Editing Nuclear winter (section)

== Consequences ==
[[File:Global temperature changes after nuclear winter.jpg|thumbnail|left|upright=1.8|Diagram obtained by the [[CIA]] from the ''International Seminar on Nuclear War'' in Italy 1984. It depicts the findings of Soviet 3-D computer model research on nuclear winter from 1983, and although containing similar errors as earlier Western models, it was the first 3-D model of nuclear winter. (The three dimensions in the model are longitude, latitude and altitude.){{sfn|Goure|1986|pp=2–7}} The diagram shows the models predictions of global temperature changes after a global nuclear exchange. The top image shows effects after 40 days, the bottom after 243 days. A co-author was nuclear winter modelling pioneer [[Vladimir Alexandrov]].{{sfn|Interagency Intelligence Assessment|1984|pp=10–11}}<ref name="Alexandrov, V. V 1983">Alexandrov, Vladimir V. and Stenchikov, G. I. (1983): "On the modeling of the climatic consequences of the nuclear war" ''The Proceeding of Appl. Mathematics'', The Computing Center of the USSR Academy of Sciences, Moscow, USSR.</ref> Alexandrov disappeared in 1985. As of 2016, there remains ongoing speculation by friend, [[Andrew Revkin]], of foul play relating to his work.<ref>{{cite web |title=Scientific thaw during the cold war |url=http://www.pulitzercenter.org/reporting/scientific-thaw-during-cold-war |website=Pulitzer Center |archive-url=https://web.archive.org/web/20161202101346/http://pulitzercenter.org/reporting/scientific-thaw-during-cold-war |archive-date=2016-12-02 |url-status=live |date=May 2, 2016 |author=Kit R. Roane}}</ref>]]

=== Climatic effects ===
A study presented at the annual meeting of the [[American Geophysical Union]] in December 2006 found that even 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 [[Atomic bombings of Hiroshima and Nagasaki|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 the grain-growing regions. The cooling would last for years, and, according to the research, could be "catastrophic",<ref name=autogenerated3/><ref>{{cite web |title=Regional Nuclear War Could Devastate Global Climate |url=https://www.sciencedaily.com/releases/2006/12/061211090729.htm |archive-url= https://web.archive.org/web/20180516230926/https://www.sciencedaily.com/releases/2006/12/061211090729.htm |archive-date=2018-05-16 |url-status=live |work=Science Daily |date=December 11, 2006}}</ref> disrupting agricultural production and food gathering in particular in higher latitude countries.<ref>{{Cite web |date=2022-03-30 |title=How would a nuclear winter impact food production? |url=https://www.sciencedaily.com/releases/2022/03/220330164525.htm |access-date=2022-04-04 |website=ScienceDaily |language=en}}</ref><ref name=Xia2022/>

=== Ozone depletion ===
Nuclear detonations produce large amounts of [[NOx|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 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.<ref>{{cite journal |last1=Kao |first1=Chih-Yue Jim |last2=Glatzmaier |first2=Gary A. |last3=Malone |first3=Robert C. |last4=Turco |first4=Richard P. |title=Global three-dimensional simulations of ozone depletion under postwar conditions |journal=Journal of Geophysical Research |date=1990 |volume=95 |issue=D13 |page=22495 |doi=10.1029/JD095iD13p22495|bibcode=1990JGR....9522495K }}</ref>

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 a decade.<ref>{{cite Q|Q24657259}}</ref> 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 {{convert|50|mi|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.<ref>{{Cite journal |last1=Bardeen |first1=Charles G. |last2=Kinnison |first2=Douglas E. |last3=Toon |first3=Owen B. |last4=Mills |first4=Michael J. |last5=Vitt |first5=Francis |last6=Xia |first6=Lili |last7=Jägermeyr |first7=Jonas |last8=Lovenduski |first8=Nicole S. |last9=Scherrer |first9=Kim J. N. |last10=Clyne |first10=Margot |last11=Robock |first11=Alan |date=2021-09-27 |title=Extreme Ozone Loss Following Nuclear War Results in Enhanced Surface Ultraviolet Radiation |url=https://onlinelibrary.wiley.com/doi/10.1029/2021JD035079 |journal=Journal of Geophysical Research: Atmospheres |language=en |volume=126 |issue=18 |doi=10.1029/2021JD035079 |bibcode=2021JGRD..12635079B |s2cid=238213347 |issn=2169-897X}}</ref>

=== Nuclear summer ===
A "nuclear summer" is a hypothesized scenario in which, after a nuclear winter caused by [[aerosol]]s inserted into the atmosphere that would prevent sunlight from reaching lower levels or the surface,<ref name="New Scientist">{{cite journal|journal=[[New Scientist]]|date=February 26, 1987|title=Researchers Blow Hot and Cold Over Armageddon|page=28}}</ref> has abated, a [[greenhouse effect]] then occurs due to carbon dioxide released by combustion and [[methane]] released from the [[marsh gas|decay of the organic matter]] such as corpses that froze during the nuclear winter.<ref name="New Scientist"/><ref name="Irregular Warfare">{{cite web |author=Gates |first=John M. |title=The U.S. Army and Irregular Warfare, Chapter Eleven The Continuing Problem of Conceptual Confusion |url=http://www3.wooster.edu/history/jgates/book-ch11.html |archive-url=https://web.archive.org/web/20110814051805/http://www3.wooster.edu/history/jgates/book-ch11.html |archive-date=2011-08-14 |access-date=2011-11-27}}</ref>

Another more sequential hypothetical scenario, following 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<sub>2</sub> and other greenhouse gases from burning, followed by more released from the decay of dead organic matter. The detonations would also insert [[nitrogen oxide]]s into the stratosphere that would then deplete the [[ozone layer]] around the Earth.<ref name="New Scientist"/>

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.<ref name="Irregular Warfare"/>