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77-566: Black smoke or Black Smoke may refer to: Soot , which appears as black smoke Black smoke (The War of the Worlds) , a fictional alien weapon Black Smoke (song) , a 2015 German Eurovision entry Black Smoke Rising , an album by Greta Van Fleet Black Smoke Band, the creators of Jeff Wayne's Musical Version of The War of the Worlds Black Smoke Shen Long ,

154-605: A Dragon Ball character Black Smoke Monster , a monster from Lost Black smokers and white smokers Fumata showing a pope has not been elected Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Black Smoke . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Black_Smoke&oldid=1251228992 " Category : Disambiguation pages Hidden categories: Short description

231-542: A "known human carcinogen " by the International Agency for Research on Cancer (IARC). Soot forms during incomplete combustion from precursor molecules such as acetylene. It consists of agglomerated nanoparticles with diameters between 6 and 30  nm . The soot particles can be mixed with metal oxides and with minerals and can be coated with sulfuric acid . Many details of soot formation chemistry remain unanswered and controversial, but there have been

308-600: A 'tipping point' than the 0 °C boundary that separates frozen from liquid water—the bright, reflective snow and ice from the dark, heat-absorbing ocean." Black carbon emissions from northern Eurasia, North America, and Asia have the greatest absolute impact on Arctic warming. However, black carbon emissions actually occurring within the Arctic have a disproportionately larger impact per particle on Arctic warming than emissions originating elsewhere. As Arctic ice melts and shipping activity increases, emissions originating within

385-448: A better nutrient retention capacity than surrounding infertile soils. In this context, the slash and burn agricultural practice used in tropical regions does not only enhance productivity by releasing nutrients from the burned vegetation but also by adding black carbon to the soil. Nonetheless, for sustainable management, a slash-and-char practice would be better to prevent high emissions of CO 2 and volatile black carbon. Furthermore,

462-673: A combination of transmittance and reflectance is measured. Aethalometers are frequently used devices that optically detect the changing absorption of light transmitted through a filter ticket. The USEPA Environmental Technology Verification program evaluated both the aethalometer and also the Sunset Laboratory thermal-optical analyzer. A multiangle absorption photometer takes into account both transmitted and reflected light. Alternative methods rely on satellite based measurements of optical depth for large areas or more recently on spectral noise analysis for very local concentrations. In

539-488: A direct effect on the lung function of adults and an inflammatory effect on the respiratory system of children. A recent study found no effect of black carbon on blood pressure when combined with physical activity . The public health benefits of reduction in the amount of soot and other particulate matter has been recognized for years. However, high concentrations persist in industrializing areas in Asia and in urban areas in

616-433: A drastic reduction of fossil fuel related BC" throughout the world. Given black carbon's relatively short lifespan, reducing black carbon emissions would reduce warming within weeks. Because black carbon remains in the atmosphere only for a few weeks, reducing black carbon emissions may be the fastest means of slowing climate change in the near term. Control of black carbon, particularly from fossil-fuel and biofuel sources,

693-737: A few agreements: Soot, particularly diesel exhaust pollution, accounts for over one-quarter of the total hazardous pollution in the air. Among these diesel emission components, particulate matter has been a serious concern for human health due to its direct and broad impact on the respiratory organs. In earlier times, health professionals associated PM 10 (diameter < 10  μm ) with chronic lung disease, lung cancer , influenza , asthma , and increased mortality rate . However, recent scientific studies suggest that these correlations be more closely linked with fine particles (PM 2.5 ) and ultra-fine particles (PM 0.1 ). Long-term exposure to urban air pollution containing soot increases

770-506: A given set of operating conditions. However, empirical models cannot be used to investigate the underlying mechanisms of soot production. Therefore, these models are not flexible enough to handle changes in operating conditions. They are only useful for testing previously established designed experiments under specific conditions. Second, semi-empirical models solve rate equations that are calibrated using experimental data. Semi-empirical models reduce computational costs primarily by simplifying

847-498: A glacier saddle of Mt. Everest (Qomolangma) in 2003 showed industrially induced sulfate from South Asia may cross over the highly elevated Himalaya. This indicated BC in South Asia could also have the same transport mode. And such kind of signal might have been detected in at a black carbon monitoring site in the hinterland of Tibet. Snow sampling and measurement suggested black carbon deposited in some Himalayan glaciers may reduce

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924-448: A global scale then one would expect a heating effect over surfaces with a high surface albedo like snow or ice. Furthermore, if these particles are deposited in the snow an additional heating effect would occur due to reductions in the surface albedo. Levels of black carbon are most often determined based on the modification of the optical properties of a fiber filter by deposited particles. Either filter transmittance, filter reflectance or

1001-441: A high level of detailed chemical and physical processes. Finally, comprehensive models (detailed models) are usually expensive and slow to compute, as they are much more complex than empirical or semi-empirical models. Thanks to recent technological progress in computation, it has become more feasible to use detailed theoretical models and obtain more realistic results; however, further advancement of comprehensive theoretical models

1078-930: A large deposit collects in one, it can ignite and create a chimney fire . Regular cleaning by a chimney sweep should eliminate the problem. Soot mechanism is difficult to model mathematically because of the large number of primary components of diesel fuel , complex combustion mechanisms, and the heterogeneous interactions during soot formation. Soot models are broadly categorized into three subgroups: empirical (equations that are adjusted to match experimental soot profiles), semi-empirical (combined mathematical equations and some empirical models which used for particle number density and soot volume and mass fraction), and detailed theoretical mechanisms (covers detailed chemical kinetics and physical models in all phases). First, empirical models use correlations of experimental data to predict trends in soot production. Empirical models are easy to implement and provide excellent correlations for

1155-449: A large forcing because of a positive feedback: Reduced snow albedo would increase surface temperature. The increased surface temperature would decrease the snow cover and further decrease surface albedo. Indirect effect Black carbon may also indirectly cause changes in the absorption or reflection of solar radiation through changes in the properties and behavior of clouds. Research scheduled for publication in 2013 shows black carbon plays

1232-822: A light beam or derived from noise measurements. The disastrous effects of coal pollution on human health and mortality in the early 1950s in London led to the UK Clean Air Act 1956 . This act led to dramatic reductions of soot concentrations in the United Kingdom which were followed by similar reductions in US cities like Pittsburgh and St. Louis. These reductions were largely achieved by the decreased use of soft coal for domestic heating by switching either to "smokeless" coals or other forms of fuel, such as fuel oil and natural gas. The steady reduction of smoke pollution in

1309-568: A more direct pathway involving ring condensation or polymerization reactions building on the existing aromatic structure. The Intergovernmental Panel on Climate Change (IPCC) adopted the description of soot particles given in the glossary of Charlson and Heintzenberg (1995), "Particles formed during the quenching of gases at the outer edge of flames of organic vapours, consisting predominantly of carbon, with lesser amounts of oxygen and hydrogen present as carboxyl and phenolic groups and exhibiting an imperfect graphitic structure". Formation of soot

1386-534: A research study published in June 2022, atmospheric scientist Christopher Maloney and his colleagues noted that rocket launches release tiny particles called aerosols in the stratosphere and increase ozone layer loss. They used a climate model to determine the impact of the black carbon coming out of the rocket's engine nozzle. Using various scenarios of growing number of rocket launches, they found that each year, rocket launches could expel 1–10 gigagrams of black carbon at

1463-423: A result of this feedback process, "BC on snow warms the planet about three times more than an equal forcing of CO 2 ." When black carbon concentrations in the Arctic increase during the winter and spring due to Arctic Haze , surface temperatures increase by 0.5 °C. Black carbon emissions also significantly contribute to Arctic ice-melt, which is critical because "nothing in climate is more aptly described as

1540-428: A role second only to carbon dioxide in climate change. Effects are complex, resulting from a variety of factors, but due to the short life of black carbon in the atmosphere, about a week as compared to carbon dioxide which last centuries, control of black carbon offers possible opportunities for slowing, or even reversing, climate warming. Estimates of black carbon's globally averaged direct radiative forcing vary from

1617-415: A significant opportunity to reduce black carbon's global warming impact. Biomass burning emits greater amounts of climate-cooling aerosols and particulate matter than black carbon, resulting in short-term cooling. However, over the long-term, biomass burning may cause a net warming when CO 2 emissions and deforestation are considered. Reducing biomass emissions would therefore reduce global warming in

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1694-633: A significant positive radiative forcing". The IPCC also notes that emissions from biomass burning, which usually have a negative forcing, have a positive forcing over snow fields in areas such as the Himalayas. A 2013 study quantified that gas flares contributed over 40% of the black carbon deposited in the Arctic. According to Charles Zender, black carbon is a significant contributor to Arctic ice-melt, and reducing such emissions may be "the most efficient way to mitigate Arctic warming that we know of". The "climate forcing due to snow/ice albedo change

1771-528: A type of matter where the chunks tend to be too large to have an aerosol form as is the case with soot. Soot as an airborne contaminant in the environment has many different sources, all of which are results of some form of pyrolysis . They include soot from coal burning, internal-combustion engines, power-plant boilers, hog-fuel boilers, ship boilers, central steam-heat boilers, waste incineration , local field burning, house fires, forest fires, fireplaces, and furnaces. These exterior sources also contribute to

1848-605: Is "as much as 55% of the CO 2 forcing and is larger than the forcing due to the other greenhouse gasses (GHGs) such as CH 4 , CFCs, N 2 O, or tropospheric ozone." Table 1: Estimates of Black Carbon Radiative Forcing, by Effect 0.8 ± 0.4 (2001) 1.0 ± 0.5 (2002) »0.7 ± 0.2 (2003) 0.8 (2005) 1.0 arctic Table 2: Estimated Climate Forcings (W/m ) According to the IPCC , "the presence of black carbon over highly reflective surfaces, such as snow and ice, or clouds, may cause

1925-651: Is a climate forcing agent contributing to global warming . Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice (direct effects) and indirectly by interaction with clouds, with the total forcing of 1.1 W/m . Black carbon stays in the atmosphere for only several days to weeks. In contrast, potent greenhouse gases have longer lifecycles. For example, carbon dioxide (CO 2 ) has an atmospheric lifetime of more than 100 years. The IPCC and other climate researchers have posited that reducing black carbon

2002-422: Is a complex process, an evolution of matter in which a number of molecules undergo many chemical and physical reactions within a few milliseconds. Soot always contains nanoparticles of graphite and diamond, a phenomenon known as gemmy soot. Soot is a powder-like form of amorphous carbon . Gas-phase soot contains polycyclic aromatic hydrocarbons (PAHs). The PAHs in soot are known mutagens and are classified as

2079-548: Is defined purely as carbonaceous particles, but in others it is defined to include the whole ensemble of particles resulting from partial combustion of organic matter or fossil fuels - as such it can include non carbon elements like sulphur and even traces of metal. In many definitions, soot is assumed to be black, but in some definitions it can be composed partly or even mainly of brown carbon , and so can also be medium or even light gray in colour. Terms like "soot", "carbon black", and "black carbon" are often used to mean

2156-451: Is different from Wikidata All article disambiguation pages All disambiguation pages Soot Soot causes various types of cancer and lung disease. Among scientists, exact definitions for soot vary, depending partly on their field. For example, atmospheric scientists may use a different definition compared to toxicologists . Soot's definition can also vary across time, and from paper to paper even among scientists in

2233-487: Is emitted from burning biofuels, 40% from fossil fuels , and 40% from open biomass burning. Similar estimates of the sources of black carbon emissions are as follows: Black carbon sources vary by region. For example, the majority of soot emissions in South Asia are due to biomass cooking, whereas in East Asia, coal combustion for residential and industrial uses plays a larger role. In Western Europe, traffic seems to be

2310-518: Is inhaled in traffic and at other locations as at the home address. Despite the fact that a large portion of the exposure occurs as short peaks of high concentrations, it is unclear how to define peaks and determine their frequency and health impact. High peak concentrations are encountered during car driving. High in-vehicle concentrations of black carbon have been associated with driving during rush hours, on highways and in dense traffic. Even relatively low exposure concentrations of black carbon have

2387-410: Is limited by the accuracy of modeling of formation mechanisms. Additionally, phenomenological models have found wide use recently. Phenomenological soot models, which may be categorized as semi-empirical models, correlate empirically observed phenomena in a way that is consistent with the fundamental theory, but is not directly derived from the theory. These models use sub-models developed to describe

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2464-594: Is of the order of 1.0 W/m at middle- and high-latitude land areas in the Northern Hemisphere and over the Arctic Ocean." The "soot effect on snow albedo may be responsible for a quarter of observed global warming". "Soot deposition increases surface melt on ice masses, and the meltwater spurs multiple radiative and dynamical feedback processes that accelerate ice disintegration," according to NASA scientists James Hansen and Larissa Nazarenko. As

2541-538: Is one of the easiest ways to slow down short term global warming. The term black carbon is also used in soil science and geology , referring to deposited atmospheric black carbon or directly incorporated black carbon from vegetation fires. Especially in the tropics, black carbon in soils significantly contributes to fertility as it can absorb important plant nutrients. In climatology, biochar carbon removal sequesters atmospheric carbon as black carbon to slow global warming. Michael Faraday recognized that soot

2618-448: Is sometimes used synonymously with soot, but is now used preferentially in atmospheric science, though some prefer more precise terms like 'light-absorbing carbon'. Unlike carbon black, black carbon is produced unintentionally. The chemical composition of black carbon is much more varied, and typically has a much lower proportion of elemental carbon, compared with carbon black . In some definitions, black carbon also includes charcoal ,

2695-432: Is therefore particularly harmful. It is estimated that from 640,000 to 4,900,000 premature human deaths could be prevented every year by using available mitigation measures to reduce black carbon in the atmosphere. Humans are exposed to black carbon by inhalation of air in the immediate vicinity of local sources. Important indoor sources include candles and biomass burning whereas traffic and occasionally forest fires are

2772-500: The IPCC 's estimate of + 0.34 watts per square meter (W/m ) ± 0.25, to a more recent estimate by V. Ramanathan and G. Carmichael of 0.9 W/m . The IPCC also estimated the globally averaged snow albedo effect of black carbon at +0.1 ± 0.1 W/m . Based on the IPCC estimate, it would be reasonable to conclude that the combined direct and indirect snow albedo effects for black carbon rank it as

2849-699: The NOAA AGASP program, the first measurements of such distributions in the Arctic atmosphere were obtained with an aethalometer which had the capability of measuring black carbon on a real-time basis. These measurements showed substantial concentrations of black carbon found throughout the western Arctic troposphere including the North Pole. The vertical profiles showed either a strongly layered structure or an almost uniform distribution up to eight kilometers with concentrations within layers as large as those found at ground level in typical mid-latitude urban areas in

2926-614: The total organic carbon stored in soils is contributed by black carbon. Especially for tropical soils black carbon serves as a reservoir for nutrients. Experiments showed that soils without high amounts of black carbon are significantly less fertile than soils that contain black carbon. An example of this increased soil fertility is the Terra preta soils of central Amazonia, presumably human-made by pre-Columbian native populations. Terra preta soils have, on average, three times higher soil organic matter (SOM) content, higher nutrient levels, and

3003-484: The 20th century. Black carbon Black carbon ( BC ) is the light-absorbing refractory form of elemental carbon remaining after pyrolysis (e.g., charcoal ) or produced by incomplete combustion (e.g., soot ). Tihomir Novakov originated the term black carbon in the 1970s, after identifying black carbon as fine particulate matter (PM ≤ 2.5  μm aerodynamic diameter ) in aerosols. Aerosol black carbon occurs in several linked forms. Formed through

3080-567: The Arctic are expected to rise. In some regions, such as the Himalayas, the impact of black carbon on melting snowpack and glaciers may be equal to that of CO 2 . Warmer air resulting from the presence of black carbon in South and East Asia over the Himalayas contributes to a warming of approximately 0.6 °C. An "analysis of temperature trends on the Tibetan side of the Himalayas reveals warming in excess of 1 °C." A summer aerosol sampling on

3157-442: The IPCC's report estimate that emissions from black carbon are the second-largest contributor to global warming after carbon dioxide emissions, and that reducing these emissions may be the fastest strategy for slowing climate change. Since 1950, many countries have significantly reduced black carbon emissions, especially from fossil fuel sources, primarily to improve public health from improved air quality, and "technology exists for

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3234-478: The United States and Europe which led to improved controls of these emissions. In the less-developed regions of the world where there were limited or no controls on soot emissions the air quality continued to degrade as the population increased. It was not generally realized until many years later that from the perspective of global effects the emissions from these regions were extremely important. Most of

3311-488: The United States. The absorption optical depths associated with these vertical profiles were large as evidenced by a vertical profile over the Norwegian arctic where absorption optical depths of 0.023 to 0.052 were calculated respectively for external and internal mixtures of black carbon with the other aerosol components. Optical depths of these magnitudes lead to a substantial change in the solar radiation balance over

3388-528: The West such as Chicago . The WHO estimates that air pollution causes nearly two million premature deaths per year. By reducing black carbon, a primary component of fine particulate matter, the health risks from air pollution will decline. In fact, public health concerns have given rise to leading to many efforts to reduce such emissions, for example, from diesel vehicles and cooking stoves. Direct effect Black carbon particles directly absorb sunlight and reduce

3465-405: The accuracy of the model parameters is low. Unlike empirical models, phenomenological models are flexible enough to produce reasonable results when multiple operating conditions change. Historically soot was used in manufacturing artistic paints and shoe polish , as well as a blackener for Russia leather for boots. With the advent of the printing press it was used in the printing ink well into

3542-1083: The adoption of pending International Maritime Organization (IMO) regulations. Existing regulations also could be expanded to increase the use of clean diesel and clean coal technologies and to develop second-generation technologies. Today, the majority of black carbon emissions are from developing countries and this trend is expected to increase. The largest sources of black carbon are Asia, Latin America, and Africa. China and India together account for 25–35% of global black carbon emissions. Black carbon emissions from China doubled from 2000 to 2006. Existing and well-tested technologies used by developed countries, such as clean diesel and clean coal, could be transferred to developing countries to reduce their emissions. Black carbon emissions are highest in and around major source regions. This results in regional hotspots of atmospheric solar heating due to black carbon. Hotspot areas include: Approximately three billion people live in these hotspots. Approximately 20% of black carbon

3619-535: The air causes premature human mortality and disability. In addition, atmospheric black carbon changes the radiative energy balance of the climate system in a way that raises air and surface temperatures, causing a variety of detrimental environmental impacts on humans, on agriculture, and on plant and animal ecosystems. Particulate matter is the most harmful to public health of all air pollutants in Europe. Black carbon particulate matter contains very fine carcinogens and

3696-427: The altitudes over 5500 m above sea level. In its 2007 report, the IPCC estimated for the first time the direct radiative forcing of black carbon from fossil fuel emissions at + 0.2 W/m , and the radiative forcing of black carbon through its effect on the surface albedo of snow and ice at an additional + 0.1 W/m . More recent studies and public testimony by many of the same scientists cited in

3773-413: The chemistry in soot formation and oxidation. Semi-empirical models reduce the size of chemical mechanisms and use simpler molecules, such as acetylene as precursors. Detailed theoretical models use extensive chemical mechanisms containing hundreds of chemical reactions in order to predict concentrations of soot. Detailed theoretical soot models contain all the components present in the soot formation with

3850-415: The contemporary atmospheric research community. Soot is composed of a complex mixture of organic compounds which are weakly absorbing in the visible spectral region and a highly absorbing black component which is variously called "elemental", "graphitic" or "black carbon". The term elemental carbon has been used in conjunction with thermal and wet chemical determinations and the term graphitic carbon suggests

3927-480: The developments mentioned above relate to air quality in urban atmospheres. The first indications of the role of black carbon in a larger, global context came from studies of the Arctic Haze phenomena. Black carbon was identified in the Arctic haze aerosols and in the Arctic snow. In general, aerosol particles can affect the radiation balance leading to a cooling or heating effect with the magnitude and sign of

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4004-437: The different processes (or phenomena) observed during the combustion process. Examples of sub-models of phenomenological empirical models include spray model, lift-off model, heat release model, ignition delay model, etc. These sub-models can be empirically developed from observation or by using basic physical and chemical relations. Phenomenological models are accurate for their relative simplicity. They are useful, especially when

4081-458: The discoloration of walls and ceilings or walls and flooring where they meet. It is generally responsible for the discoloration of the walls above baseboard electric heating units. The formation and properties of soot depend strongly on the fuel composition, but may also be influenced by flame temperature. Regarding fuel composition, the rank ordering of sooting tendency of fuel components is: naphthalenes → benzenes → aliphatics . However,

4158-710: The highly reflecting Arctic snow surface during the March–April time frame of these measurements modeled the Arctic aerosol for an absorption optical depth of 0.021 (which is close to the average of an internal and external mixtures for the AGASP flights), under cloud-free conditions. These heating effects were viewed at the time as potentially one of the major causes of Arctic warming trends as described in Archives of Dept. of Energy, Basic Energy Sciences Accomplishments. Typically, black carbon accounts for 1 to 6%, and up to 60% of

4235-441: The incomplete combustion of fossil fuels , biofuel , and biomass , black carbon is one of the main types of soot particle in both anthropogenic and naturally occurring soot . As soot, black carbon causes disease and premature death. Because of these human health impacts, many countries have worked to reduce their emissions, making it an easy pollutant to abate in anthropogenic sources. In climatology , aerosol black carbon

4312-403: The indoor environment sources such as smoking of plant matter, cooking, oil lamps , candles , quartz/halogen bulbs with settled dust, fireplaces , exhaust emissions from vehicles, and defective furnaces. Soot in very low concentrations is capable of darkening surfaces or making particle agglomerates, such as those from ventilation systems, appear black . Soot is the primary cause of "ghosting",

4389-440: The industrial cities of Europe and United States caused a shift in research emphasis away from soot emissions and the almost complete neglect of black carbon as a significant aerosol constituent, at least in the United States. In the 1970s, however, a series of studies substantially changed this picture and demonstrated that black carbon as well as the organic soot components continued to be a large component in urban aerosols across

4466-422: The late 1970s and early 1980s surprisingly large ground level concentrations of black carbon were observed throughout the western Arctic. Modeling studies indicated that they could lead to heating over polar ice. One of the major uncertainties in modeling the effects of the Arctic haze on the solar radiation balance was limited knowledge of the vertical distributions of black carbon. During 1983 and 1984 as part of

4543-480: The long-term and provide co-benefits of reduced air pollution, CO 2 emissions, and deforestation. It has been estimated that by switching to slash-and-char from slash-and-burn agriculture, which turns biomass into ash using open fires that release black carbon and GHGs, 12% of anthropogenic carbon emissions caused by land use change could be reduced annually, which is approximately 0.66 Gt CO 2 -eq. per year, or 2% of all annual global CO 2 -eq emissions. In

4620-433: The lower end to 30–100 gigagrams at the extreme end in next few decades. In another study published in June 2022, researchers used a 3D model to study the impact of rocket launches and reentry. They determined that the black carbon particles emitted by the rockets results in an enhanced warming effect of almost 500 times more than other sources. Black carbon is a form of ultrafine particulate matter , which when released in

4697-471: The major outdoor sources of black carbon exposure. Concentrations of black carbon decrease sharply with increasing distance from (traffic) sources which makes it an atypical component of particulate matter . This makes it difficult to estimate exposure of populations. For particulate matter, epidemiological studies have traditionally relied on single fixed site measurements or inferred residential concentrations. Recent studies have shown that as much black carbon

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4774-423: The mid-Himalaya glaciers revealed by MODIS data since 2000 could be partially attributed to black carbon and light absorbing impurities like dust in the springtime, which was later extended to the whole Hindu Kush-Kararoram-Himalaya glaciers research finding a widespread darkening trend of -0.001 yr over the period of 2000–2011. The most rapid decrease in albedo (more negative than -0.0015 yr ) occurred in

4851-572: The most important source since high concentrations coincide with proximity to major roads or participation to (motorized) traffic. Fossil fuel and biomass soot have significantly greater amounts of black carbon than climate-cooling aerosols and particulate matter, making reductions of these sources particularly powerful mitigation strategies. For example, emissions from the diesel engines and marine vessels contain higher levels of black carbon compared to other sources. Regulating black carbon emissions from diesel engines and marine vessels therefore presents

4928-420: The order of sooting tendencies of the aliphatics ( alkanes , alkenes , and alkynes ) varies dramatically depending on the flame type. The difference between the sooting tendencies of aliphatics and aromatics is thought to result mainly from the different routes of formation. Aliphatics appear to first form acetylene and polyacetylenes, which is a slow process; aromatics can form soot both by this route and also by

5005-517: The planetary albedo when suspended in the atmosphere. Semi-direct effect Black carbon absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. They may either increase or decrease cloud cover under different conditions. Snow/ice albedo effect When deposited on high albedo surfaces like ice and snow, black carbon particles reduce the total surface albedo available to reflect solar energy back into space. Small initial snow albedo reduction may have

5082-425: The positive effects of this type of agriculture are counteracted if used for large patches so that the vegetation does not prevent soil erosion. Soluble and colloidal black carbon retained on the landscape from wildfires can make its way to groundwater. On a global scale, the flow of black carbon into fresh and salt water bodies approximates the rate of wildfire black carbon production. Developed countries were once

5159-434: The presence of graphite -like micro-crystalline structures in soot as evidenced by Raman spectroscopy . The term black carbon is used to imply that this soot component is primarily responsible for the absorption of visible light. The term black carbon is sometimes used as a synonym for both the elemental and graphitic component of soot. It can be measured using different types of devices based on absorption or dispersion of

5236-466: The primary source of black carbon emissions, but this began to change in the 1950s with the adoption of pollution control technologies in those countries. Whereas the United States emits about 21% of the world's CO 2 , it emits 6.1% of the world's soot. The European Union and United States might further reduce their black carbon emissions by accelerating implementation of black carbon regulations that currently take effect in 2015 or 2020 and by supporting

5313-443: The reflectivity of the underlying surface is sufficiently high. Early studies of the effects of aerosols on atmospheric radiative transfer on a global scale assumed a dominantly scattering aerosol with only a small absorbing component, since this appears to be a good representation of naturally occurring aerosols. However, as discussed above, urban aerosols have a large black carbon component and if these particles can be transported on

5390-588: The risk of coronary artery disease . Diesel exhaust (DE) gas is a major contributor to combustion -derived particulate-matter air pollution. In human experimental studies using an exposure chamber setup, DE has been linked to acute vascular dysfunction and increased thrombus formation. This serves as a plausible mechanistic link between the previously described association between particulate matter air pollution and increased cardiovascular morbidity and mortality. Soot also tends to form in chimneys in domestic houses possessing one or more fireplaces . If

5467-484: The same field. A common feature of the definitions is that soot is composed largely of carbon based particles resulting from the incomplete burning of hydrocarbons or organic fuel such as wood. Some note that soot may be formed by other high temperature processes, not just by burning. Soot typically takes an aerosol form when first created. It tends to eventually settle onto surfaces, though some parts of it may be decomposed while still airborne. In some definitions, soot

5544-422: The same thing, even in the scientific literature, but other scientists have stated this is incorrect and that they refer to chemically and physically distinct things. Carbon black is a term for the industrial production of powdery carbonaceous matter which has been underway since the 19th century. Carbon black is composed almost entirely of elemental carbon. Carbon black is not found in regular soot - only in

5621-406: The special soot that is intentionally produced for its manufacture, mostly from specialised oil furnaces. Black carbon is a term that arose in the late twentieth century among atmospheric scientists, to describe strongly light absorbing carbonaceous particles which have a significant climate forcing affect - second only to CO 2 itself as a contributor to short term global warming. The term

5698-648: The surface albedo by 0.01–0.02. Black carbon record based on a shallow ice core drilled from the East Rongbuk glacier showed a dramatic increasing trend of black carbon concentrations in the ice stratigraphy since the 1990s, and simulated average radiative forcing caused by black carbon was nearly 2 W/m in 2002. This large warming trend is the proposed causal factor for the accelerating retreat of Himalayan glaciers, which threatens fresh water supplies and food security in China and India. A general darkening trend in

5775-403: The temperature change largely dependent on aerosol optical properties, aerosol concentrations, and the albedo of the underlying surface. A purely scattering aerosol will reflect energy that would normally be absorbed by the earth-atmosphere system back to space and leads to a cooling effect. As one adds an absorbing component to the aerosol, it can lead to a heating of the earth-atmosphere system if

5852-400: The third largest contributor to globally averaged positive radiative forcing since the pre-industrial period. In comparison, the more recent direct radiative forcing estimate by Ramanathan and Carmichael would lead one to conclude that black carbon has contributed the second largest globally averaged radiative forcing after carbon dioxide (CO 2 ), and that the radiative forcing of black carbon

5929-404: Was composed of carbon and that it was produced by the incomplete combustion of carbon-containing fuels. The term black carbon was coined by Serbian physicist Tihomir Novakov , referred to as "the godfather of black carbon studies" by James Hansen , in the 1970s. Smoke or soot was the first pollutant to be recognized as having significant environmental impact yet one of the last to be studied by

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