Editing Nuclear winter (section)

==General==
"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 [[#Early work|fireball generated NOx]] emissions would devastate the [[ozone layer]] was losing credibility.<ref name=":2" /> It was within this context that the climatic effects of soot from fires became the new focus of the climatic effects of nuclear war.<ref name="Nuclear Winter Documentary 1984" /><ref name="bmartin.cc1">{{cite web |author=Martin |first=Brian |date=1988 |title=John Hampson's warnings of disaster |url=http://www.bmartin.cc/pubs/88Hampson.html |url-status=live |archive-url=https://web.archive.org/web/20141130145905/http://www.bmartin.cc/pubs/88Hampson.html |archive-date=2014-11-30 |access-date=2014-10-03 |website=www.bmartin.cc}}</ref> In these model scenarios, various soot clouds containing uncertain quantities of soot were assumed to form over cities, [[Kuwait oil fires|oil refineries]], and more rural [[missile silo]]s. Once the quantity of soot is decided upon by the researchers, the climate effects of these soot clouds are then modeled.<ref name="babel.hathitrust.org">{{cite report |title=An assessment of global atmospheric effects of a major nuclear conflict |last1=Muench |first1=H. S. |last2=Banta |first2=R. M. |date=10 May 1988 |publisher=Air Force Geophysics Laboratory |last3=Brenner |first3=S. |last4=Chisholm |first4=D. A. |place=Hanscom Air Force Base, Massachusetts |hdl=2027/uc1.31822020694212}}</ref> 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 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 the ignition of 100 firestorms, each comparable in intensity to that observed in [[Hiroshima]] in 1945, could produce a "small" nuclear winter.{{sfn|Toon|Turco|Robock|Bardeen|2007}}<ref>{{cite journal |author=Robock |first1=Alan |last2=Oman |first2=Luke |last3=Stenchikov |first3=Georgiy L. |last4=Toon |first4=Owen B. |last5=Bardeen |first5=Charles |last6=Turco |first6=Richard P. |name-list-style=amp |date=2007 |title=Climatic consequences of regional nuclear conflicts |url=http://climate.envsci.rutgers.edu/pdf/acp-7-2003-2007.pdf |url-status=live |journal=Atmos. Chem. Phys. |volume=7 |issue=8 |pages=2003–12 |bibcode=2007ACP.....7.2003R |doi=10.5194/acp-7-2003-2007 |archive-url=https://web.archive.org/web/20130629153655/http://climate.envsci.rutgers.edu/pdf/acp-7-2003-2007.pdf |archive-date=2013-06-29 |access-date=2007-12-05 |doi-access=free}}</ref> 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 [[Temperature record|Earth's surface temperature]]. The severity of this cooling in [[Alan Robock|Alan Robock's]] model suggests that the cumulative products of 100 of these firestorms could cool the [[global climate]] by approximately 1&nbsp;°C (1.8&nbsp;°F), largely eliminating the magnitude of [[anthropogenic global warming]] for the next roughly two or three years.<ref name="news.nationalgeographic.com">{{cite web |author=Choi |first=Charles Q. |date=2011-02-23 |title=Small Nuclear War Could Reverse Global Warming for Years |url=http://news.nationalgeographic.com/news/2011/02/110223-nuclear-war-winter-global-warming-environment-science-climate-change/ |url-status=dead |archive-url=https://web.archive.org/web/20140916215816/http://news.nationalgeographic.com/news/2011/02/110223-nuclear-war-winter-global-warming-environment-science-climate-change/ |archive-date=2014-09-16 |access-date=2014-09-20 |work=National Geopraphic}}</ref> 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.<ref name=Xia2022>{{Cite journal |last1=Xia |first1=Lili |last2=Robock |first2=Alan |last3=Scherrer |first3=Kim |last4=Harrison |first4=Cheryl S. |last5=Bodirsky |first5=Benjamin Leon |last6=Weindl |first6=Isabelle |last7=Jägermeyr |first7=Jonas |last8=Bardeen |first8=Charles G. |last9=Toon |first9=Owen B. |last10=Heneghan |first10=Ryan |date=2022-08-15 |title=Global food insecurity and famine from reduced crop, marine fishery and livestock production due to climate disruption from nuclear war soot injection |journal=Nature Food |language=en |volume=3 |issue=8 |pages=586–596 |doi=10.1038/s43016-022-00573-0 |pmid=37118594 |s2cid=251601831 |issn=2662-1355|doi-access=free |bibcode=2022NatFd...3..586X |hdl=11250/3039288 |hdl-access=free }}</ref><ref>{{cite journal | last1=Jägermeyr | first1=Jonas | last2=Robock | first2=Alan | last3=Elliott | first3=Joshua | last4=Müller | first4=Christoph | last5=Xia | first5=Lili | last6=Khabarov | first6=Nikolay | last7=Folberth | first7=Christian | last8=Schmid | first8=Erwin | last9=Liu | first9=Wenfeng | last10=Zabel | first10=Florian | last11=Rabin | first11=Sam S. | last12=Puma | first12=Michael J. | last13=Heslin | first13=Alison | last14=Franke | first14=James | last15=Foster | first15=Ian | last16=Asseng | first16=Senthold | last17=Bardeen | first17=Charles G. | last18=Toon | first18=Owen B. | last19=Rosenzweig | first19=Cynthia | title=A regional nuclear conflict would compromise global food security | journal=Proceedings of the National Academy of Sciences | volume=117 | issue=13 | date=2020-03-16 | issn=0027-8424 | doi=10.1073/pnas.1919049117 | pages=7071–7081 | pmid=32179678 | pmc=7132296 | doi-access=free | bibcode=2020PNAS..117.7071J }}</ref>

[[File:How would a nuclear war between Russia and the US affect you personally? - Future of Life Institute.webm|thumb|Simulation of a nuclear war between Russia and the US based on Xia et al.<ref name="Xia2022" /> and others: Over 80% of the global population would starve to death unless they succumbed to other causes sooner. The death toll in the US, Russia, Europe, and China would be approximately 99%, with over 90% of fatalities occurring in countries not directly involved in the nuclear exchange.]]

As nuclear devices need not be detonated to ignite a firestorm, the term "nuclear winter" is something of a misnomer.{{Sfn | Badash |2009 | pp = 242–244}} 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 a myriad of means.{{Sfn | Badash |2009 | pp = 242–244}} 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.<ref name="ReferenceC">{{harvnb|Toon|Turco|Robock|Bardeen|2007|p=1998}}. "...fires occurred within a few months of each other in 1945, the Hamburg mass fire occurred in 1943. These five fires potentially placed 5% as much smoke into the stratosphere as our hypothetical nuclear fires. The optical depth resulting from placing 5 Tg of soot into the global stratosphere is about 0.07, which would be easily observable even with techniques available in WWII."</ref>

A much larger number of firestorms, in the thousands,{{failed verification|date=December 2016}} 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 [[air burst|airbursting]] [[nuclear weapon]] use during an American-Soviet [[total war]]. This larger number of firestorms, which are not in themselves modeled,<ref name="babel.hathitrust.org" /> are presented as causing nuclear winter conditions as 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&nbsp;°C (36&nbsp;°F) in core agricultural regions of the US, Europe, and China, and as much as 35&nbsp;°C (63&nbsp;°F) in Russia.<ref name="Robock">{{cite journal |last1=Robock |first1=Alan |last2=Oman|first2=Luke |last3=Stenchikov |first3=Georgiy L. |date=6 July 2007 |title=Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences |journal=[[Journal of Geophysical Research]] |volume=112 |issue=D13 |at=D13107 |doi=10.1029/2006JD008235 |doi-access=free |bibcode=2007JGRD..11213107R |url=http://climate.envsci.rutgers.edu/pdf/RobockNW2006JD008235.pdf |access-date=2007-12-05 |archive-url= https://web.archive.org/web/20110928005224/http://climate.envsci.rutgers.edu/pdf/RobockNW2006JD008235.pdf |archive-date=2011-09-28 |url-status=live  |issn=2156-2202}}</ref> This cooling would be produced due to a 99% reduction in the natural [[insolation|solar radiation]] reaching the surface of the planet in the first few years, gradually clearing over the course of several decades.<ref name=autogenerated3/>

Since the advent of photography that captured evidence of tall clouds,<ref>London 1906, San Francisco Fire and others.</ref> it has been known that firestorms could inject soot smoke and [[aerosol]]s 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 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 of the Earth|hemisphere]] that they burned in.<ref name="Fire-Breathing Storm Systems">{{cite web |author=Finneran |first=Michael |date=2010-10-19 |title=Fire-Breathing Storm Systems |url=http://www.nasa.gov/topics/earth/features/pyrocb.html |url-status=live |archive-url=https://web.archive.org/web/20140824082109/http://www.nasa.gov/topics/earth/features/pyrocb.html |archive-date=24 August 2014 |publisher=NASA}}</ref><ref>{{cite journal |last1=Fromm |first1=M. |last2=Tupper |first2=A. |last3=Rosenfeld |first3=D. |last4=Servranckx |first4=R. |last5=McRae |first5=R. |title=Violent pyro-convective storm devastates Australia's capital and pollutes the stratosphere |doi=10.1029/2005GL025161 |journal=Geophysical Research Letters |volume=33 |issue=5 |pages=L05815 |year=2006 |bibcode=2006GeoRL..33.5815F|s2cid=128709657 |doi-access=free }}</ref><ref>{{cite web |url=http://earthobservatory.nasa.gov/Features/PyroClouds/|title=Russian Firestorm: Finding a Fire Cloud from Space|date=31 August 2010|website=earthobservatory.nasa.gov|access-date=12 February 2015|archive-url=https://web.archive.org/web/20150212163237/http://earthobservatory.nasa.gov/Features/PyroClouds/ |archive-date=12 February 2015|url-status=live}}</ref> This is somewhat analogous to the frequent [[Volcanic explosivity index#Classification|volcanic eruptions that inject sulfates into 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 extinction|optical properties]] of this smoke.<ref>{{cite web|title=NASA to study how pollution, storms and climate mix |url=https://www.sciencedaily.com/releases/2013/06/130606133058.htm|access-date=2018-02-28|archive-url= https://web.archive.org/web/20180612140237/https://www.sciencedaily.com/releases/2013/06/130606133058.htm |archive-date=2018-06-12|url-status=live}}</ref><ref>{{cite web|title=Wildfires Smoke Crosses the Atlantic |date=2 July 2013 |website=earthobservatory.nasa.gov |url=http://earthobservatory.nasa.gov/IOTD/view.php?id=81500|access-date=3 October 2014|archive-url=https://web.archive.org/web/20141006110758/http://earthobservatory.nasa.gov/IOTD/view.php?id=81500|archive-date=6 October 2014|url-status=live}}</ref><ref name="journals.ametsoc.org">{{cite journal |title=The untold story of pyrocumulonimbus, 2010 |doi=10.1175/2010BAMS3004.1 |volume=91 |issue=9 |journal=Bulletin of the American Meteorological Society |pages=1193–1209 |year=2010 |last1=Fromm |first1=Michael |bibcode=2010BAMS...91.1193F |doi-access=free}}</ref><ref>{{cite journal |last1=Jacob |first1=D. J. |display-authors=etal |year=2010 |title=The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results |journal=Atmos. Chem. Phys. |volume=10 |issue=11 |pages=5191–5212 |bibcode=2010ACP....10.5191J |doi=10.5194/acp-10-5191-2010 |doi-access=free}}</ref><ref>{{cite journal|title=Canadian and Siberian Boreal Fire Activity during ARCTAS Spring and Summer Phases |last1=Stocks |first1=B. J. |last2=Fromm |first2=M. D. |last3=Soja |first3=A. J. |last4=Servranckx |first4=R. |last5=Lindsey |first5=D. |last6=Hyer |first6=E. |date=December 2009|journal=AGU Fall Meeting Abstracts|volume=2009|at=A41E–01 |bibcode=2009AGUFM.A41E..01S}}</ref> Information regarding all of these properties is necessary to truly ascertain the length and severity of the cooling effect of firestorms, independent of the nuclear winter computer model projections.{{cn|date=January 2024}}

Currently, from satellite tracking data, it appears that stratospheric smoke aerosols dissipate in a time span under approximately two months.<ref name="journals.ametsoc.org" /> The existence of a [[Tipping point (climatology)|tipping point]] into a new stratospheric condition where the aerosols would not be removed within this time frame remains to be determined.<ref name="journals.ametsoc.org" />