Editing Nuclear winter (section)

=== 1980s ===
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, 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.<ref name="babel.hathitrust.org" />

Although never openly acknowledged by the multi-disciplinary team who authored the most popular 1980s TTAPS model, in 2011 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 event]]s: [[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".<ref name="history.aip.org">{{cite web|title=Wintry Doom |url=http://history.aip.org/history/climate/Winter.htm|website=history.aip.org|access-date=2016-12-02 |archive-url=https://web.archive.org/web/20161202235031/http://history.aip.org/history/climate/Winter.htm |archive-date=2016-12-02|url-status=live}}</ref> However, "the computer models were so simplified, and the data on smoke and other aerosols were still so poor, that the scientists could say nothing for certain".<ref name="history.aip.org"/>

In 1981, William J. Moran began discussions and research in the [[National Research Council (United States)|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 a year earlier by [[Luis Walter Alvarez|Luis Alvarez]] in 1980.{{sfn|Committee on the Atmospheric Effects of Nuclear Explosions|1985|loc="Appendix: Evolution of Knowledge About Long-Term Nuclear Effects"|p=186}} 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.{{sfn|Committee on the Atmospheric Effects of Nuclear Explosions |1985|p={{page needed|date=September 2021}}}}

As part of a study on the creation of [[Oxidizing agent|oxidizing species]] such as NOx and ozone in the troposphere after a nuclear war,<ref name="Nuclear Winter Documentary 1984">{{Citation |title=On the 8th Day – Nuclear Winter Documentary |date=1984 |url=https://www.youtube.com/watch?v=WCTKcd2Ko98 |access-date=2023-12-15 |language=en}}.</ref> launched in 1980 by ''[[Ambio]]'', a journal of 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 [[Circular Error Probable|accuracy]]), the ozone layer danger was "not very significant".<ref name="bmartin.cc1"/>

It was after being confronted with these results that they "chanced" upon the notion, as "an afterthought"<ref name="Nuclear Winter Documentary 1984" /> 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.<ref name="bmartin.cc1"/> In early 1982, the two circulated a draft paper with the first suggestions of alterations in short-term climate from fires presumed to occur following a nuclear war.{{sfn|Committee on the Atmospheric Effects of Nuclear Explosions |1985|p={{page needed|date=September 2021}}}} 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.<ref name="crutzen" /> The paper looked into fires and their climatic effect and discussed particulate matter from large fires, nitrogen oxide, ozone depletion and 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 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."<ref name=crutzen /> 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 [[Yevgeniy Chazov|E. I. Chazov]],<ref>{{cite book |author=Chazov |first1=E. I. |title=The Aftermath: the human and ecological consequences of nuclear war |last2=Vartanian |first2=M. E. |date=1983 |publisher=Pantheon Books |isbn=978-0-394-72042-5 |editor=Peterson |editor-first=Jeannie |location=New York |pages=[https://archive.org/details/aftermathhuman00pete/page/155 155–163] |language=en |chapter=Effects on human behaviour |chapter-url=https://archive.org/details/aftermathhuman00pete |chapter-url-access=registration}}</ref> published in the same edition of ''Ambio'' that carried Crutzen and Birks's paper "Twilight at Noon", Soviet atmospheric scientist [[Georgy Golitsyn]] applied his research on [[Climate of Mars#Effect of dust storms|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,<ref name="Vladimir Gubarev 2001">{{cite journal |author=Gubarev |first=Vladimir |author-link=Vladimir Gubarev |date=2001 |title=Tea Drinking in The Academy. Academician G. S. Golitsyn: Agitations Of The Sea And Earth |url=http://www.nkj.ru/archive/articles/5755/ |url-status=live |journal=Science and Life |language=ru |volume=3 |archive-url=https://web.archive.org/web/20110522025535/http://www.nkj.ru/archive/articles/5755/ |archive-date=2011-05-22 |access-date=2009-10-11}}</ref> when the Soviet spacecraft [[Mars 2]] arrived at the red planet and observed a global dust cloud. The orbiting instruments together with 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 a theory{{which|date=December 2016}} to explain how Martian dust may be formed and how it may reach global proportions."<ref name="Vladimir Gubarev 2001"/>

In the same year Alexander Ginzburg,<ref name="journals.co-action.net">{{cite journal |last1=Golitsyn |first1=G. S. |last2=Ginsburg |first2=Alexander S. |date=1985 |title=Comparative estimates of climatic consequences of Martian dust storms and of possible nuclear war |journal=Tellus |volume=378 |issue=3 |pages=173–181 |bibcode=1985TellB..37..173G |doi=10.3402/tellusb.v37i3.15015 |doi-access=free}}</ref> 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 the USSR and the US.<ref name="Vladimir Gubarev 2001"/> 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 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 disarmament|"nuclear freeze" activists]]".<ref>{{cite magazine |author=Zubok |first=Vladislav M. |date=April 1, 2000 |title=Gorbachev's Nuclear Learning |work=Boston Review |url=https://bostonreview.net/world/vladislav-m-zubok-gorbachevs-nuclear-learning |url-status=live |archive-url=https://web.archive.org/web/20160818075324/http://bostonreview.net/world/vladislav-m-zubok-gorbachevs-nuclear-learning |archive-date=18 August 2016 |access-date=21 December 2016}}</ref> Having gained this committees approval, in September 1983, Golitsyn published the first computer model on the nascent "nuclear winter" effect in the widely read ''[[Herald of the Russian Academy of Sciences]]''.<ref name="Тяжелая пыль">{{Cite web |author=Shumeyko |first=Igor |date=2003-10-08 |title=Тяжелая пыль "ядерной зимы" |trans-title=Heavy dust 'nuclear winter' |url=http://www.ng.ru/science/2003-10-08/14_winter.html |url-status=live |archive-url=https://web.archive.org/web/20110617081632/http://www.ng.ru/science/2003-10-08/14_winter.html |archive-date=2011-06-17 |access-date=2009-10-27 |language=ru}}</ref>

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.]]<ref name="journals.co-action.net"/>

Both Golitsyn<ref name="Тяжелая пыль"/> and Sagan<ref>{{cite thesis |author=Rubinson |date=2008 |title=Containing Science: The U.S. National Security State and Scientists' Challenge to Nuclear Weapons during the Cold War |url=https://www.lib.utexas.edu/etd/d/2008/rubinsonp66913/rubinsonp66913.pdf |archive-url=https://web.archive.org/web/20140924041711/https://www.lib.utexas.edu/etd/d/2008/rubinsonp66913/rubinsonp66913.pdf |archive-date=2014-09-24 |type=PhD |first=Paul Harold}}</ref> 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 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,{{Sfn | Badash |2009 | p = {{page needed|date=September 2021}}}} 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 (journal)|Science]]'' magazine until late-December 1983.<ref name="CITEREFTurcoToonAckermanPollack1983">{{cite journal |last1=Turco |first1=R. P. |last2=Toon |first2=O. B. |last3=Ackerman |first3=T. P. |last4=Pollack |first4=J. B. |last5=Sagan |first5=Carl |date=December 23, 1983 |title=Nuclear Winter: Global Consequences of Multiple Nuclear Explosions |journal=Science |volume=222 |issue=4630 |pages=1283–1292 |bibcode=1983Sci...222.1283T |doi=10.1126/science.222.4630.1283 |pmid=17773320 |s2cid=45515251}}</ref> The phrase "nuclear winter" had been coined by Turco just prior to publication.<ref>{{cite journal |author=Dörries |first=Matthias |date=2011 |title=The Politics of Atmospheric Sciences: "Nuclear Winter" and Global Climate Change |url=https://univoak.eu/islandora/object/islandora%3A62598 |journal=Osiris |volume=26 |issue=1 |pages=198–223 |doi=10.1086/661272 |jstor=10.1086/661272) |pmid=21936194 |s2cid=23719340}}</ref> In this early paper, TTAPS used assumption-based estimates on 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 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 a three-dimensional global circulation model.<ref name="Alexandrov, V. V 1983" /> (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.{{Sfn | Badash |2009 | p = 219}} Later they were to rescind these criticisms and instead applauded Alexandrov's pioneering work, saying that the Soviet model shared the weaknesses of all the others.<ref name="babel.hathitrust.org"/>

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–{{val|2|e=14|u=g}} being most likely, with a range of 0.2–{{val|6.4|e=14|u=g}} (NAS; TTAPS assumed {{val|2.25|e=14}}). 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 is estimated at 0.1–1 million tons per megaton-equivalent of explosion. Burning of crude oil could also contribute substantially.<ref>Golitsyn, G. S. and Phillips, N. A. (1986) "Possible climatic consequences of a major nuclear war", ''[[World climate research programme|WCRP]]'', World Meteorological Organization, WCP-113, WMO/TD #99.</ref>

The 1-D radiative-convective models used in these{{which|date=October 2016}} studies produced a range of results, with cooling up to 15–42&nbsp;°C between 14 and 35 days after the war, with a "baseline" of about 20&nbsp;°C. Somewhat more sophisticated calculations using 3-D [[Global climate model|GCMs]] produced similar results: temperature drops of about 20&nbsp;°C, though with regional variations.<ref name="Alexandrov, V. V 1983"/><ref>{{cite journal |last1=Covey |first1=C. |last2=Schneider |first2=S. |last3=Thompson |first3=S. |title=Global atmospheric effects of massive smoke injections from a nuclear war: results from general circulation model simulations |journal=Nature |volume=308 |pages=21–25 |date=March 1984 |issue=5954 |doi=10.1038/308021a0 |bibcode=1984Natur.308...21C |s2cid=4326912 |url=http://climate.envsci.rutgers.edu/pdf/CoveySchneiderThompson.pdf |access-date=2021-09-04 |archive-date=2021-09-04  |archive-url=https://web.archive.org/web/20210904215009/http://climate.envsci.rutgers.edu/pdf/CoveySchneiderThompson.pdf |url-status=live }}</ref>

All{{which|date=October 2016}} calculations show large heating (up to 80&nbsp;°C) at the top of the smoke layer at about {{Cvt|10|km|}}; this implies a substantial modification of the circulation there and the possibility of [[advection]] of the cloud into low latitudes and the southern hemisphere.