Nuclear holocaust

== Effects of nuclear war ==
{{Pollution sidebar|War|image=[[File:Castle Bravo 007.jpg|frameless]]}} 
Historically, it has been difficult to estimate the total number of deaths resulting from a global nuclear exchange because scientists are continually discovering new effects of nuclear weapons, and also revising existing models.

Early reports considered direct effects from nuclear blast and radiation and indirect effects from economic, social, and political disruption. In a 1979 report for the U.S. Senate, the [[Office of Technology Assessment]] estimated casualties under different scenarios. For a full-scale [[countervalue]]/[[counterforce]] nuclear exchange between the U.S. and the Soviet Union, they predicted U.S. deaths from 35 to 77 percent (70 million to 160 million dead at the time), and Soviet deaths from 20 to 40 percent of the population.<ref name="Report1979">{{cite book|last1=Johns|first1=Lionel S|last2=Sharfman|first2=Peter|last3=Medalia|first3=Jonathan|last4=Vining|first4=Robert W|last5=Lewis|first5=Kevin|last6=Proctor|first6=Gloria|title=The Effects of Nuclear War|url=https://www.princeton.edu/~ota/disk3/1979/7906/7906.PDF|publisher=Library of Congress|access-date=13 February 2016|date=1979}}</ref>

Although this report was made when nuclear stockpiles were at much higher levels than they are today, it also was made before the risk of nuclear winter was first theorized in the early 1980s. Additionally, it did not consider other secondary effects, such as electromagnetic pulses (EMP), and the ramifications they would have on modern technology and industry.

=== Nuclear winter ===
{{Main|Nuclear winter}}
In the early 1980s, scientists began to consider the effects of smoke and soot arising from burning wood, plastics, and petroleum fuels in nuclear-devastated cities. It was speculated that the intense heat would carry these particulates to extremely high altitudes where they could drift for weeks and block out all but a fraction of the sun's light.<ref name="Britannica">{{cite web|title=Nuclear winter|url=https://www.britannica.com/topic/nuclear-winter|website=Encyclopædia Britannica|access-date=13 February 2016}}</ref> A landmark 1983 study by the so-called TTAPS team ([[Richard P. Turco]], [[Owen Toon]], Thomas P. Ackerman, [[James B. Pollack]] and [[Carl Sagan]]) was the first to model these effects and coined the term "nuclear winter."<ref>{{cite journal |title=Nuclear Winter: Global Consequences of Multiple Nuclear Explosions |journal=Science |volume=222 |issue=4630 |pages=1283–92 |date=23 December 1983 |pmid=17773320 |doi=10.1126/science.222.4630.1283|bibcode = 1983Sci...222.1283T |last1=Turco |first1=R. P. |last2=Toon |first2=O. B. |last3=Ackerman |first3=T. P. |last4=Pollack |first4=J. B. |last5=Sagan |first5=C. |s2cid=45515251 }}</ref>

More recent studies make use of modern global circulation models and far greater computer power than was available for the 1980s studies. A 2007 study examined the consequences of a global nuclear war involving moderate to large portions of the current global arsenal.<ref name="Robock2007">{{cite journal|last1=Robock|first1=Alan|last2=Oman|first2=Luke|last3=Stenchikov|first3=Georgiy L.|title=Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences|journal=Journal of Geophysical Research|date=2007|volume=112|issue=D13107|page=14|doi=10.1029/2006JD008235|url=http://climate.envsci.rutgers.edu/pdf/RobockNW2006JD008235.pdf|access-date=13 February 2016|bibcode=2007JGRD..11213107R|doi-access=free}}</ref> The study found cooling by about 12–20&nbsp;°C in much of the core farming regions of the US, Europe, Russia and China and as much as 35&nbsp;°C in parts of Russia for the first two summer growing seasons. The changes they found were also much longer-lasting than previously thought, because their new model better represented entry of soot aerosols in the upper stratosphere, where precipitation does not occur, and therefore clearance was on the order of 10 years.<ref name="ToonandRobock2010" /> In addition, they found that global cooling caused a weakening of the global hydrological cycle, reducing global [[Precipitation (meteorology)|precipitation]] by about 45%.

The authors did not discuss the implications for agriculture in depth, but noted that a 1986 study which assumed no food production for a year projected that "most of the people on the planet would run out of food and starve to death by then" and commented that their own results show that, "This period of no food production needs to be extended by many years, making the impacts of nuclear winter even worse than previously thought."<ref name="Robock2007" />

In contrast to the above investigations of global nuclear conflicts, studies have shown that even small-scale, regional nuclear conflicts 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 populated centres, 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.<ref name="ScienceDaily">[https://www.sciencedaily.com/releases/2006/12/061211090729.htm Regional Nuclear War Could Devastate Global Climate], Science Daily, December 11, 2006</ref><ref name="RobockRegional2007"/><ref name="ToonandRobock2010"/> The cooling would last for years, and according to the research, could be "catastrophic". Additionally, the analysis showed a 10% drop in average global precipitation, with the largest losses in the low latitudes due to failure of the monsoons.

Regional nuclear conflicts could also inflict significant damage to the ozone layer. A 2008 study found that a regional nuclear weapons exchange could create a near-global ozone hole, triggering human health problems and impacting agriculture for at least a decade.<ref name=Mills2008>{{cite journal |title=Massive global ozone loss predicted following regional nuclear conflict |journal=Proc. Natl. Acad. Sci. U.S.A. |date=2008 |pmid=18391218 |pmc=2291128 |doi=10.1073/pnas.0710058105 |last1=Mills |first1=M. J. |last2=Toon |first2=O. B. |last3=Turco |first3=R. P. |last4=Kinnison |first4=D. E. |last5=Garcia |first5=R. R. |volume=105 |issue=14 |pages=5307–12 |bibcode = 2008PNAS..105.5307M |doi-access=free }}[http://acd.ucar.edu/~mmills/pdf/2008MillsPNAS_MassiveOzoneLoss.pdf as PDF] {{webarchive|url=https://web.archive.org/web/20160304100404/http://acd.ucar.edu/~mmills/pdf/2008MillsPNAS_MassiveOzoneLoss.pdf |date=2016-03-04 }}</ref> This effect on the ozone would result from heat absorption by soot in the upper stratosphere, which would modify wind currents and draw in ozone-destroying nitrogen oxides. These high temperatures and nitrogen oxides would reduce ozone to the same dangerous levels that are experienced below the ozone hole above Antarctica every spring.<ref name="ToonandRobock2010"/>

=== Nuclear famine ===
{{Main|Nuclear famine}}
It is difficult to estimate the number of casualties that would result from nuclear winter, but it is likely that the primary effect would be global famine (known as Nuclear Famine), wherein mass starvation occurs due to disrupted agricultural production and distribution.<ref>Harwell, M., and C. Harwell. (1986). "Nuclear Famine: The Indirect Effects of Nuclear War", pp. 117–135 in Solomon, F. and R. Marston (Eds.). ''The Medical Implications of Nuclear War''. Washington, D.C.: National Academy Press. {{ISBN|0309036925}}.</ref> In 2013 and 2022 reports, the [[International Physicians for the Prevention of Nuclear War]] (IPPNW) voiced concerns that more than two billion people, about a third of the world's population, would be at risk of starvation in the event of a regional nuclear exchange between India and Pakistan, or by the use of even a small proportion of nuclear arms held by America and Russia.<ref name="IPPNWreport2013">{{cite web|last1=Helfand|first1=Ira|title=Nuclear Famine: Two Billion Prople at Risk?|url=https://www.ippnw.org/wp-content/uploads/2020/07/2013-Nuclear-Famine.pdf|website=IPPNW|access-date=30 December 2022}}</ref><ref name="IPPNWreport2022">{{cite web|last1=Bivens|first1=Matt|title=Nuclear Famine: Even a "limited" nuclear war would cause abrupt climate disruption and global starvation|url=https://www.ippnw.org/wp-content/uploads/2022/09/ENGLISH-Nuclear-Famine-Report-Final-bleed-marks.pdf|website=IPPNW|access-date=30 December 2022}}</ref> Several independent studies{{Citation needed|date=December 2020}} show corroborated conclusions that agricultural outputs would be significantly reduced for years by climatic changes driven by nuclear wars. Reduction of food supply would be further exacerbated by rising [[food prices]], affecting hundreds of millions of vulnerable people, especially in the poorest nations of the world.

According to a peer-reviewed study published in the journal ''[[Nature Food]]'' in August 2022,<ref name="NatureFood2022"></ref> a full-scale nuclear war between the U.S. and Russia might kill 360 million people directly and more than 5 billion people might die as a consequence from [[starvation]] due to soot created by firestorms after nuclear bombing. More than 2 billion people were projected to die as a consequence from a smaller-scale nuclear war between India and Pakistan. In the event of a nuclear war between Russia and the United States, 99% of the people in the United States, Russia, Europe, and China would die.<ref>{{cite magazine |title=Here's How Bad a Nuclear War Would Actually Be |url=https://time.com/6290977/nuclear-war-impact-essay/ |magazine=Time |date=29 June 2023}}</ref>

=== Electromagnetic pulse ===
{{See also|Nuclear electromagnetic pulse|High-altitude nuclear explosion}}

An [[electromagnetic pulse]] (EMP) is a burst of electromagnetic radiation. Nuclear explosions create a pulse of electromagnetic radiation called a nuclear EMP or NEMP. Such EMP interference is known to be generally disruptive or damaging to electronic equipment.<ref name="science">Broad, William J. "Nuclear Pulse (I): Awakening to the Chaos Factor", ''Science''. 29 May 1981 212: 1009–1012</ref>

By disabling electronics and their functioning, an EMP would disable hospitals, water treatment facilities, food storage facilities, and all electronic forms of communication, and thereby threaten key aspects of the modern human condition.{{citation needed|date=November 2016}} Certain EMP attacks could lead to a large loss of power for months or years.<ref name="EMP report">{{cite web|title=Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack|url=http://commdocs.house.gov/committees/security/has204000.000/has204000_0.HTM|access-date=16 January 2016}}</ref> Currently, failures of the power grid are dealt with using support from the outside. In the event of an EMP attack, such support would not exist and all damaged components, devices, and electronics would need to be completely replaced.

In 2013, the US House of Representatives considered the "Secure High-voltage Infrastructure for Electricity from Lethal Damage Act" that would provide surge protection for some 300 large transformers around the country.<ref>{{cite web |last1=McCormack|first1=John |title=Lights out: House plan would protect nation's electricity from solar flare, nuclear bomb |date=2013-06-17 |url=http://www.washingtonexaminer.com/lights-out-house-plan-would-protect-nations-electricity-from-solar-flare-nuclear-bomb/article/2532038 |website=[[Washington Examiner]] |access-date=2016-01-16}}</ref> The problem of protecting civilian infrastructure from electromagnetic pulse has also been intensively studied throughout the European Union, and in particular by the United Kingdom.<ref>House of Commons
Defence Committee, [https://publications.parliament.uk/pa/cm201012/cmselect/cmdfence/1552/1552.pdf "Developing Threats: Electro-Magnetic Pulses (EMP)"]. Tenth Report of Session 2010–12.</ref> While precautions have been taken, James Woolsey and the EMP Commission suggested that an EMP is the most significant threat to the U.S.<ref name="EMP report"/><ref>{{cite news |last1=Woosley|first1=R. James |last2=Pry|first2=Peter Vincent |title=The Growing Threat From an EMP Attack |date=2014-08-12 |url=https://www.wsj.com/articles/james-woolsey-and-peter-vincent-pry-the-growing-threat-from-an-emp-attack-1407885281 |newspaper=[[Wall Street Journal]] |access-date=2016-01-16 |url-access=subscription }}</ref>

The risk of an EMP, either through solar or atmospheric activity or enemy attack, while not dismissed, was suggested to be overblown by the news media in a commentary in ''[[Physics Today]]''.<ref name="PT2016">{{cite journal |first1=Steven T. |last1=Corneliussen |title=Conservative media sustain alarm about a possible electromagnetic-pulse catastrophe |date=2016-06-23 |doi=10.1063/PT.5.8178 |journal=[[Physics Today]] }}</ref> Instead, the weapons from rogue states were still too small and uncoordinated to cause a massive EMP, underground infrastructure is sufficiently protected, and there will be enough warning time from continuous solar observatories like [[Solar and Heliospheric Observatory|SOHO]] to protect surface transformers should a devastating solar storm be detected.<ref name="PT2016"/>

=== Nuclear fallout ===
{{Main|Nuclear fallout}}

Nuclear fallout is the residual radioactive dust and ash propelled into the upper atmosphere following a nuclear explosion.<ref>{{cite web|url=http://www.atomicarchive.com/Effects/effects17.shtml|title=Radioactive Fallout {{!}} Effects of Nuclear Weapons {{!}} atomicarchive.com|website=www.atomicarchive.com|access-date=2016-12-31}}</ref> Fallout is usually limited to the immediate area, and can only spread for hundreds of kilometers from the explosion site if the explosion is high enough in the atmosphere. Fallout may get [[Entrainment (meteorology)|entrained]] with the products of a [[pyrocumulus]] cloud and fall as black rain<ref>{{cite web|url=http://atomicbombmuseum.org/3_radioactivity.shtml|title=AtomicBombMuseum.org – Destructive Effects|website=atomicbombmuseum.org|access-date=2016-12-31}}</ref> (rain darkened by soot and other particulates).

This radioactive dust, usually consisting of [[fission product]]s mixed with bystanding atoms that are [[neutron activation|neutron activated by exposure]], is a highly dangerous kind of [[radioactive contamination]]. The main radiation hazard from fallout is due to short-lived radionuclides external to the body.<ref name="AtomicArchive">{{cite web|title=Radioactive Fallout|url=http://www.atomicarchive.com/Effects/effects17.shtml|website=Atomic Archive|access-date=23 January 2016}}</ref> While most of the particles carried by nuclear fallout decay rapidly, some radioactive particles will have half-lives of seconds to a few months. Some radioactive isotopes, like [[strontium-90]] and [[caesium-137]], are very long-lived and will create radioactive hot spots for up to 5 years after the initial explosion.<ref name="AtomicArchive"/> Fallout and black rain may contaminate waterways, agriculture, and soil. Contact with radioactive materials can lead to radiation poisoning through external exposure or accidental consumption. In acute doses over a short amount of time radiation will lead to prodromal syndrome, bone marrow death, central nervous system death and gastrointestinal death.<ref name = "Coggle & Lindop">Coggle, J.E., Lindop, Patricia J. "Medical Consequences of Radiation Following a Global Nuclear War." The Aftermath (1983): 60–71.</ref> Over longer periods of exposure to radiation, cancer becomes the main health risk. Long-term radiation exposure can also lead to in utero effects on human development and transgenerational genetic damage.<ref name = "Coggle & Lindop"/><ref>{{cite web|url=http://www.rerf.jp/radefx/genetics_e/birthdef.html|title=公益財団法人 放射線影響研究所 RERF|website=www.rerf.jp|access-date=16 November 2018}}</ref>