In year 2020, the world leaders started a third World War, nuking military installations, government stations, and population centers, which resulted in a nuclear holocaust, wiping out roughly 50% of humans, with the rest taking shelter in bunkers. Much like Chernobyl and Pripyat, beasts and plants florish despite the radiation, becoming mutants from the radiation affecting their physiology and appearance. But so have humans. 20% of the original human population live as such, while the 30% are in nuclear shelter. When the people come out of their bunkers years later, (let's say 10 years?) after the radiation dies down enough, mutant humans will have already had a society going. How many mutant humans would be on earth at this point? The surviving humans are irregularly spread over the world, the mutant ones living like they're in the mid-late 1800s due to lack of electricity and power.

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    $\begingroup$ Note that most of those "mutants" should actually be called "people with cancer" by the normals. Some will survive, some won't. $\endgroup$
    – user535733
    Dec 29, 2021 at 5:06
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    $\begingroup$ Folks-in-bunkers-for-a-decade have been discussed before. Most emergency bunkers lack food, clean water, and air for a decade, also fuel for the water pumps and air scrubbers and lights, and also lack places to dispose of a decade of sewage, trash, and corpses. It's a vast tonnage and volume. $\endgroup$
    – user535733
    Dec 29, 2021 at 5:10
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    $\begingroup$ Radionuclides from weapons tend to be short-lived. In Nagasaki, for example, most (not all) of the city was safe to rebuild after a few weeks and a few rains. Whether or not the devastated society is capable of rebuilding is, of course, a different question. $\endgroup$
    – user535733
    Dec 29, 2021 at 5:11
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    $\begingroup$ I'm not sure if the mutations around Pripyat are part of your script, but they aren't huge changes in the creatures nor required to live there. Life flourishes because there's no humans meddling. In addition they tend to have good enough health to get healthy offspring before the radiation gets to them. Most even die before radiation can do something. The same will be true for the humans. Unless they were close to big sources of radiation they are most likely alive and relatively healthy after 10 years. Any mutations are most likely invisible or at most a cancerous growth. $\endgroup$
    – Trioxidane
    Dec 29, 2021 at 11:16
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    $\begingroup$ "let's say 10 years?" your term of 10 years is very short. Mutations are deadly in adults, it can result in cancer and fertility loss. After 10 years, there will be some kids (under 10) born with mutations (different properties), but these kids are not adult yet, they won't have children, or a "society" of any kind. They are survivors in the company of their non-mutant mother. $\endgroup$
    – Goodies
    Dec 29, 2021 at 12:28

2 Answers 2


First, let me point out that there are no shelters for such a large part of the population, let alone with years of endurance. The industrialized world had some fallout shelters, with filters and food for a few weeks, and even fewer actual bunkers to survive a blast. The shelters were also distributed very unevenly. Switzerland used to have many, relative to the population. Many NATO and WP countries stopped building them, and there was a generation for shifts in population patterns. No shelters in the new suburbs!

Second, most mutations cause cancer at some point in the lifetime of an individual, but there are species which might not live enough for that to matter. That's why plants and animals seem to thrive in nuclear disaster zones. There might be a little bit of natural selection for mutations which make the individual more resistant to cancer, but not mutations in the Hollywood or superhero sense.

The nuclear exchange will probably kill many people. Even more will die from the ecological consequences (nuclear winter) and the overall disruption of society and supply chains. There is the proverb that any city is just three square meals from anarchy (the authorship seems unclear, however).

So you might kill somewhere around 10% of the world population in the initial exchange, concentrated in the industrialized parts of the West and Russia. Then a large number will die because trucks don't deliver food to the cities and fertilizer to the farms, and because there are no factories to make fertilizer. This will be global.

The survivors might then find that their latest high-tech GM crops are not suitable for re-seeding.

All this is very hard to estimate, but you would be justified in having anywhere from 20% to 95% of mankind killed in your scenario.


According to this page, world population in 1850 amounted to 1.2 billion people.

Considering that

  • the majority of the world is coming out of a war, with major settlements reduced to wasteland,
  • the better places to survive are those with a sparse population and plenty of resources in terms of water and cultivable soil
  • mechanized agriculture is nowhere existing,

I guess a reasonable ballpark figure would be somewhere in the range 0.6 to 1.2 billion people.


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