can we really end civilization with nukes?

April 20, 2010

One of the truisms we’ve taken for granted since the height of the Cold War was that if all the nuclear weapons in the world were detonated at once, civilization would collapse. How could it not? The energy these warheads produce can wipe out an average city in less than a minute and there are thousands of them laying around the world at any given time, with just over 90% of the planet’s nuclear arsenal located in the U.S. and Russia. But I recently stumbled across an interesting proposition from visual journalist David McCandless, who decided to crunch the numbers and found that the worlds’ nuclear arsenal is less than 1% of what’s required to reduce every populated area in the world to radioactive rubble. Pretty assuring finding, isn’t it? Unfortunately, there are a few very serious issues with the assumptions McCandless made in his visualization, issues that could very easily bring back the notion of a nuclear apocalypse caused by generals with awfully itchy trigger fingers.

Before we dive into the technical details, let’s review how the finding in question was reached. We identify the surface area of the world populated by humans and the destructive radius of the biggest and most powerful nuclear weapons in our stockpiles. Then, we divide the former by the latter and compare the number to all the nuclear weapons officially accounted for or estimated and find that it’s just 0.83% of the result. But there’s a bit of a problem with taking the 20 megaton warheads as a standard nuke. In reality, the average nuclear bomb is far less powerful and is probably closer to about 1 megaton* in yield. That might seem like good news at first, but we need to consider the area affected not just by the blast itself, but by the lethal radioactive fallout, up to a staggering 90 miles away over a seven day period. The gives us a total affected area of some 65,869 km², a lot more than the 14.9 km² used by McCandless. Divide the total inhabited area by the lethal reach of a fallout plume and you end up just shy of 283 bombs. Granted, we’re using an area more than 4,390 times larger for our result, but considering how much damage nuclear warheads cause with their fallout, we have to account for the total affected area, not just the zone of immediate destruction from the blast’s hypocenter.

So when we take radiation into account, it seems that the given total of 10,225 bombs is about 36 times more than we will ever need to destroy or poison every square centimeter of inhabited land on Earth. Even the least affected territory in this scenario would send Geiger counters to 900 rem, more than enough to trigger a slow and very painful death about two weeks after exposure. Without very quick and very intensive medical care, an emergency bone marrow transplant, and extensive work on repairing the severe damage to intestinal tissues, the poisoned person doesn’t even have a glimmer of a chance of surviving past 14 days after exposure. Areas closer to the blast would almost instantly deliver a far more than lethal dose of radiation to survivors. Only the toughest bacteria and insects would survive past a few months in these conditions. But of course, since there are over 10,000 warheads, a simultaneous firing of even 30% would be enough to wipe out almost every city with a population exceeding 500,000 people so any sort of medical care or surviving infrastructure is totally out of the question and even those who survive the blast and beat the fallout to currently uninhabited land would have little in the way of help. Hospitals aren’t usually built in the wilderness.

Far from being just a simple truism born of fear, the notion of a nuclear apocalypse that could destroy modern civilization and even trigger a mass extinction in its wake due to radioactive fallout, is probably a very accurate description of what would happen should a full scale global nuclear war break out. While there would be quite a few survivors, they would have virtually no infrastructure to power their homes, deliver water to farms, or fuel their cars, and the electromagnetic pulses generated by the blasts would take out virtually all communication networks. Cut off from the world at large and the basic services we consider the hallmarks of modern society, they would be living in a radioactive world with few supplies, an uncertain future and almost feral rules. Maybe, just maybe, it’s not a good idea to stop worrying and learn to love the bomb…

update 04.20.2010: It’s been brought to my attention that an average nuclear yield of 1 megaton was probably too high and a more accurate figure would be closer to 350 kilotons. The fallout cloud from that blast could be lethal over an area of roughly 5,000 km² and considering this adjustment, the total number of warheads we’d need for the scenario detailed in the post is 3,724, about a third of the total nuclear stockpile. So we could say that it would take only 283 megaton warheads and 3,724 average nukes to end civilization as we know it.

[ illustration by Ryan Kelly for Wired Magazine ]

  • Zar

    While the maths here paints a more realistic picture then David McCandless, and does answer the question posed, I still doubt a nuclear war would be the end of the world. Would weapons be launched at Africa, South America, Indonesia, Australia, New Zealand? It seems realistic to me that it would have been and still would be the Northern hemisphere that bears the brunt of any nuclear exchange.

    How far would the fallout reach, that’s the interesting question.

  • Just Al

    There’s a lot more in there that hasn’t been taken into account, too. While I don’t have the original numbers handy, there was the very real risk that past a certain number of bombs, the particle matter (radioactive or not) suspended in the atmosphere and meteorologic effects would induce “nuclear winter,” which would wipe out the total food supplies throughout the planet within a few years. This was supposed to be one of the factors of the single asteroid strike 66 million years ago, and if I remember right it’s even a concern with two many volcanic plumes too close together in time.

    Then of course, there’s the EMP effects from high altitude airbursts which would destroy the power grid and a very large percentage of all electronic devices directly, and cause millions of deaths from electrocution from the sudden electrical charge created in anything metal of adequate size. That would be enough to trash the infrastructure all by itself, without any direct deaths from the initial explosions or residual radioactivity. This is limited, however, to a certain radius beneath the blast. Scant comfort – it’s a big radius, and losing power and communication indefinitely from totally fried equipment is enough to generate some strong ripple effects. And while this may be limited to industrialized countries (with some indications that the Soviet Union had “hardened’ some of their vulnerable systems against it,) very few nations on Earth are economically independent and it’s hard to say what impact this would or would not have. Not “total destruction of life,” certainly, but at that point it might be a silly thing to argue about.

    But yeah, it’s definitely a bad report when it fails to take into account the fallout, which was/is the strongest effect of nuclear weapons, and has even entered our vernacular.

  • UNRR

    This post has been linked for the HOT5 Daily 4/20/2010, at The Unreligious Right

  • Greg Fish

    It seems realistic to me that it the Northern hemisphere that bears the brunt of any nuclear exchange.

    Zar, in a real world scenario, that’s very likely to be the case. But here, we’re trying to see how many nukes it would be required to destroy or irradiate all populated areas across the globe. As for your question about the reach of nuclear fallout, it could very well affect much of the planet though how far the radioactive particles will ultimately reach would depend on the winds and weather patterns.

    Again, we’re not trying to “end the word” per se, simply destroy modern civilization as we know it, break down all social order and government control, reduce the majority of cities and towns to radioactive rubble, and trigger a mass extinction while we’re at it. Though all that happening over a period of just a few hours or days sounds a little like the end of the world as we know it to me…

    there was the very real risk that past a certain number of bombs, the particle matter (radioactive or not) suspended in the atmosphere and induce “nuclear winter”

    Al, the original calculations by Russian physicists looked at the probability of mini ice ages triggered by nuclear war and I’m pretty sure that we don’t have enough nuclear weapons to do that. In the post’s scenario, it’s very likely that the clouds of ash, dust, debris and noxious gases would be comparable to several major volcanic eruptions and affect weather patterns, causing abnormally cold temperatures for years.

    then of course, there’s the EMP effects from high altitude airbursts…

    Any nuclear detonation produces a powerful EMP and a burst of gamma rays, taking out virtually all electronics for tens of miles from the blast’s hypocenter. There’s a way to shield computers, cars, planes and phones, but only military hardware is likely to be insulated. Civilian electronics are almost certain to be fried and useless, which is why I mentioned that survivors would have no communication or infrastructure. They would be taken out by a triple punch of heat, shockwaves, and radiation which would include the aforementioned EMPs.

  • bilhouse

    Fallout isn’t the end of it. The environmental impact of even a regional nuclear war (e.g., between India and Pakistan) could be devastating to the entire world. Smoke from firestorms resulting from the war could create a cooler, drier Earth. Food production would plummet and people would suffer all over the world regardless of hemisphere. This isn’t certain, but it’s from a study reported in Scientific American in January 2010 based on computer models and corroborated by observations of volcanoes, forest fires, etc.

    See: “South Asian Threat? Local Nuclear War = Global Suffering” by Alan Robock and Owen Brian Toon,, January 2010


    Did you hear about anti nuclear/uranium debate. It is here

  • aeiou

    While I’m not sure where you get your numbers for the lethal fallout zone that you quote in the update, in the main part of the post where you talk about the fallout from a 1 MT bomb, your numbers are badly flawed. The website you cite gives the lethal fallout distance as 90 miles *downwind* of the explosion. In this case the lethal fallout zone would be an oblong cigar-ish shape (as seen here) rather than a circle (and if there were no wind the fallout would be a circle, but with much reduced radius.)

    Using the 90 mile figure as a circular radius rather than the length of the oblong cigar shape overestimates the area of fallout lethality by a factor of about 7 or 8. This doesn’t really matter in your initial discussion of 1 MT bombs since the total area covered is still well over the inhabited area of the Earth. If you’ve used a similar method to estimate the fallout area from smaller bombs in the update, however, reducing that area of destruction by a factor of 7 or 8 means the difference between total destruction some decent sized chunks of the inhabited world surviving.

    Also, unless the attacks were planned to be timed with the weather’s wind patterns, a large fraction of those cigar-shaped fallout regions would overlap, increasing the fraction of land that’s still survivable.

  • Greg Fish

    Aeiou, very fair points on all counts.

    However, I would still doubt that the land anywhere near all these oblong fallout zones would be livable because the winds do shift and enough radioactive debris would be in the atmosphere to come back around and contaminate previously untouched areas.

  • Doug

    While it is fine to fear nuclear weapons and the extent of their potentials, there is a much greater and more realistic thing to fear…God’s curse towards mankind and the certainty that this world grows old like a garment. Scripture assures us that the fate of this present is sealed and doomed. Personally I am astounded at God’s mercy and long suffering with us. In spite of our inability to love one another, our inability to respect this wonderous creation and most of all our disregard of God’s will, we STILL continue still to enjoy so many blessings even in a world packed with some seven BILLION rebellious creatures! But one does not need to look around very much to see how dismal our future is becoming even without considering the coming annihilation of this planet. How much more can this world take of man’s inhumanity toward his fellow man? How much more can the environment we live in take of our abuses? I think perhaps May 21 of 2011 WAS judgment day after all even though it did not pan out as precisely as those who so diligently examined the Scriptures had assumed. There was after all no rapture and no five month period of terror ending with total destruction and yet for the first time a warning for a date of judgment DID go into all the world! It was a warning derived not by the dreams and visions of crackpots or by use of any revelation outside the Bible alone and that SHOULD have scared at least the “christian” 1/3 of this world’s population to death! But what happened was a response of mocking the very idea and what most of the very few folks that looked into it did was to look only for ways to dispute it rather than to fall on their knees and beg for mercy to understand if this was indeed about to take place. Someone once coined the term “eleventh hour” and then “five minutes until midnight” I think it’s likely we are now just minutes or even seconds away from “midnight” The only thing I can think of to do at this point is just beg daily for mercy…mercy to escape the same end that awaits the overwhelming majority of folks on this planet. Scripture says that judgment begins with the house of God…if that is what May 21 signified then the judgement of the rest of us follows that….The Bible says things seemingly contradictive in that while stating “of that day knoweth no man..” it also states that God will do nothing except He reveals it to His servants the prophets” But a “day” to God is not the same as what we assume a day to be, the day of the Lord could easily span months or years and still Biblically qualify as a “day” It is prudent therefore to assume we are in in that “DAY” of judgment awaiting the final execution…the thing to do therefore I believe, is to cast off our own wisdom and do as the the Ninevites did when warned of their impending doom “cry mightly to God”, repent and beg for mercy…Who knows if He might yet have mercy still on some of us? Stay OUT of the churches and synogogues and mosques and temples and go right to God through reading the Bible and praying to Him for mercy! He is exactly THAT kind of God that might have mercy on such! While we are yet alive there is hope but as long as we remain in pride there can be no hope. Bottom line? Don’t fear man…FEAR HIM that created ALL…FEAR Christ! Hope in Christ! Consult that glorious Book of truth…THE BIBLE!

  • Greg Fish

    Doug, you’re new here, aren’t you? The fire and brimstone preacher tryouts are down the hall and to the left, this is the science room, we talk about things that actually have evidence for their existence…

  • John Clarkson

    Greg, that’s quite funny! However, I’d have to also insist, that the nuclear physicists need to also go to another room. The one that says: “Prison for Unintelligent beings (who believe they are intelligent) who have given Nukes to Dirty corrupt lying Machiavellian Politicians”. I’ve got loads of evidence for that one by the way…ha! ha! ha!
    As for the piece above, I think it would depend largely on where and how you drop the nukes, what yield they have, the weather conditions, airburst or ground burst and the prevailing wind directions, effects on ozone, climate and fall out lethality to work out how many people would be anihilated in reality. Anything else is not worthwhile calculating.