse gases began first. Most of the warming occurs at night, primarily due to increased cloud cover, which traps outgoing heat. As a result, the sowing season was extended by a week.

Moreover, the greenhouse effect may be good news for some farmers. High concentrations of CO 2 can have a positive effect on plants because plants use carbon dioxide during photosynthesis, converting it into living tissue. Therefore, more plants mean more absorption of CO 2 from the atmosphere, slowing down global warming.

This phenomenon was studied by American specialists. They decided to create a model of the world with double the amount of CO 2 in the air. For this they used a fourteen-year-old Pine forest in Northern California. Gas was pumped through pipes installed among the trees. Photosynthesis increased by 50-60%. But the effect soon became the opposite. The suffocating trees could not cope with such volumes of carbon dioxide. The advantage in the process of photosynthesis was lost. This is another example of how human manipulation leads to unexpected results.

But these small positive aspects of the greenhouse effect cannot be compared with the negative ones. Take at least the experience with pine forest, where the volume of CO 2 has been doubled, and by the end of this century the concentration of CO 2 is predicted to quadruple. One can imagine how catastrophic the consequences could be for plants. And this, in turn, will increase the volume of CO 2, since the fewer plants, the greater the concentration of CO 2.

Consequences of the greenhouse effect

greenhouse effect gases climate

As temperatures rise, the evaporation of water from oceans, lakes, rivers, etc. will increase. Since heated air can contain more water vapor, this creates a powerful effect feedback: The warmer it gets, the higher the water vapor content in the air, and this, in turn, increases the greenhouse effect.

Human activity has little effect on the amount of water vapor in the atmosphere. But we emit other greenhouse gases, which makes the greenhouse effect more and more intense. Scientists believe that increasing CO 2 emissions, mostly from burning fossil fuels, explain at least about 60% of the Earth's warming since 1850. The concentration of carbon dioxide in the atmosphere is increasing by about 0.3% per year, and is now about 30% higher than before the industrial revolution. If we express this in absolute terms, then every year humanity adds approximately 7 billion tons. Despite the fact that this is a small part in relation to the total amount of carbon dioxide in the atmosphere - 750 billion tons, and even smaller compared to the amount of CO 2 contained in the World Ocean - approximately 35 trillion tons, it remains very significant. Reason: natural processes are in equilibrium, such a volume of CO 2 enters the atmosphere, which is removed from there. A human activity only adds CO 2.