Nuclear holocaust

==Origins and analysis of extinction hypotheses==
As a result of the extensive [[nuclear fallout]] of the 1954 [[Castle Bravo]] nuclear detonation, author [[Nevil Shute]] wrote the popular novel ''[[On the Beach (novel)|On the Beach]]'', released in 1957. In this novel, so much fallout is generated in a nuclear war that all human life is extinguished. However, the premise that all of humanity would die following a nuclear war and only the "cockroaches would survive" is critically dealt with in the 1988 book ''[[Philip J. Dolan#Unclassified publications|Would the Insects Inherit the Earth and Other Subjects of Concern to Those Who Worry About Nuclear War]]'', by nuclear weapons expert [[Philip J. Dolan]].

In 1982, [[nuclear disarmament]] activist [[Jonathan Schell]] published ''[[The Fate of the Earth]]'', which is regarded by many to be the first carefully argued presentation that concluded that extinction is a significant possibility from nuclear war. However, the assumptions made in this book have been thoroughly analyzed and determined to be "quite dubious".<ref name="The fate of extinction arguments">{{cite web |url=http://www.bmartin.cc/pubs/83fea.html |title=The fate of extinction arguments|date=March 1983|author=Martin, Brian|publisher=Department of Mathematics, Faculty of Science, Australian National University }}</ref> The impetus for Schell's work, according to physicist Brian Martin, was:

<blockquote> The implicit premise [...] that if people are not taking action on the issue, they must not perceive it as threatening enough. Perhaps if the thought of 500 million people dying in a nuclear war is not enough to stimulate action, then the thought of extinction will. Indeed, Schell explicitly advocates use of the fear of extinction as the basis for inspiring the "complete rearrangement of world politics" (p. 221)<ref name="The fate of extinction arguments" /></blockquote>

The belief in "overkill" is also commonly encountered, with an example being the following statement made by nuclear disarmament activist [[Philip Noel-Baker]] in 1971: "Both the US and the Soviet Union now possess nuclear stockpiles large enough to exterminate mankind three or four – some say ten – times over". Brian Martin suggested that the origin of this belief was from "crude linear extrapolations" of the bombing of Hiroshima. He said that if the bomb dropped on Hiroshima had been 1,000 times as powerful, it could not have killed 1,000 times as many people.<ref name="ReferenceB"/> Similarly, it is common to see stated that the combined explosive energy released in the entirety of [[World War II]] was about 3 megatons, while a nuclear war with warhead stockpiles at Cold War highs would release 6000 WWII's of explosive energy.<ref>{{cite journal|author=Willens, Harold|author-link=Harold Willens|url=http://c-g-i.info/images/nuclear-weapons-chart.jpg |title=The Trimtab factor, 1984 |year=1990 |journal=Alternatives |volume=16|issue=4}}</ref> An estimate for the necessary amount of fallout to begin to have the potential of causing human extinction is regarded by physicist and disarmament activist [[Joseph Rotblat]] to be 10 to 100 times the megatonnage in nuclear arsenals as they stood in 1976; however, with the world megatonnage decreasing since the Cold War ended this possibility remains hypothetical.<ref name="ReferenceB"/>
[[File:NuclearTestUS.gif|thumb|300px|The massive use and deployment of nuclear weapons are commonly theorized to yield enough global destructive potential to render large parts of the Earth uninhabitable.]]
According to the 1980 [[United Nations]] report ''General and Complete Disarmament: Comprehensive Study on Nuclear Weapons: Report of the Secretary-General'', it was estimated that there were a total of about 40,000 [[Historical nuclear weapons stockpiles and nuclear tests by country|nuclear warheads in existence]] at that time, with a potential combined explosive yield of approximately 13,000 [[TNT equivalent|megatons]].

By comparison – in the [[timeline of volcanism on Earth]] – the [[1815 eruption of Mount Tambora|1815 eruption]] of [[Mount Tambora]] exploded with a force of roughly 30,000 megatons,<ref>{{Cite journal|date=1986-01-01|title=The petrology of Tambora volcano, Indonesia: A model for the 1815 eruption|url=https://www.sciencedirect.com/science/article/abs/pii/037702738690079X|journal=Journal of Volcanology and Geothermal Research|language=en|volume=27|issue=1–2|pages=1–41|doi=10.1016/0377-0273(86)90079-X|issn=0377-0273|last1=Foden|first1=J.|bibcode=1986JVGR...27....1F}}</ref> and ejected {{convert|160|km3|cumi|abbr=on}} of mostly rock and [[tephra]],<ref name="Stothers1984">
{{cite journal | last = Stothers | first = Richard B. | journal = [[Science (journal)|Science]] | title = The Great Tambora Eruption in 1815 and Its Aftermath | volume = 224 | issue = 4654 | date = 1984 | pages = 1191–1198 | doi = 10.1126/science.224.4654.1191 | pmid = 17819476
|bibcode = 1984Sci...224.1191S | s2cid = 23649251 }}
</ref> which included 120 million [[tonne]]s of sulfur dioxide as [[Mount Tambora#Global effects|an upper estimate]], turning 1816 into the "[[Year Without a Summer|year without a summer]]" due to the levels of [[global dimming]] [[sulfate]] aerosols and ash expelled.<ref name="Oppenheimer2003">
{{cite journal | last = Oppenheimer | first = Clive | title = Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815 | journal = Progress in Physical Geography | volume = 27 | issue = 2 | date = 2003 | pages = 230–259 | doi = 10.1191/0309133303pp379ra
| bibcode = 2003PrPG...27..230O | s2cid = 131663534 }}
</ref> The larger [[Lake Toba#Major eruption|Mount Toba eruption]], which occurred approximately 74,000 years ago, produced an estimated {{convert|2800|km3|abbr=on}} of tephra<ref name=USGS>{{cite web |url= http://hvo.wr.usgs.gov/volcanowatch/2005/05_04_28.html |title=Supersized eruptions are all the rage! |date=April 28, 2005 |publisher=[[United States Geological Survey|USGS]]}}</ref> and {{convert|6000|e6t|ST}} of sulfur dioxide,<ref name=robock2009>{{cite journal
 | author1=Robock, A.|author2=C.M. Ammann|author3=L. Oman|author4=D. Shindell|author5=S. Levis|author6=G. Stenchikov
 | title=Did the Toba volcanic eruption of ~74k BP produce widespread glaciation?
 | journal=[[Journal of Geophysical Research]] | date=2009 | volume=114 |issue=D10| pages= D10107
 | doi=10.1029/2008JD011652
| bibcode=2009JGRD..11410107R
| doi-access=free}}</ref><ref>{{cite journal 
 | last1 = Huang | first1 = C.Y.
 | last2 = Zhao | first2 = M.X.
 | last3 = Wang | first3 = C.C.
 | last4 = Wei | first4 = G.J.
 | title = Cooling of the South China Sea by the Toba Eruption and correlation with other climate proxies ~71,000 years ago
 | journal = Geophysical Research Letters | date = 2001 | volume = 28 | issue = 20 | pages = 3915–3918
 | doi = 10.1029/2000GL006113 | bibcode=2001GeoRL..28.3915H
| doi-access = free }}</ref> with a possible explosion force of 20,000,000 megatons (Mt) of TNT, forming [[Lake Toba]] and reducing the human population to mere tens of thousands. The [[Chicxulub impact]], connected with the [[extinction of the dinosaurs]], corresponds to at least 70,000,000&nbsp;Mt of energy, which is roughly 7000 times the combined maximum arsenal of the US and Soviet Union.

Comparisons with [[supervolcanos]] are more misleading than helpful due to the different [[aerosol]]s released, the likely [[air burst]] fuzing height of nuclear weapons and the globally scattered location of these potential nuclear detonations all being in contrast to the singular and subterranean nature of a supervolcanic eruption.<ref name="ReferenceA">[[Lynn Margulis|Margulis, Lynn]] (1999). ''Symbiotic Planet: A New Look At Evolution''. Houston: Basic Book.</ref> Moreover, assuming the entire world stockpile of weapons were grouped together, it would be difficult due to the [[nuclear fratricide]] effect to ensure the individual weapons would detonate all at once. Nonetheless, many people believe that a full-scale nuclear war would result, through the nuclear winter effect, in the [[human extinction|extinction of the human species]], though not all analysts agree on the assumptions put into these nuclear winter models.<ref name="bmartin.cc"/>