How long could a zombie apocalypse actually last?

[Crowley]

I came across some people talking about The Walking Dead and how logically the zombie apocalypse should be pretty much over by now. This got me thinking. Let's take a "scientific" zombie apocalypse where it's not literally walking dead but people with some kind of infection that turns them into mindless ravenous rage monsters. The Walking Dead, 28 Days Later, World War Z... Now, these are still living beings, and as living beings they require energy and nutrients and thus need to eat. We have a global infrastructure to produce food and transport it where needed. If somewhere around 90% of people turn into zombies, how long could they actually sustain themselves in regards to food? They are usually depicted as purely carnivorous, and lacking the intelligence to even understand the concept of food in containers that seals out the smell. They also wouldn't be intelligent enough to use any kind of tools to hunt for wild animals. By all logic it seems to me that a zombie apocalypse should be over pretty quickly simply because the zombies would starve away.

[Independent George]

I came across some people talking about The Walking Dead and how logically the zombie apocalypse should be pretty much over by now. This got me thinking. Let's take a "scientific" zombie apocalypse where it's not literally walking dead but people with some kind of infection that turns them into mindless ravenous rage monsters. The Walking Dead, 28 Days Later, World War Z... Now, these are still living beings, and as living beings they require energy and nutrients and thus need to eat. We have a global infrastructure to produce food and transport it where needed. If somewhere around 90% of people turn into zombies, how long could they actually sustain themselves in regards to food? They are usually depicted as purely carnivorous, and lacking the intelligence to even understand the concept of food in containers that seals out the smell. They also wouldn't be intelligent enough to use any kind of tools to hunt for wild animals. By all logic it seems to me that a zombie apocalypse should be over pretty quickly simply because the zombies would starve away.

I've got no respect for 'Slow Zombies', unless they are highly contagious and can spread by blood droplets in the air, or if animals (like birds or insects) can spread it. Even then, all it takes is one well-equipped NBC unit to establish a safe point, and then should be able to organize at least an evacuation.

To take your specific examples:

1. Walking Dead - in the developed world, the zombies should have been slaughtered within 6 months. As far as I can tell, the zombification only occurs after a person is killed (whether by a zombie or other not); it seems to be a virus that takes over after normal life functions stop. The zombies can only be killed by a headshot, but they can be disabled by landmines, don't know how to take cover, and have no defense for being run over by an Abrams tank. It doesn't matter that the zombie isn't quite "dead" if its legs are broken to splinters; at that point, walking is not a question of willpower, but physics. The tough part of the learning curve is when the corpses in the morgue start slaughtering people behind the lines, but that's really not a hard lesson to learn from, and defend against.
2. 28 Days Later - Zombie takeover is unstoppable. They can transmit by atomized blood droplets, and animals are carriers. An effective defense is near impossible, and logistics is daunting as food supplies have to be tested for taint. The only defense is what was described in the film - hold out and wait for them to starve, but the zombies were only a vectors for the rage virus. There's nothing stopping the next generation of zombies from forming when "clean" supplies can be tainted later on by animals.
3. World War Z - Zombies get slaughtered. Brooks basically required the military to be complete morons in order to give the zombies the advantage. I haven't seen the film, so I can't say how that might be different. Unless it's the zombie virus that causes people to act like idiots...

[Admiral X]

The thing I've noticed about most zombie stories is that the zombies are usually somehow able to keep from rotting completely as a normal body would, and yet starving never seems to be an issue because they are literally supposed to technically be dead already. Yet nothing is ever said of what becomes of the flesh they eat, since if their bodies are dead, anything they ate wouldn't be digested so much as slowly rot in their stomach, which I would think would fill up and burst before too long. Also while some of them, like the World War Z book, will describe zombies as freezing, others seem to either ignore this or explain it away.

[FaxModem1]

World War Z explained what happened to all the eaten flesh. After a while, all the human and animal flesh in the zombie's guts explode and you have walking corpses with holes in their guts.

The book was also heavily critiquing lack of political and military planning in order to present a better public relations image on the news. It was only when survival and effective strategy, not good PR, was the top priority did they reclaim North America.

[FakeGeekGirl]

There's no way the zombie virus could spread so efficiently if biting is the sole means of transmission. Think about it - rabies is relatively easy to contain, even before the vaccine. You quarantine or destroy any animal potentially affected, and hold a hunt for vermin species that most often transmit the virus to livestock and pets. andi n the era of the vaccine, you don't even do that - you vaccinate animals likely to be exposed prophylactically and vaccinate people or animals who have definitely been bitten, and there are several efforts to unobstrusively vaccinate wild animals to prevent the spread. So, like Independent George, I feel like any outbreak that isn't spread by other means is doomed to fail and fail quickly.

[Independent George]

World War Z explained what happened to all the eaten flesh. After a while, all the human and animal flesh in the zombie's guts explode and you have walking corpses with holes in their guts.

The book was also heavily critiquing lack of political and military planning in order to present a better public relations image on the news. It was only when survival and effective strategy, not good PR, was the top priority did they reclaim North America.

Politicians don't typically get to dictate battle plans - and even when they do, it still gets implemented by soldiers with more than two working brain cells. World War Z basically involved everyone in the military, from the top brass on down to the enlisted men, to ignore basic tactical fundamentals (let alone any zombie-specific planning) as a PR stunt. No reserves, no overlapping fields of fire, no mobility - during an attack on US soil. Soldiers have this irrational dislike of getting killed, and often take steps, on their own initiative, to avoid getting killed. They also talk to each other, and figure out ways of helping each other not get killed as a matter of course.

It's been years since I read it, so I can't remember any details, but I distinctly remember rolling my eyes at their Brannigan tactics - like not sending aerial reconnaissance against an enemy with no anti-air capabilities and that didn't know how to hide. Or not using snipers against enemies that had to close to melee range to attack, and had no concept of 'cover'. Or have some Blackhawks on standby to provide cover/intel. Or just pile into your APC and drive away if you find yourself running low on ammo.

Heck, how hard is it to set up a squad on a rooftop, clear the building & line it with claymores, pick off zombies until you run either run out of ammo or start getting swamped, then have the choppers pick you back up again, and repeat. Nobody in the first half of World War Z seemed to realize that zombies don't have ranged weapons, let alone anti-aircraft capabilities. You can literally drop in anywhere, shoot, retreat, and repeat, until you run out of targets.

ETA: Maybe I'm being too hard on it, but I specifically remember it being described/marketed as a 'realistic' depiction a zombie apocalypse and its response. It wasn't.

[FaxModem1]

They point out in the Battle of Yonkers that they did a LOT of that. The problem? Logistics. For every 100,000 of the things that they killed, a million more kept coming. Bomb them? Great, but they were unable to get enough munitions for resupply after the first wave. Run over them with tanks? Great, but they ran out of fuel, and stranded the tanks in the middle of a sea of zombies.

Snipers? Great, but they run out of ammo and are only going to serve as spotters until someone picked them up.

Another chapter in the book pointed out that the rest of the world was dealing with supply problems, and that was affecting the world economy. This affected the US as well. Yonkers was six months into the Great Panic, and was a desperation move to get the civvies to keep producing and not run for the hills because they would see on TV that the US military was taking care of it.

Problem was, military resources were already tapped in a hundred different directions trying to keep the peace and deal with local incursions. The fact that the so called vaccine was a placebo for the zombie virus didn't help matters.

[ScreamingDoom]

I remember reading a digest of a study done by a couple of Canadian mathematicians who tried to model how a zombie apocalypse would go down.

The critical period was the first twelve hours after Patient Zero. If the outbreak could be recognized and contained within that time period, the zombies always lost. If not, humanity would likely be destroyed. Other simulation rules they adopted was that bites were always fatal, reanimation happened within one hour of death, and the initial outbreak happened in a major metropolitan city (I believe they used Vancouver as the model city for the simulation).

The biggest problem was recognizing that a zombie outbreak was occurring and dealing with it appropriately. The model assumed that no one knew of (or, at least, seriously considered) corpses coming back to life to eat the living to be a threat. The first places to succumb were hospitals, which in turn exacerbated the problem of recognition and containment. People exhibiting symptoms after bites or interaction with infected tissues would quickly stop going to medical facilities, which in turn would spread the problem throughout the city. The military cordon would break down quickly as panic rose and then the zombie plague would quickly spread throughout the world.

No word on if Madagascar would immediately close its borders, though.

Interestingly, the report supported the common zombie movie idea that the real problem in a zombie outbreak is not the walking dead themselves, but the breakdown in social order that such an event would cause. As long as society remained cohesive, the zombies could be contained and dealt with relatively easily.

Dealing with a zombie outbreak would require some politically distasteful shows of force, however, up to and including the use of atomic weaponry, depending on how long it took to get a grasp on the situation and how badly social order had decayed. It would almost certainly require the use of military assets in any event; local law enforcement and private security would not be able to handle the walking dead.

The mathematicians also ran a simulation in which a cure for zombism was available; here, humanity is never wiped out, but neither could it recover to the extent that the undead would be destroyed, either. Instead, an equilibrium is reached where the zombies can't kill people fast enough to exterminate humanity, but humans don't have the infrastructure available to cure zombies fast enough to wipe them out either.

It's not quite the situation the original poster asked about, as the model assumed full undead status and not just people infected with HyperRabies.

[Naldiin]

They point out in the Battle of Yonkers that they did a LOT of that. The problem? Logistics. For every 100,000 of the things that they killed, a million more kept coming. Bomb them? Great, but they were unable to get enough munitions for resupply after the first wave. Run over them with tanks? Great, but they ran out of fuel, and stranded the tanks in the middle of a sea of zombies.

Snipers? Great, but they run out of ammo and are only going to serve as spotters until someone picked them up.

Another chapter in the book pointed out that the rest of the world was dealing with supply problems, and that was affecting the world economy. This affected the US as well. Yonkers was six months into the Great Panic, and was a desperation move to get the civvies to keep producing and not run for the hills because they would see on TV that the US military was taking care of it.

Problem was, military resources were already tapped in a hundred different directions trying to keep the peace and deal with local incursions. The fact that the so called vaccine was a placebo for the zombie virus didn't help matters.

I'm going to have to disagree here. The problem here is that Max Brooks - and for that matter, most authors of science fiction - have functionally no concept of just how lethal modern military kit is. Zombies may be able to stay 'alive' with only their brain tissue intact, but without functioning legs or muscles, they still can't walk - as Independent George notes above, it's a matter of physics, not of willpower.

So the problems with the Battle of Yonkers:
1) There's no reason for soldiers to rout who can be withdrawn in stages before they are overrun. Modern mechanized infantry could simply stage a fighting withdrawal down the highway if ammunition ran short. Defeat would require units refusing to fall back when overrun, which would require contrived stupidity.
2) The battle is inexplicably fought completely in opposition to US military doctrine, which emphasizes speed and maneuver over entrenchment and static defenses. The excuses are somehow that this is 'old cold war thinking' but that's simply not how the US military expected to fight conventional conflicts, even in the cold war. The tactics of the 'Battle of Yonkers' aren't circa 1985, they're c. 1916. They were obsolete by 1917, much less the present.

But the biggest, and I'll elaborate at length:
3) Modern Weapons are more lethal than this.
A single GBU-10 Paveway bomb can kill pretty much everything to a range of around 300m. Fuel-Air (or Thermobaric) bombs can do *much* better than that. Humans out of cover are likely to sustain massive injury even 800m from a GBU-10. If you have funneled an attack on to a highway, simply dropping one bomb every 10 minutes or so would be enough to completely shut down the attack route. Even if the zombies survive the blast, they're likely to be crippled and so easily disposed of by a static defense position, say, 2 or 3 miles down the road.

But that would actually be overkill - you don't even need bombs. The Battle of Yonkers works on Hollywood bullets which (to keep that Pg-13 rating) burst a single bloodpack and cause otherwise photogenic death. Real bullets, especially large caliber bullets from things like a vehicle mounted M2 (Ma-Deuce, mounted on many Humvees and (I think?) all Abrams tanks) can tear the body apart, and cause massive tissue damage even away from the primary wound because the high speed round sends damaging shockwaves of force through flesh. Again - 'zombies are already dead' is no defense - if the muscles are pulverized, or bruised beyond function, the body cannot move. Same goes for shattered bones, or severed nerves.

While smaller caliber service rifles (like the m16 or the m4 carbine) might be less damaging (note: 'less'), they're also going to have the advantage, against a large crowd of zombies, of putting bullets through multiple targets. 5.56x45mm (standard round for the m16 and m4) can go through a *lot* of body before stopping - I've seen tests with penetration of ~15 inches. And even a bodyshot will be a problem, even for a zombie, because that hit is doing to cause major tissue damage in surrounding muscle tissue, which you do, on the balance, need.

And that assumes some clever soul doesn't simply drive their tank into the crowd. An M1A2 tank is about 70 tons, and can get up to 45mph on the highway. It has an operational range of more than 250 miles, so it can drive up and down the highway for *hours* smashing everything in the way. There's an assumption that these tanks run out of fuel really quickly - tanks are massive gas hogs, but they have *huge* fuel tanks (~500gallons) to give them the necessary operational endurance. And unarmed zombies are simply incapable of actually damaging the vehicle in any way, *even if it is stranded* - they can't pull open the hatches and there's no other good way in. At best, they could pull off the treads and achieve a mobility kill, but even that would be damn hard (might be impossible).

And all of *that* ignores the most potent and effective killer of infantry in the open in modern warfare since 1914: artillery. Not fancy rocket artillery or air-power. Basic artillery using fragmenting shells. Artillery causes the overwhelming majority of casualties in the First World War (not machine guns), and for infantry out of cover (which is what zombies are) a battery of M777 155mm howitzers is murderously deadly. Effective range for anti-personnel rounds is ~15 miles. The howitzers would be, on the balance, far more deadly over an extended engagement than the MLRS mentioned at the battle.

And while I get that "oh, they were short on stuff and things were in use elsewhere" is part of the excuse, I think it's worth noting - this: https://fas.org/man/dod-101/army/unit/toe/ is the standard equipment load for US divisions. Even a single airborne division (perhaps the 82 Airborne, out of Fort Bragg, NC?) has multiple artillery batteries, and piles and piles of conventional firepower. And that's an *airborne* division.


So, no. The Battle of Yonkers is silly. Infantry cannot advance effectively in the open against modern military firepower. Cover and concealment are required (see on this: S. Biddle, Military Power), which zombies do not use. Magic is required in order to explain zombies winning an engagement with a modern military under almost any possible circumstances, outside of circumstances where the virus is super-contagious.

[Independent George]

I think part of the problem is that Brooks did the first level of research (found out the relative effectiveness of munitions in wartime), but not the second (put it into context). The reason it takes so many bullets/shells/bombs per enemy killed in action is because the enemy is actively shooting back, moving, and taking cover. Zombies don't do that. And when you have the concentrated mass of bodies described in WWZ, that should make artillery more effective, not less.

Leaving all that aside, what really bothered me about the battle of Yonkers was the apparent complete lack of intel on the zombie numbers. They don't exactly try to hide from aerial reconnaissance - so how exactly did 10M manage to sneak up on them? Come to think of it, that's actually one of the things that always drives me nuts about zombie movies, too (how do they manage to constantly take people by surprise in open areas?).

I can suspend disbelief in a traditional zombie movie, but not when the work is specifically meant to be a 'realistic' portrayal. Again: I haven't the slightest problem with 28 Days Later - it made perfect sense according to the internal rules established by the movie. World War Z and Walking Dead don't pass that test in my mind (though I haven't read the original comics, so it may be a matter of translation/television budget for the latter).