6
$\begingroup$

I'm trying to figure out how a nuclear war in the north hemisphere would affect the south (specially South America, where my story is set).

I read about the nuclear fallout and nuclear winter consequences, but all I saw is that the southern hemisphere wouldn't suffer that much apart from minimal climate changes (and only for a few months - correct me if I'm wrong).

What I need is a event that would trigger nuclear winter in South America, but not killing people in mass in that area (in a practical way, anything can be devastated, except South America). Like I said, I was hoping that a nuclear war in the northern part of the world would give me this effect, but my research concluded that the damage would be medium to minimal, and just for a few months. Of course a full-scale nuclear war would lead to that, but it would mass-murder the entire world.

How a nuclear detonation/war could lead to winter in South America? How "big" or "exceptional" this event would need to be?

Thanks!

$\endgroup$
  • $\begingroup$ Can't have nuclear winter without mass explosions and killing, sorry. $\endgroup$ – Mołot Oct 3 '16 at 18:09
  • 1
    $\begingroup$ Well, I didn't explained well. I just don't need mass murder in South America. I'll edit the question. $\endgroup$ – Radec Oct 3 '16 at 18:10
5
$\begingroup$

I would refer you to the 1957 post-apocalyptic novel On the Beach and its 1959 film version.

The novel details the experiences of a mixed group of people in Melbourne as they await the arrival of deadly radiation spreading towards them from the Northern Hemisphere following a nuclear war a year previously.

You have to consider, that we are an interconnected planet. Even isolated atomic accidents can reach other hemispheres. It is not only the wind, but consider propagation through water currents, rivers. Fauna that survives would probably migrate carrying the poison with them.

I do not know how to calculate the spread rate, nor the maximum damage to the north hemisphere to prevent damage to the south, but if your scenario depicts destroying the north by anything other than accident, you can expect there would also be plans to destroy potential supplies from the enemy, i.e., the south.

In any case, I would be interested in reading your story.

Good luck!

UPDATE: For a more scientific or precise description of the nuclear winter process and requirements, I would suggest the following article Nuclear winter.

$\endgroup$
  • 1
    $\begingroup$ Nice answer. In this case, South America would not be targeted - because countries involved in the war would blow up each other. I'm only interested in the effects a nuclear war in the north would cause to South America, and your answer adds so much to the subject. Thank you! $\endgroup$ – Radec Oct 3 '16 at 18:35
  • 1
    $\begingroup$ @Nimrod, thank you. I would definitely be interested in the fictional story that you are working on. However, let me suggest you add other reasons for South America not being targeted, e.g., a combination of failed mechanism or guidance systems, human factors (disobeying orders), destruction of secondary launch pads, etc. It would be interesting to read about your take on immigrants (survivors) from the north arriving on the south. $\endgroup$ – David Oct 3 '16 at 18:44
  • 6
    $\begingroup$ "On the Beach" is a novel, not a scientific treatise. Its depiction of the effects of radiation, and nuclear weapons, is less than accurate. $\endgroup$ – jamesqf Oct 3 '16 at 19:15
  • 1
    $\begingroup$ This answer doesn't go into any processes or specifics which the question asks for. I would like to see an answer which actually explains how large a nuclear event would have to be to create a global nuclear winter. $\endgroup$ – inappropriateCode Oct 4 '16 at 13:58
  • 1
    $\begingroup$ @inappropriateCode you are right. Will edit answer if I can to reflect your concern. $\endgroup$ – David Oct 4 '16 at 14:25
2
$\begingroup$

If you think the nuclear winter is not enough to have a heavy impact on the south, why not have one nuke hit Yellowstone and trigger the volcano? Where a nuclear or a volcanic winter might be northern hemisphere only a combination of both should/ or at least could be big enough to cool down the south, too.

One important thing to remember is that even a "slight" cooling of only 1-2°C can disrupt crops not meant for this new climate. And in addition to that the weather could change if the temperatures drop.So not only do the crops get too little warmth, they get the wrong amount of water, too. Same for cattle, the change in temperature can cause them to become ill.

$\endgroup$
2
$\begingroup$

take a look here : http://science.howstuffworks.com/nuclear-winter2.htm

The article details six levels of nuclear winter: Minimal, Marginal, Nominal, Substantial, Severe and Extreme (in the final case everybody and everything dies). For most of these scenarios; the conclusion from their analysis is based on this fact:

Everything below the equator would remain mostly unaffected, given the hemispheric separation of air currents and the fact that most nuclear targets exist in the Northern Hemisphere.

The worst level for which humanity will likely survive is this:

Substantial nuclear winter: This scenario, following full-scale nuclear war, involves catastrophic consequences for the Northern Hemisphere: freezing temperatures, widespread fallout, pollution, ozone depletion and disrupted precipitation. Imagine a deeply overcast day -- now imagine those conditions persisting for years. Green plants would barely receive enough sunlight for photosynthesis. Crops would fail, billions of humans would die, species would go extinct and while humanity would likely survive, civilization as we know it might not. Damage to the Southern Hemisphere would depend on the number of detonations below the equator.

In other words, the most plausible outcome for full-scale nuclear war is a hellscape in the Northern Hemisphere (where nearly all the major cities are) and a lightly damaged Southern Hemisphere (South America, Australia, the southern third of Africa, New Zealand, many islands).

If the Southern Hemisphere does suffer Nuclear Winter, it would be one of the earlier levels: Marginal would be plausible. You can look at those to see how much damage would likely occur in South America (or the southern hemisphere in general). Perhaps any big cities or major population centers would be bombed in a full scale war (thousands of nuclear bombs).

I live in Argentina and I think all here in South America would have to accommodate many people, basically anybody that survived in the Northern Hemisphere. The current population is around 420 million, perhaps tens of millions more would be refugees. This could trigger revolutions and new political orders and alignments, which may or may not be good.

$\endgroup$
  • 3
    $\begingroup$ please flesh out your answer some more. As it is now it's barely a comment and a link, and as such it can be deleted. $\endgroup$ – L.Dutch Aug 9 '17 at 14:52
  • $\begingroup$ I don't know much about what would be an answer in this stack, but your's is very helpful. If they delete it, know that I really liked it. Thanks! $\endgroup$ – Radec Aug 17 '17 at 18:02
1
$\begingroup$

If a nuclear winter would hit the northern hemisphere only, then the survivors of the war would all head south. Lets say 50-100million north americans all walk into South America. That kind of migration will lead to mass riots, mass starvation and a complete breakdown of society as we know it. I think I'd prefer the winter..

$\endgroup$
-2
$\begingroup$

http://www.uow.edu.au/~bmartin/pubs/82cab/

Talks about the impact of nuclear war on Australia

$\endgroup$
  • 4
    $\begingroup$ Hi CaptainBarnacles, welcome to the Worldbuilding StackExchange. Links are always welcome in answers, but you should explain the essentials of the linked page in your answer, so that if in future the link breaks your answer can still be useful to others. For example, what exactly does the page you linked say about the effects of nuclear war on Australia, and how does that apply to the specifics of the question being asked? Hope this feedback helps, look forward to seeing you around the site. $\endgroup$ – realityChemist Feb 27 '17 at 3:20
  • 1
    $\begingroup$ Damn, but this link is actually quite good... $\endgroup$ – Shadow1024 Jun 29 '17 at 13:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.