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117-577: Nuclear winter is a severe and prolonged global climatic cooling effect that is hypothesized to occur after widespread firestorms following a large-scale nuclear war . The hypothesis is based on the fact that such fires can inject soot into the stratosphere , where it can block some direct sunlight from reaching the surface of the Earth. It is speculated that the resulting cooling would lead to widespread crop failure and famine . When developing computer models of nuclear-winter scenarios, researchers use

234-439: A different mixture of aerosols , in this case stratospheric sulfur aerosols and volcanic ash from megavolcano eruptions, appear to be in the one-to-two-year time scale, however aerosol–atmosphere interactions are still poorly understood. Sooty aerosols can have a wide range of properties, as well as complex shapes, making it difficult to determine their evolving atmospheric optical depth value. The conditions present during

351-496: A grenade into the air, which detonates at waist level, increasing the blast radius and harm inflicted by detonation, shock wave, and flying splinters. A relatively recent example of airburst munitions is the VOG-25P "jumping" 40 mm (1.6 in) caseless grenade, which contains a secondary charge to launch it up to 1.5 m (4.9 ft) above its point of impact before the main charge detonates. Another recent development

468-486: A "plausible" estimate on the amount of stratospheric dust injected following a surface burst of 1 Mt is 0.3 teragrams, of which 8 percent would be in the micrometer range. The potential cooling from soil dust was again looked at in 1992, in a US National Academy of Sciences (NAS) report on geoengineering , which estimated that about 10 kg (10 teragrams) of stratospheric injected soil dust with particulate grain dimensions of 0.1 to 1 micrometer would be required to mitigate

585-473: A 1957 report on The Effects of Nuclear Weapons , edited by Samuel Glasstone . A section in that book entitled "Nuclear Bombs and the Weather" states: "The dust raised in severe volcanic eruptions , such as that at Krakatoa in 1883, is known to cause a noticeable reduction in the sunlight reaching the earth ... The amount of [soil or other surface] debris remaining in the atmosphere after the explosion of even

702-544: A decade. The computer-modeled study looked at a nuclear war between the two countries involving 50 Hiroshima-sized nuclear devices on each side, producing massive urban fires and lofting as much as five million metric tons of soot about 50 miles (80 km) into the stratosphere . The soot would absorb enough solar radiation to heat surrounding gases, increasing the breakdown of the stratospheric ozone layer protecting Earth from harmful ultraviolet radiation, with up to 70% ozone loss at northern high latitudes. A "nuclear summer"

819-625: A few weeks prior to the Ivy Mike (10.4 megaton ) bomb test on Elugelab Island, there were concerns that the aerosols lifted by the explosion might cool the Earth. Major Norair Lulejian, USAF , and astronomer Natarajan Visvanathan studied this possibility, reporting their findings in Effects of Superweapons Upon the Climate of the World , the distribution of which was tightly controlled. This report

936-401: A firestorm and produce a pyrocumulus cloud, a cloud that is assumed to have reached upper tropospheric heights, as over its multiple hours of burning, the firestorm released an estimated 1000 times the energy of the bomb. As the incendiary effects of a nuclear explosion do not present any especially characteristic features, it is estimated by those with strategic bombing experience that as

1053-399: A firestorm, the term "nuclear winter" is something of a misnomer. The majority of papers published on the subject state that without qualitative justification, nuclear explosions are the cause of the modeled firestorm effects. The only phenomenon that is modeled by computer in the nuclear winter papers is the climate forcing agent of firestorm-soot, a product which can be ignited and formed by

1170-410: A large greenhouse effect does keep Titan at a much higher temperature than the thermal equilibrium , the anti-greenhouse effect due to the haze reduces the surface temperature by 9 K. Because the greenhouse effect due to other atmospheric components increases it by 21 K, the net effect is that the real surface temperature of Titan (94 K) is 12 K warmer than the effective temperature 82 K (which would be

1287-435: A mechanical time–super quick (MTSQ) artillery fuze set to cause an airburst over a target in very close proximity to the firing gun's position. Set properly, the shell would detonate approximately 10 meters (33 feet) above the ground at ranges of 200 to 1,000 m (660 to 3,280 ft). The term Killer Junior was applied to this technique when used with 105 mm (4.1 in) or 155 mm (6.1 in) howitzers, and

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1404-495: A more thorough knowledge of the atmosphere is necessary to determine their exact nature, extent, and magnitude." In the United States National Research Council (NRC) book Long-Term Worldwide Effects of Multiple Nuclear-Weapons Detonations published in 1975, it states that a nuclear war involving 4,000 Mt from present arsenals would probably deposit much less dust in the stratosphere than

1521-625: A myriad of means. Although rarely discussed, the proponents of the hypothesis state that the same "nuclear winter" effect would occur if 100 large scale conventional firestorms were ignited. A much larger number of firestorms, in the thousands, was the initial assumption of the computer modelers who coined the term in the 1980s. These were speculated to be a possible result of any large scale employment of counter-value airbursting nuclear weapon use during an American-Soviet total war . This larger number of firestorms, which are not in themselves modeled, are presented as causing nuclear winter conditions as

1638-401: A new ice age . The 1966 RAND corporation memorandum The Effects of Nuclear War on the Weather and Climate by E. S. Batten, while primarily analysing potential dust effects from surface bursts, notes that "in addition to the effects of the debris, extensive fires ignited by nuclear detonations might change the surface characteristics of the area and modify local weather patterns ... however,

1755-557: A new Ice Age. Anderson went on to publish a novel based partly on this story in 1961, titling it Twilight World . Similarly in 1985 it was noted by T. G. Parsons that the story "Torch" by C. Anvil, which also appeared in Astounding Science Fiction magazine, but in the April 1957 edition, contains the essence of the "Twilight at Noon"/"nuclear winter" hypothesis. In the story, a nuclear warhead ignites an oil field, and

1872-458: A partial anti-greenhouse effect due to their low thermal opacity and high temperatures. Additionally, ejected dust like that from volcanoes and nuclear fallout after a nuclear war has been suggested to typify an anti-greenhouse effect. Also, the formation of stratospheric sulfur aerosols from volcanic sulfur dioxide emissions has been seen to have a cooling effect on Earth that lasts approximately 1 to 2 years. All of these sources act to create

1989-626: A range of 0.2– 6.4 × 10 g (NAS; TTAPS assumed 2.25 × 10 ). The smoke resulting would be largely opaque to solar radiation but transparent to infrared, thus cooling the Earth by blocking sunlight, but not creating warming by enhancing the greenhouse effect. The optical depth of the smoke can be much greater than unity. Forest fires resulting from non-urban targets could increase aerosol production further. Dust from near-surface explosions against hardened targets also contributes; each megaton-equivalent explosion could release up to five million tons of dust, but most would quickly fall out; high altitude dust

2106-474: A result of any widely used anti-ballistic missile ( ABM-1 Galosh ) system. However, Martin ultimately concludes that it is "unlikely that in the context of a major nuclear war" ozone degradation would be of serious concern. Martin describes views about potential ozone loss and therefore increases in ultraviolet light leading to the widespread destruction of crops, as advocated by Jonathan Schell in The Fate of

2223-527: A result of the smoke inputted into various climate models, with the depths of severe cooling lasting for as long as a decade. During this period, summer drops in average temperature could be up to 20 °C (36 °F) in core agricultural regions of the US, Europe, and China, and as much as 35 °C (63 °F) in Russia. This cooling would be produced due to a 99% reduction in the natural solar radiation reaching

2340-479: A small-scale, regional nuclear war could disrupt the global climate for a decade or more. In a regional nuclear conflict scenario where two opposing nations in the subtropics would each use 50 Hiroshima -sized nuclear weapons (about 15 kilotons each) on major population centers, the researchers estimated as much as five million tons of soot would be released, which would produce a cooling of several degrees over large areas of North America and Eurasia, including most of

2457-543: A study on the experimental measurements of an earlier atmospheric nuclear test as it affected the ozone layer also found that nuclear detonations are exonerated of depleting ozone, after the at first alarming model calculations of the time. Similarly, a 1981 paper found that the models on ozone destruction from one test and the physical measurements taken were in disagreement, as no destruction was observed. In total, about 500 Mt were atmospherically detonated between 1945 and 1971, peaking in 1961–1962, when 340 Mt were detonated in

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2574-492: A temperature structure where a hot upper layer lies above a cold surface, which typifies the anti-greenhouse effect. There has been discussion about a weak anti-greenhouse effect on Mars, where storms carry dust into the upper atmosphere. Evidence for this effect came from Viking 1 measurements made in 1976-77 when in the aftermath of a global storm, the average daytime temperature above the ground dropped by 5 degrees Celsius. Studies using computer simulations have investigated

2691-459: A theory to explain how Martian dust may be formed and how it may reach global proportions." In the same year Alexander Ginzburg, an employee in Golitsyn's institute, developed a model of dust storms to describe the cooling phenomenon on Mars. Golitsyn felt that his model would be applicable to soot after he read a 1982 Swedish magazine dedicated to the effects of a hypothetical nuclear war between

2808-467: A three-dimensional global circulation model. (Two years later Alexandrov disappeared under mysterious circumstances). Richard Turco and Starley L. Thompson were both critical of the Soviet research. Turco called it "primitive" and Thompson said it used obsolete US computer models. Later they were to rescind these criticisms and instead applauded Alexandrov's pioneering work, saying that the Soviet model shared

2925-563: A year earlier by Luis Alvarez in 1980. An NRC study panel on the topic met in December 1981 and April 1982 in preparation for the release of the NRC's The Effects on the Atmosphere of a Major Nuclear Exchange , published in 1985. As part of a study on the creation of oxidizing species such as NOx and ozone in the troposphere after a nuclear war, launched in 1980 by Ambio , a journal of

3042-477: Is " rainout ", both during the "fire-driven convective column" phase, which produces " black rain " near the fire site, and rainout after the convective plume 's dispersal, where the smoke is no longer concentrated and thus "wet removal" is believed to be very efficient. However, these efficient removal mechanisms in the troposphere are avoided in the Robock 2007 study, where solar heating is modeled to quickly loft

3159-474: Is a computer programmable air burst grenade with fire control system . Grenade launchers using this technology include the XM29 , XM307 , PAPOP , Mk 47 Striker , XM25 , Barrett XM109 , K11 , QTS-11 , Norinco LG5 / QLU-11 , and Multi Caliber Individual Weapon System . Orbital ATK developed air burst rounds for autocannons . The air burst is usually 100 to 1,000 m (330 to 3,280 ft) above

3276-446: Is a hypothesized scenario in which, after a nuclear winter caused by aerosols inserted into the atmosphere that would prevent sunlight from reaching lower levels or the surface, has abated, a greenhouse effect then occurs due to carbon dioxide released by combustion and methane released from the decay of the organic matter such as corpses that froze during the nuclear winter. Another more sequential hypothetical scenario, following

3393-496: Is an ideal case and represents the maximum impact the anti-greenhouse effect can have and will not be the impact for a real planet or large moon. Earlier discussions in the scientific community pre-dating the current definition established by Dr. Christopher McKay in 1991 referred to the anti-greenhouse effect as a precursor to the Late Precambrian glaciation, describing it more as a carbon sequestration process. This

3510-508: Is described in a 2013 report by the Defense Threat Reduction Agency as the initial study of the "nuclear winter" concept. It indicated no appreciable chance of explosion-induced climate change. The implications for civil defense of numerous surface bursts of high yield hydrogen bomb explosions on Pacific Proving Ground islands such as those of Ivy Mike in 1952 and Castle Bravo (15 Mt) in 1954 were described in

3627-544: Is determined primarily by the haze production rate. If haze production increases, opacity of the haze increases, resulting in more cooling of the surface temperature. Additionally, the presence of this organic haze is the cause of the temperature inversion in Titan's stratosphere. The presence of an organic haze in Earth's Archean atmosphere was first suggested in 1983 and could have been responsible for an anti-greenhouse effect. This hypothesis stems from attempts at resolving

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3744-461: Is estimated at 0.1–1 million tons per megaton-equivalent of explosion. Burning of crude oil could also contribute substantially. Anti-greenhouse effect This effect has been discovered to exist on Saturn 's moon Titan . In Titan's stratosphere, a haze composed of organic aerosol particles simultaneously absorbs solar radiation and is nearly transparent to infrared energy from Titan's surface. This acts to reduce solar energy reaching

3861-457: Is larger than the other, there is an energy imbalance and the temperature of an object will change to reestablish a balance. Energy sources across the whole electromagnetic spectrum need to be accounted for when calculating the energy balance. In the case of Earth, for example, a balance is struck between incoming shortwave radiation from the Sun and outgoing longwave radiation from the surface and

3978-414: Is no longer the current usage of the term, which emphasizes surface cooling due to high-altitude absorption of solar radiation. The negative greenhouse effect is a phenomenon that can produce localized, rather than planetary, cooling. Whereas the anti-greenhouse effect involves an overall temperature inversion in the stratosphere, the negative greenhouse effect involves a localized temperature inversion in

4095-410: Is no rain to wash it out. This aerosol of particles could heat the stratosphere and prevent a portion of the sun's light from reaching the surface, causing surface temperatures to drop drastically. In this scenario it is predicted that surface air temperatures would be the same as, or colder than, a given region's winter for months to years on end. The modeled stable inversion layer of hot soot between

4212-502: Is similar in shape to the letter Y when viewed from the side (see sliced view). Airbursting also minimizes fallout by keeping the fireball from touching the ground, limiting the amount of debris that is vaporized and drawn up in the radioactive debris cloud. For the Hiroshima bomb , an air burst 550 to 610 m (1,800 to 2,000 ft) above the ground was chosen "to achieve maximum blast effects, and to minimize residual radiation on

4329-517: Is the Stefan–Boltzmann constant , T s u r f {\displaystyle T_{surf}} is the surface temperature, and O L R {\displaystyle OLR} is the outgoing longwave radiation from the haze in the upper atmosphere. Since the haze is not a good absorber of this longwave radiation, it can be assumed to all pass through out to space. The incoming solar energy must be scaled down to account for

4446-435: Is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target. The principal military advantage of an air burst over a ground burst is that the energy from the explosion, including any shell fragments , is distributed more evenly over a wider area; however, the peak energy is lower at ground zero . The shrapnel shell

4563-514: Is the fraction of the solar energy that is absorbed by the haze. Replacing O L R {\displaystyle OLR} with σ {\displaystyle \sigma } T s u r f 4 {\displaystyle T_{surf}^{4}} in the second equation, we have, σ T e 4 = 2 σ T s u r f 4 {\displaystyle \sigma T_{e}^{4}=2\sigma T_{surf}^{4}} and

4680-455: Is the incoming solar energy flux, α {\displaystyle \alpha } is planetary albedo (i.e., reflectivity), and T e {\displaystyle T_{e}} is the effective mean radiating temperature . The incoming solar flux is divided by four to account for time and spatial averaging over the entire planet and the 1 − α {\displaystyle 1-\alpha } factor

4797-528: Is theorized that this haze helped to regulate and stabilize early Earth's climate. Other atmospheric phenomena besides organic hazes act similarly to the anti-greenhouse effect, such as Earth's stratospheric ozone layer and thermosphere, particles formed and emitted from volcanoes, nuclear fallout , and dust in Mars's upper atmosphere. Outside of the Solar system, calculations of the impact of these hazes on

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4914-578: The American Institute of Physics states that the TTAPS team (named for its participants, who had all previously worked on the phenomenon of dust storms on Mars, or in the area of asteroid impact events : Richard P. Turco , Owen Toon , Thomas P. Ackerman, James B. Pollack and Carl Sagan ) announcement of their results in 1983 "was with the explicit aim of promoting international arms control". However, "the computer models were so simplified, and

5031-735: The Andropov instigated Committee of Soviet Scientists in Defence of Peace Against the Nuclear Threat in May 1983, an organization that Golitsyn would later be appointed vice-chairman. The establishment of this committee was done with the expressed approval of the Soviet leadership with the intent "to expand controlled contacts with Western "nuclear freeze" activists ". Having gained this committees approval, in September 1983, Golitsyn published

5148-518: The Naval Research Laboratory , experimentally found that each natural occurrence of a massive wildfire firestorm, much larger than that observed at Hiroshima, can produce minor "nuclear winter" effects, with short-lived, approximately one month of a nearly immeasurable drop in surface temperatures, confined to the hemisphere that they burned in. This is somewhat analogous to the frequent volcanic eruptions that inject sulfates into

5265-492: The Royal Swedish Academy of Sciences , Paul J. Crutzen and John W. Birks began preparing for the 1982 publication of a calculation on the effects of nuclear war on stratospheric ozone, using the latest models of the time. However, they found that as a result of the trend towards more numerous but less energetic, sub-megaton range nuclear warheads (made possible by the march to increase ICBM warhead accuracy ),

5382-449: The faint young Sun paradox , where a reduced solar output in the past must be reconciled with the existence of liquid water on Earth at that time. In order to explain how water could remain in liquid form, it has been proposed that greenhouse gases helped keep Earth warm enough to prevent water from completely freezing. While one hypothesis suggests that only carbon dioxide was responsible for the additional warmth, another hypothesis includes

5499-401: The hypocenter to allow the shockwave of the fission or fusion driven explosion to bounce off the ground and back into itself, combining two wave fronts and creating a shockwave that is more forceful than the one resulting from a detonation at ground level. This " mach stem " only occurs near ground level, exists around the entire perimeter of the expanding wave front near ground level, and

5616-626: The ozone present in this part of the atmosphere. Ozone depletion would allow a much greater intensity of harmful ultraviolet radiation from the sun to reach the ground. A 2008 study by Michael J. Mills et al., published in the Proceedings of the National Academy of Sciences , found that a nuclear weapons exchange between Pakistan and India using their current arsenals could create a near-global ozone hole , triggering human health problems and causing environmental damage for at least

5733-406: The ozone layer was losing credibility. It was within this context that the climatic effects of soot from fires became the new focus of the climatic effects of nuclear war. In these model scenarios, various soot clouds containing uncertain quantities of soot were assumed to form over cities, oil refineries , and more rural missile silos . Once the quantity of soot is decided upon by the researchers,

5850-618: The 1950s–1960s, in which he attempted to model the movement and longevity of a plume of lunar soil. After the publication of "Twilight at Noon" in 1982, the TTAPS team have said that they began the process of doing a 1-dimensional computational modeling study of the atmospheric consequences of nuclear war/soot in the stratosphere, though they would not publish a paper in Science magazine until late-December 1983. The phrase "nuclear winter" had been coined by Turco just prior to publication. In this early paper, TTAPS used assumption-based estimates on

5967-401: The 1970s, in 1974, John Hampson suggested in the journal Nature that due to the creation of atmospheric NOx by nuclear fireballs , a full-scale nuclear exchange could result in depletion of the ozone shield, possibly subjecting the earth to ultraviolet radiation for a year or more. In 1975, Hampson's hypothesis "led directly" to the United States National Research Council (NRC) reporting on

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6084-416: The 1971 Mars 3 lander determined that temperatures on the surface of the red planet were considerably colder than temperatures at the top of the dust cloud. Following these observations, Golitsyn received two telegrams from astronomer Carl Sagan , in which Sagan asked Golitsyn to "explore the understanding and assessment of this phenomenon". Golitsyn recounts that it was around this time that he had "proposed

6201-400: The Earth , as highly unlikely. More recent accounts on the specific ozone layer destruction potential of NOx species are much less than earlier assumed from simplistic calculations, as "about 1.2 million tons" of natural and anthropogenic generated stratospheric NOx is believed to be formed each year according to Robert P. Parson in the 1990s. The first published suggestion that cooling of

6318-618: The Krakatoa eruption, judging that the effect of dust and oxides of nitrogen would probably be slight climatic cooling which "would probably lie within normal global climatic variability, but the possibility of climatic changes of a more dramatic nature cannot be ruled out". In the 1985 report, The Effects on the Atmosphere of a Major Nuclear Exchange , the Committee on the Atmospheric Effects of Nuclear Explosions argues that

6435-552: The USSR and the US. Golitsyn would use Ginzburg's largely unmodified dust-cloud model with soot assumed as the aerosol in the model instead of soil dust and in an identical fashion to the results returned, when computing dust-cloud cooling in the Martian atmosphere, the cloud high above the planet would be heated while the planet below would cool drastically. Golitsyn presented his intent to publish this Martian-derived Earth-analog model to

6552-525: The amount of energy that is lost by being reflected to space since it is not within the planet-atmosphere system. In the upper atmosphere, the energy balance is as follows, S 4 ( 1 − α ) ≡ σ T e 4 = O L R + σ T s u r f 4 {\displaystyle {\frac {S}{4}}(1-\alpha )\equiv \sigma T_{e}^{4}=OLR+\sigma T_{surf}^{4}} where S {\displaystyle S}

6669-527: The anti-greenhouse organic haze. The haze is formed when the ratio of methane to carbon dioxide exceeds roughly 0.1. It is posited that the organic haze allowed the creation of a negative feedback loop to stabilize the climate on Archean Earth. If temperatures increased in Archean Earth, methane production would increase due to methanogens' possible preference for warmer temperatures (see thermophiles ). Increasing temperatures would also increase

6786-500: The atmosphere by the United States and Soviet Union. During this peak, with the multi-megaton range detonations of the two nations nuclear test series, in exclusive examination, a total yield estimated at 300 Mt of energy was released. Due to this, 3 × 10 additional molecules of nitric oxide (about 5,000 tons per Mt, 5 × 10 grams per megaton) are believed to have entered the stratosphere, and while ozone depletion of 2.2 percent

6903-473: The atmosphere would...change considerably over a large fraction of the Northern Hemisphere, which will probably lead to important changes in land surface temperatures and wind systems." An implication of their work was that a successful nuclear decapitation strike could have severe climatic consequences for the perpetrator. After reading a paper by N. P. Bochkov and E. I. Chazov , published in

7020-405: The atmosphere. After establishing a component's energy balance, a temperature can be derived. In the most extreme case, suppose that a planet's upper atmosphere contained a haze that absorbed all sunlight which was not reflected back to space, but at the same time was nearly transparent to infrared longwave radiation. By Kirchhoff's law , since the haze is not a good absorber of infrared radiation,

7137-401: The carbon dioxide loss through weathering due to an assumed increase in precipitation, leading to decrease carbon dioxide concentrations. This would lead to a higher methane to carbon dioxide ratio and would stimulate the production of the organic haze. This increase in organic haze production would lead to increased opacity of the atmosphere to sunlight, decreased amounts of solar energy reaching

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7254-435: The city was a firestorm hazard, the same fire ferocity and building damage produced at Hiroshima by one 16-kiloton nuclear bomb from a single B-29 bomber could have been produced instead by the conventional use of about 1.2 kilotons of incendiary bombs from 220 B-29s distributed over the city. While the firestorms of Dresden and Hiroshima and the mass fires of Tokyo and Nagasaki occurred within mere months in 1945,

7371-571: The climate could be an effect of a nuclear war, appears to have been originally put forth by Poul Anderson and F. N. Waldrop in their story "Tomorrow's Children", in the March 1947 issue of the Astounding Science Fiction magazine. The story, primarily about a team of scientists hunting down mutants , warns of a " Fimbulwinter " caused by dust that blocked sunlight after a recent nuclear war and speculated that it may even trigger

7488-416: The climate effects of these soot clouds are then modeled. The term "nuclear winter" was a neologism coined in 1983 by Richard P. Turco in reference to a one-dimensional computer model created to examine the "nuclear twilight" idea. This model projected that massive quantities of soot and smoke would remain aloft in the air for on the order of years, causing a severe planet-wide drop in temperature. After

7605-545: The conventional bombing of Hamburg , and the Hiroshima firestorm in World War II as example cases where soot might have been injected into the stratosphere, alongside modern observations of natural, large-area wildfire -firestorms. "Nuclear winter", or as it was initially termed, "nuclear twilight", began to be considered as a scientific concept in the 1980s after it became clear that an earlier hypothesis predicting that fireball generated NOx emissions would devastate

7722-516: The cooling effect of firestorms, independent of the nuclear winter computer model projections. Currently, from satellite tracking data, it appears that stratospheric smoke aerosols dissipate in a time span under approximately two months. The existence of a tipping point into a new stratospheric condition where the aerosols would not be removed within this time frame remains to be determined. The nuclear winter scenario assumes that 100 or more city firestorms are ignited by nuclear explosions , and that

7839-494: The creation of the soot are believed to be considerably important as to their final properties, with soot generated on the more efficient spectrum of burning efficiency considered almost "elemental carbon black ," while on the more inefficient end of the burning spectrum, greater quantities of partially burnt /oxidized fuel are present. These partially burnt "organics" as they are known, often form tar balls and brown carbon during common lower-intensity wildfires, and can also coat

7956-765: The cumulative products of 100 of these firestorms could cool the global climate by approximately 1 °C (1.8 °F), largely eliminating the magnitude of anthropogenic global warming for the next roughly two or three years. Robock and his collaborators have modeled the effect on global food production, and project that the injection of more than 5 Tg of soot into the stratosphere would lead to mass food shortages persisting for several years. According to their model, livestock and aquatic food production would be unable to compensate for reduced crop output in almost all countries, and adaptation measures such as food waste reduction would have limited impact on increasing available calories. As nuclear devices need not be detonated to ignite

8073-496: The data on smoke and other aerosols were still so poor, that the scientists could say nothing for certain". In 1981, William J. Moran began discussions and research in the National Research Council (NRC) on the airborne soil/dust effects of a large exchange of nuclear warheads, having seen a possible parallel in the dust effects of a war with that of the asteroid-created K-T boundary and its popular analysis

8190-412: The decay of dead organic matter. The detonations would also insert nitrogen oxides into the stratosphere that would then deplete the ozone layer around the Earth. Other more straightforward hypothetical versions exist of the hypothesis that nuclear winter might give way to a nuclear summer. The high temperatures of the nuclear fireballs could destroy the ozone gas of the middle stratosphere. In 1952,

8307-450: The effect of nuclear twilight on agriculture. Crutzen and Birks' calculations suggested that smoke particulates injected into the atmosphere by fires in cities, forests and petroleum reserves could prevent up to 99 percent of sunlight from reaching the Earth's surface. This darkness, they said, could exist "for as long as the fires burned", which was assumed to be many weeks, with effects such as: "The normal dynamic and temperature structure of

8424-706: The estimated altitude of the target. During World War II a " proximity fuze " was developed for antiaircraft use, controlled by a Doppler radar device within the shell that caused it to explode when near the target. The idea was later adapted for use against ground targets. During the Vietnam War , air bursting shells were used to great affect to defend bases. This tactic was known as "Killer Junior" when referring to 105 mm (4.1 in) or 155 mm (6.1 in) shells, and "Killer Senior" when employed with larger howitzers . Some anti-personnel bounding mines such as Germany's World War II " Bouncing Betty " fire

8541-434: The failure of the predictions on the effects of the 1991 Kuwait oil fires that were made by the primary team of climatologists that advocate the hypothesis, over a decade passed without new published papers on the topic. More recently, the same team of prominent modellers from the 1980s have begun again to publish the outputs of computer models. These newer models produce the same general findings as their old ones, namely that

8658-546: The fate of the Earth, as plant and aquatic life going extinct. In the same year, 1982, Australian physicist Brian Martin , who frequently corresponded with John Hampson who had been greatly responsible for much of the examination of NOx generation, penned a short historical synopsis on the history of interest in the effects of the direct NOx generated by nuclear fireballs, and in doing so, also outlined Hampson's other non-mainstream viewpoints, particularly those relating to greater ozone destruction from upper-atmospheric detonations as

8775-413: The firestorms lift large amounts of sooty smoke into the upper troposphere and lower stratosphere by the movement offered by the pyrocumulonimbus clouds that form during a firestorm. At 10–15 kilometres (6–9 miles) above the Earth's surface, the absorption of sunlight could further heat the soot in the smoke, lifting some or all of it into the stratosphere , where the smoke could persist for years if there

8892-610: The first computer model on the nascent "nuclear winter" effect in the widely read Herald of the Russian Academy of Sciences . On 31 October 1982, Golitsyn and Ginsburg's model and results were presented at the conference on "The World after Nuclear War", hosted in Washington, D.C. Both Golitsyn and Sagan had been interested in the cooling on the dust storms on the planet Mars in the years preceding their focus on "nuclear winter". Sagan had also worked on Project A119 in

9009-517: The first suggestions of alterations in short-term climate from fires presumed to occur following a nuclear war. Later in the same year, the special issue of Ambio devoted to the possible environmental consequences of nuclear war by Crutzen and Birks was titled "The Atmosphere after a Nuclear War: Twilight at Noon", and largely anticipated the nuclear winter hypothesis. The paper looked into fires and their climatic effect and discussed particulate matter from large fires, nitrogen oxide, ozone depletion and

9126-468: The grain-growing regions. The cooling would last for years, and, according to the research, could be "catastrophic", disrupting agricultural production and food gathering in particular in higher latitude countries. Nuclear detonations produce large amounts of nitrogen oxides by breaking down the air around them. These are then lifted upwards by thermal convection. As they reach the stratosphere, these nitrogen oxides are capable of catalytically breaking down

9243-519: The ground as it was hoped U.S. troops would soon occupy the city ". Some nuclear weapons have a contact preclusion fuzing feature to prevent the backup contact fuze from detonating the weapon if the air burst fuzing fails. In conventional warfare, air bursts are used primarily against infantry in the open or unarmored targets, as the resulting fragments cover a large area but will not penetrate armor or field fortifications. In nuclear warfare , air bursts are used against soft targets (i.e. lacking

9360-430: The hardened construction required to survive overpressure from a nuclear explosion) such as cities in countervalue targeting, or airfields, radar systems and mobile ICBMs in counterforce targeting. Killer Junior and Killer Senior are techniques of employing artillery direct fire air bursts, first developed during the Vietnam War . The technique involves a howitzer firing a high explosive (HE) shell using

9477-543: The haze will also not be a good emitter of infrared radiation and will emit a small amount in this part of the spectrum both out to space and towards the planet's surface. By the Stefan–Boltzmann law , the planet emits energy directly proportional to the fourth power of surface temperature. At the surface, the energy balance is as follows, σ T s u r f 4 = O L R {\displaystyle \sigma T_{surf}^{4}=OLR} where σ {\displaystyle \sigma }

9594-525: The ignition of 100 firestorms, each comparable in intensity to that observed in Hiroshima in 1945, could produce a "small" nuclear winter. These firestorms would result in the injection of soot (specifically black carbon ) into the Earth's stratosphere, producing an anti-greenhouse effect that would lower the Earth's surface temperature . The severity of this cooling in Alan Robock's model suggests that

9711-436: The impact of photochemical hazes on exoplanets' thermal structure. Applying this model to hot Jupiters, scientists found that the inclusion of haze for HD 189733 b led to an expansion of the atmosphere, helping to explain an observed steep transit signature in the electromagnetic spectrum. Also, the model for HD 209458 b predicted both photochemical haze and objects like clouds. Air burst An air burst or airburst

9828-450: The largest nuclear weapons is probably not more than about one percent or so of that raised by the Krakatoa eruption. Further, solar radiation records reveal that none of the nuclear explosions to date has resulted in any detectable change in the direct sunlight recorded on the ground." The US Weather Bureau in 1956 regarded it as conceivable that a large enough nuclear war with megaton-range surface detonations could lift enough soil to cause

9945-413: The largest possible number with a single burst. When infantry moved into deep trenches, shrapnel shells were rendered useless, and high-explosive shells were used to attack field fortifications and troops in the open. The time fuses for the shells could be set to function on contact or in the air, or at a certain time after contact. Early anti-aircraft warfare used time fuses to function when they reached

10062-542: The mass of soot injected into the stratosphere by 100 firestorms (one to five million metric tons ) would have been detectable with technical instruments in WWII, five percent of that would not have been possible to observe at that time. The exact timescale for how long this smoke remains, and thus how severely this smoke affects the climate once it reaches the stratosphere, is dependent on both chemical and physical removal processes. The most important physical removal mechanism

10179-506: The models of ozone depletion following nuclear war in the book Long-Term Worldwide Effects of Multiple Nuclear-Weapons Detonations . In the section of this 1975 NRC book pertaining to the issue of fireball generated NOx and ozone layer loss therefrom, the NRC presented model calculations from the early-to-mid 1970s on the effects of a nuclear war with the use of large numbers of multi-megaton yield detonations, which returned conclusions that this could reduce ozone levels by 50 percent or more in

10296-407: The more intense and conventionally lit Hamburg firestorm occurred in 1943. Despite the separation in time, ferocity and area burned, leading modelers of the hypothesis state that these five fires potentially placed five percent as much smoke into the stratosphere as the hypothetical 100 nuclear-ignited fires discussed in modern models. While it is believed that the modeled climate-cooling-effects from

10413-488: The northern hemisphere. However, independent of the computer models presented in the 1975 NRC works, a paper in 1973 in the journal Nature depicts the stratospheric ozone levels worldwide overlaid upon the number of nuclear detonations during the era of atmospheric testing. The authors conclude that neither the data nor their models show any correlation between the approximate 500 Mt in historical atmospheric testing and an increase or decrease of ozone concentration. In 1976,

10530-400: The ozone layer danger was "not very significant". It was after being confronted with these results that they "chanced" upon the notion, as "an afterthought" of nuclear detonations igniting massive fires everywhere and, crucially, the smoke from these conventional fires then going on to absorb sunlight, causing surface temperatures to plummet. In early 1982, the two circulated a draft paper with

10647-487: The presence of both carbon dioxide and methane. One model found that methane in the postbiotic Archean could have existed at a mixing ratio of 1,000 ppm or higher, while the carbon dioxide could be as low as 5,000 ppm to still prevent Earth from freezing over, about 12 times the amount in 2022. However, at this 0.2 ratio of methane to carbon dioxide, products deriving from methane photolysis can polymerize to form long-chain molecules that can aggregate into particles, forming

10764-552: The products combine into longer chains and bigger molecules. These methane-derived polymers can be made of polycyclic aromatic hydrocarbons (PAHs) and polyacetylene. The distribution of these polymers is not vertically uniform in Titan's atmosphere, however. The nitrile and polyacetylene polymers are formed in the upper atmosphere while the PAH polymers are created in the stratosphere. These polymers then aggregate to form haze particles. The opacity to sunlight of this organic haze on Titan

10881-512: The purer black carbon particles. However, as the soot of greatest importance is that which is injected to the highest altitudes by the pyroconvection of the firestorm – a fire being fed with storm-force winds of air – it is estimated that the majority of the soot under these conditions is the more oxidized black carbon. A study presented at the annual meeting of the American Geophysical Union in December 2006 found that even

10998-411: The ratio T s u r f / T e {\displaystyle T_{surf}/T_{e}} equals ( 0.5 ) 1 / 4 {\displaystyle \left(0.5\right)^{1/4}} or 0.84. This means that the surface temperature is reduced from the effective mean radiating temperature by 16%, which is a potentially significant cooling effect. This

11115-401: The removal are dependent on the ability of atmospheric chemistry to oxidize the carbonaceous component of the smoke, via reactions with oxidative species such as ozone and nitrogen oxides , both of which are found at all levels of the atmosphere, and which also occur at greater concentrations when air is heated to high temperatures. Historical data on residence times of aerosols, albeit

11232-402: The same basic data", with only minor model-code differences. They skip the modeling steps of assessing the possibility of fire and the initial fire plumes and instead start the modeling process with a "spatially uniform soot cloud" which has found its way into the atmosphere. Although never openly acknowledged by the multi-disciplinary team who authored the most popular 1980s TTAPS model, in 2011

11349-443: The same edition of Ambio that carried Crutzen and Birks's paper "Twilight at Noon", Soviet atmospheric scientist Georgy Golitsyn applied his research on Mars dust storms to soot in the Earth's atmosphere. The use of these influential Martian dust storm models in nuclear winter research began in 1971, when the Soviet spacecraft Mars 2 arrived at the red planet and observed a global dust cloud. The orbiting instruments together with

11466-517: The settling out of most of the aerosols in 1–3 years, the cooling effect would be overcome by a heating effect from greenhouse warming , which would raise surface temperatures rapidly by many degrees, enough to cause the death of much if not most of the life that had survived the cooling, much of which is more vulnerable to higher-than-normal temperatures than to lower-than-normal temperatures. The nuclear detonations would release CO 2 and other greenhouse gases from burning, followed by more released from

11583-433: The soot into the stratosphere, "detraining" or separating the darker soot particles from the fire clouds' whiter water condensation . Once in the stratosphere, the physical removal mechanisms affecting the timescale of the soot particles' residence are how quickly the aerosol of soot collides and coagulates with other particles via Brownian motion , and falls out of the atmosphere via gravity-driven dry deposition , and

11700-629: The soot produced "screens out part of the sun's radiation", resulting in Arctic temperatures for much of the population of North America and the Soviet Union. The 1988 Air Force Geophysics Laboratory publication, An assessment of global atmospheric effects of a major nuclear war by H. S. Muench, et al., contains a chronology and review of the major reports on the nuclear winter hypothesis from 1983 to 1986. In general, these reports arrive at similar conclusions as they are based on "the same assumptions,

11817-408: The soot's injection height is controlled by the rate of energy release from the firestorm's fuel, not the size of an initial nuclear explosion. For example, the mushroom cloud from the bomb dropped on Hiroshima reached a height of six kilometers (middle troposphere) within a few minutes and then dissipated due to winds, while the individual fires within the city took almost three hours to form into

11934-412: The stratosphere and thereby produce minor, even negligible, volcanic winter effects. A suite of satellite and aircraft-based firestorm-soot-monitoring instruments are at the forefront of attempts to accurately determine the lifespan, quantity, injection height, and optical properties of this smoke. Information regarding all of these properties is necessary to truly ascertain the length and severity of

12051-482: The surface and lets infrared energy escape, cooling Titan's surface. Titan has both a greenhouse and an anti-greenhouse effect which compete with one another. The greenhouse effect warms Titan by 21 K while the anti-greenhouse effect cools Titan by 9 K, so the net warming is 12 K (= 21 K - 9 K). It has been suggested that Earth potentially had a similar haze in the Archean eon, causing an anti-greenhouse effect. It

12168-467: The surface of the planet in the first few years, gradually clearing over the course of several decades. On the fundamental level, since the advent of photographic evidence of tall clouds were captured, it was known that firestorms could inject soot smoke/ aerosols into the stratosphere, but the longevity of this slew of aerosols was a major unknown. Independent of the team that continue to publish theoretical models on nuclear winter, in 2006, Mike Fromm of

12285-433: The surface temperature in the absence of any atmosphere, assuming constant albedo ). In the ideal anti-greenhouse case described above, the maximum impact of the organic haze on Titan is (1-0.84) × {\displaystyle \times } 82 K = 13 K. This is higher than the 9 K found on Titan. The organic haze is formed through the polymerization of methane photolysis products and nitriles , meaning

12402-420: The surface, and thus decreases in surface temperature, thus negating the initial increase in surface temperature. One estimation of the anti-greenhouse effect on Archean Earth calculated the impact to be up to about 20 K in surface cooling. In the modern state of Earth's atmosphere, there are a few sources of an anti-greenhouse effect. It has been suggested that stratospheric ozone and Earth's thermosphere create

12519-477: The term Killer Senior applied to its use with the M115 203 mm (8.0 in) howitzer . The term "Killer" came from the call-sign of the battery which developed the technique. The technique was later perfected by Lieutenant Colonel Robert Dean, commander of the 1st Battalion, 8th Field Artillery Regiment , of the 25th Infantry Division Artillery. Killers Junior and Senior were developed as alternatives to

12636-447: The thermal structure of exoplanets have been conducted. To understand how the anti-greenhouse effect impacts a planet or large moon with its host star as an external source of energy, an energy budget can be calculated, similar to how it is done for Earth. For each component in the system, incoming energy needs to equal outgoing energy to uphold the conservation of energy and remain at a constant temperature. If one energy contributor

12753-406: The time it takes for the " phoretic effect " to move coagulated particles to a lower level in the atmosphere. Whether by coagulation or the phoretic effect, once the aerosol of smoke particles are at this lower atmospheric level, cloud seeding can begin, permitting precipitation to wash the smoke aerosol out of the atmosphere by the wet deposition mechanism. The chemical processes that affect

12870-428: The total smoke and dust emissions that would result from a major nuclear exchange, and with that, began analyzing the subsequent effects on the atmospheric radiation balance and temperature structure as a result of this quantity of assumed smoke. To compute dust and smoke effects, they employed a one-dimensional microphysics/radiative-transfer model of the Earth's lower atmosphere (up to the mesopause), which defined only

12987-415: The troposphere and high stratosphere that produces the anti-greenhouse effect was dubbed the "Smokeosphere" by Stephen Schneider et al. in their 1988 paper. Although it is common in the climate models to consider city firestorms, these need not be ignited by nuclear devices; more conventional ignition sources can instead be the spark of the firestorms. Prior to the previously mentioned solar heating effect,

13104-502: The troposphere. Both effects increase outgoing thermal emissions—locally in the case of a negative greenhouse effect and globally in the case of the anti-greenhouse effect. The organic haze in Titan's stratosphere absorbs 90% of the solar radiation reaching Titan, but is inefficient at trapping infrared radiation generated by the surface. This is due to Titan's atmospheric window occurring from roughly 16.5 to 25 micrometers. Although

13221-411: The vertical characteristics of the global climate perturbation. Interest in the environmental effects of nuclear war, however, had continued in the Soviet Union after Golitsyn's September paper, with Vladimir Alexandrov and G. I. Stenchikov also publishing a paper in December 1983 on the climatic consequences, although in contrast to the contemporary TTAPS paper, this paper was based on simulations with

13338-405: The warming from a doubling of atmospheric carbon dioxide, that is, to produce ~2 °C of cooling. In 1969, Paul Crutzen discovered that oxides of nitrogen (NOx) could be an efficient catalyst for the destruction of the ozone layer/ stratospheric ozone . Following studies on the potential effects of NOx generated by engine heat in stratosphere flying Supersonic Transport (SST) airplanes in

13455-510: The weaknesses of all the others. In 1984, the World Meteorological Organization (WMO) commissioned Golitsyn and N. A. Phillips to review the state of the science. They found that studies generally assumed a scenario where half of the world's nuclear weapons would be used, ~5000 Mt, destroying approximately 1,000 cities, and creating large quantities of carbonaceous smoke – 1– 2 × 10 g being most likely, with

13572-634: Was invented by Henry Shrapnel of the British Army in about 1780 to increase the effectiveness of canister shot . It was used in the later Napoleonic wars and stayed in use until superseded in Artillery of World War I . Modern shells, though sometimes called "shrapnel shells", actually produce fragments and splinters , not shrapnel. Air bursts were used in the First World War to shower enemy positions and men with shrapnel balls to kill

13689-414: Was noted in 1963, the decline had started prior to 1961 and is believed to have been caused by other meteorological effects . In 1982 journalist Jonathan Schell in his popular and influential book The Fate of the Earth , introduced the public to the belief that fireball generated NOx would destroy the ozone layer to such an extent that crops would fail from solar UV radiation and then similarly painted

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