A Little Background

March came and went, but the snow continues to fall on earth, even in Sudan and Brazil. What was once thought of as a miracle of Christmas has begun to cause problems. Winter came and with no signs of the coming spring, this is a problem.

People are beginning to panic, what was once a world wide Christmas miracle has become an icy hell, but they are not mass rioting for answers yet. Most people are looking to their government for answers, but they know nothing, and even if they do, no one is talking.In the foreseeable future, the winter would not end. Farmers have no way of growing crops and they are resorting to culling farm animals. Most of the world's freshwater lakes have frozen, crops can no longer be grown, etc. For all intents and purposes, this is a new ice age.

The Question

I could go on, but the the premise is simple, as are the small effects caused by it, but I'm curious about global survival. I have asked about the social effects of such an ice age, but now I am asking about survival. What can people do to survive? What can the government do? It goes without saying that unless the world can work together for this common goal, humanity is doomed.

How it happened is irrelevant. If it was caused by mankind, it isn't something they can just undo. But it just as easily may have happened somewhere across the galaxy and there is no way for humanity to stop it. How can humanity survive this New Age of snow and ice?

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    $\begingroup$ Santa Claus is coming to town... Evil organ music plays $\endgroup$
    – Ranger
    Sep 7, 2016 at 5:12
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    $\begingroup$ So, basically, you are describing Snowpeircer. They survived by never leaving close eco-system within the train with Perpetuum mobile for an engine. Just change train for underground bunker, change Perpetuum mobile for power plant of some kind (possibly geothermal, since nuclear one would be overproductive) and you are all set. $\endgroup$ Sep 7, 2016 at 5:40
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    $\begingroup$ The question is very Northern Hemisphere centric. It's summer during Xmas in the Southern Hemisphere. If it was snowing down under too at Xmas, the wake up call be earlier than predicted in the OP. Or does the Southern Hemisphere have to wait for a snowy winter by mid-year? $\endgroup$
    – a4android
    Sep 7, 2016 at 7:29
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    $\begingroup$ The Starks would have a gods damned field day. $\endgroup$ Sep 7, 2016 at 11:28
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    $\begingroup$ @Sky: a few billion years and we're toast, the sun will get hotter and (eventually) much bigger. By the time the sun's a white dwarf and goes (relatively) dim, we've been through a phase of the earth's surface being molten and possibly of the whole planet being vaporised. A bit of snow doesn't really compare ;-) We're due a regular ice age "any millennium now", should global warming permit. But like Remco says that's not as bad as a snow-covered earth. $\endgroup$ Sep 7, 2016 at 15:43

11 Answers 11


First off, I expect that governments will not play a large part in this. A global event like this has unimaginably large consequences, and I don't think there's ever been a large government in the history of mankind which has the agility to deal with this. There will be death. There will be rioting. There will be a breakdown of society. That is a reality to face.

But that's not the certain end of humanity.

Humans are marvelously resilient creatures. Some will band together and begin to survive. Most likely they will be groups under 150 people, which is Dunbar's Number, and they will each come up with their own solution to survival. Eventually those who survive may begin to merge back together and start forming what you and I would call civilization, but that's the easy part. The hard part is getting there.

We won't be able to bulldoze our way through this, like we love to in so many crises. There is not one solution which we can list which saves humanity. We're going to need to do what other animals do: listen and find our place in the planetary web. What we do to survive depends highly on what other animals do, because we're going to have to coexist with them... and likely eat them. (which is sort of coexistence... in a Hanibal Lecter sort of way)

The oceanic food chains are going to be our best bet. The sudden freezing of the world will raise hell on terrestrial ecosystems, but the ocean's raw body of water will serve as a temperature buffer giving more time to adapt. I'm not talking about Darwinian evolution here, because this will happen far too fast for that, but the different balances of species will have to adapt to the new climates.

The food chain found in Antarctica provides some hints as to how we might survive. Baleen whales, gargantuan graceful creatures, survive these extreme environments by eating low on the food chain. It is reasonable to surmise that the sort of plankton and krill which form the basis of the Antarctic food chain might spread north, so we may be able to leverage that food source. It's also possible that the Arctic food chain from up north progresses downward (giving us a chance at land-walking meat).

I would expect that the native people of these extreme regions, such as the Eskimo and Inuit, will have little trouble. Maybe we'll be willing to learn from them, and maybe they'll be willing to share their way of life.

  • $\begingroup$ Did you mean no government has the agility to handle this or no government has the ability to handle this? $\endgroup$
    – Skye
    Sep 7, 2016 at 12:25
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    $\begingroup$ I didn't write it but would suggest "both". $\endgroup$
    – AnoE
    Sep 7, 2016 at 13:43
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    $\begingroup$ I'd never even heard of Dunbar's Number - but the link included some very interesting reading. Learn something new every day... $\endgroup$
    – Ghotir
    Sep 7, 2016 at 15:31
  • $\begingroup$ @Sky I intended to use "agility," though AnoE is correct that both work. A sudden change like this would destroy any government which tries to hunker down and use their old ways of thinking to solve the problem, so the only solution that has a chance to work is to be agile, moving forward to new approaches. I wanted to draw attention to the fact that it's the ability to adapt that is going to matter here, not the ability to bear down and control things. $\endgroup$
    – Cort Ammon
    Sep 7, 2016 at 17:05
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    $\begingroup$ I find it unlikely that the US, Russia and China don't have serious nuclear winter plans. They may include things like "all civilians freeze" but I'd bet they exist, and probably would not fail day one. $\endgroup$
    – user25818
    Sep 7, 2016 at 19:25

If you want to know what happens, when it's suddenly cold and you are not prepared, read about Sybiraks - Polish people sent to Siberia by Russians. In your situation, a whole planet faces what they did, except for Russian guards, of course.

Key points are:

  1. Lack of proper shelters and clothing kills fast

  2. Proper shelters and lack of proper clothing means you have to improvise, or people start to starve in barracks.

  3. Fuel is life. Be it wood, charcoal, oil. Whatever keeps you warm and allows to melt snow for drinking.

  4. Surprisingly many organisms can survive winter like that. Permafrost regions still have woods, grass and so on. As long as there is enough sun, you can have valid ecosystem.

The death toll among Poles was great, but they learned from natives. Surprisingly, if documents are right, only about 5 ~ 6% of those who arrived, died. And they started without clothing and with bad shelters. Of course, they had an ecosystem suited for something really close to perpetual winter, and natives to learn from. And, of course, oldest and weakest probably died before. But still, whilst it was hell, it was surprisingly survivable.

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    $\begingroup$ Siberia is NOT a perpetual winter. Siberia has short, but quite hot, summer, when plants can grow and food for herbivores can recover. That would NOT be case in Snowball Earth. $\endgroup$ Sep 7, 2016 at 21:22

There are a few forks.

In the short term, some humans may adopt a sea-based hunter-gatherer survival strategy. Existing expertise with fishing is key here. The oceans have a lot of thermal mass, so they will take a longer time to freeze over.

Another short term strategy involves greenhouses and copious use of energy. Geothermal power will function (until things break down), and nuclear power with its insane energy density could hold up pieces of civilization. The hard part is maintaining the supply chains to keep everything working under catastrophy and chaos.

As time progresses, things get worse. A winter is different than an ice age. In a winter, the snow melts eventually. You can just push the snow aside, or gather it in an out of the way place, and wait.

In an ice age, there isn't enough space to push the snow aside. It continues to build up. Glanciers form, and the ice becomes geological. The ground, which contains minerals and organics, becomes buried and out of reach to surface organisms. Deposited organics gets buried under yet another and another layer of snow and ice, and becomes lost to the surface biosphere until melting occurs.

Even a sea-faring people need new materials, and even northern hunter-gatherers live on the land and get resources from it. So the sea-faring hunter-gatherers will be frozen out by the glaciers.

The nuclear and geothermal bases can continue a war of melting. If a good chunk of a continent can be covered in such nuclear/geological powered colonies the glaciers could be held back. But as ice flows towards gaps, you basically need to melt an entire continents worth of precipitation.

Total world rainfall is 5E14 tonnes. Melting water is about 300J/g. So to melt the world precipitation requires 5E15 watts of power. This is a K type 0.9 civilization, beyond our current budget. And way larger than what can be produced by geothermal (5E13) even theoretically.

The thing that can save us is that precipitation has to come from somewhere, which requires sublimation or evaporation. As the world freezes over, less and less water vapor will escape into the air. Clouds will die out. Solar power will become more practical.

The source of the ice age now matters. With clouds discounted, the sun's radiation will beam down on the Earth. The white earth will reflect more light, and together with if the sun's output is reduced it could explain a continued ice age.

Use of solar power at this point could help with pushing back the glaciers. But turning solar power into electricity, then melting ice, is less efficient than just heating up the ice directly. Put coal dust on the glancier tops and let the sun heat them up.

In the long term, things get worse. The oceans surface can freeze up, followed by deeper portions. Vents at the bottom of the sea remain melted, with liquid water volcanoes sometimes reaching the surface. All other life is gone (except possibly human nuclear/geothermal bases). Some think this may have happened in the past. The natural way to get out of it is to wait for vocanoes to emit large amounts of greenhouse gases, like CO2. With everything covered in snow and ice, weathering (which naturally removes CO2) and plants (rare, which consume it from the air) are missing. So the CO2 levels in the atmosphere build up to seriously large levels and the greenhouse effect kicks in. Things warm up, glaciers melt, albedo of of the Earth drops, things warm up more. If albedo drop outpaces weathering+live, the world continues to warm up. Eventually weathering+life+radiation start slowing greenhouse faster than albedo increases help it, and the world stabalizes with a melted ocean.

So a long-term defence would consist of finding artificial greenhouse gasses and terraforming Earth.

In the epoch term, whatever led to the cooling of the Earth may not be satisfied by simply painting it black. If the sun is dropping to 50% of its current brightness somehow, no amount of coal dust or greenhouse gases will prevent an iceball Earth.

Humanity would have to climb up to a K1+ civlization and stop being planet bound to survive, all while trying to live through a catastrophe. Desperate measures and technological revolutions would be required. Human extinction is by far the most likely result.

In the short term, non-industrial civilization could survive, but in the medium to long term only an massive industralized response to this crisis could surive. Things would be very precarious as a breakdown in any supply chain could wipe out all of humanity, and supply chains would be extremely hard to maintain over the frozen Earth.

It would take civilization-scale effort to rescue the human race from a rapid, total and unending ice age. The odds are we wouldn't survive, and at the least the vast vast majority of humanity would die. If we did survive, the civilization that emerged would be as different from today as modern industrial civilization is from ancient Egypt.


First concern: societal reaction. Food would run out fast. With crops dead everywhere but in greenhouses designed to withstand winters, food supplies would be severely limited. Riots, suicide, end-of-times predictions, etc. would cause populations to dip significantly. This would be felt the most in large population centers. Governments would topple, sometimes overnight, gangs would form, and chaos would reign for at least a couple of months. Disaster at a global scale is something humanity hasn't faced in recorded history, and even on localized scales, governments have a hard time keeping power because when people are dying, they begin to see that the government is, ultimately, irrelevant.

Second concern: Long term survival. Greenhouses would become commonplace overnight, with insulation, underground farming, etc. Anyone with access to such facilities would either be giving out those goods out of the goodness of their hearts or, much more likely, using that access to gain social goods that simply aren't available to anyone else. Eventually, those in power would accuse these farmers of selfishness and a complete lack of empathy in order to take over their facilities and place them into government control. Efficiency would fall as a result, which would wind up causing even more of the public to die off.

I see reliance on the ocean as a possible way out, but I also see a lack of effort in that direction simply because the infrastructure for supporting human life underwater is extremely limited (read: nonexistent) and would take years to develop. With a good chunk of the world's population on the brink of death, we don't have years to get our act together and engineering solutions on land is far easier.

In the end, humanity would prevail, but at the cost of a large portion of planetary populations and the loss of much infrastructure and social order. When the dust finally settles, new people would be in power (for better or for worse), new monetary mechanisms would be in place, and only a few population centers would remain. Flash-frozen jungles, meadows, mountains, rivers, lakes, etc. would cover the planet, perfectly preserving a record of what once was.

Once motivated in this way, I imagine the technology developed to continue to survive on Earth would be equally applicable to survival on the moon or on Mars, so people would begin to look skyward for an escape from a planet that has, ultimately, become hostile to human life.


That mostly depends on how cold it will get and how fast.

If there is time to prepare, let say a gradual decline in the temperature over a decade, many technological societies will have time to prepare.

To a genuine effort to be made, something clear must point to a long winter. Something like a measurable decline in solar output or a measurable change in Earths orbit. Actually is not a far-off idea. There is an hypotesis that a scenario like that happened a few times in the history of Earth. Not in a single winter, of course, but in a few times Earth was covered on ice even in the equator.

In a scenario such as this, most human population will die, no doubt about that. In a colder environment there is no way to produce enough food.

Fossil fuels, volcanoes, nuclear power and wind will allow pockets of technological population to be warmed. Indoors farms will be able to sustain decent colonies. That in the equatorial regions, of course.

Even if governments can't prepare, which is probable, many scientists, engineers and inventors can develop the necessary technologies to kickstart the winter civilization. Resources will be plentiful for those that survive. An oil wheel will last almost forever for a small community. Supermarket and factories of canned food will last for years. Dead frozen animals will be mined for quite some time. Engineering components will be harvested from cars, computers and buildings.

This new technologies will have to shift the concept of our society. We develop components and mine raw materials all over the world. The engineers will have to do with local goods. That means, nuclear power plants will run for some years and then be replaced by wind turbines and fossil-fuels that are easier to make and depends on widelly available resources.

And construction will change. Machines that work in normal temperatures does not work in the very cold. The Challenger explosion is an example of a machine designed to the summer launched in the winter.

Of course a percentage of the population will survive as hunter-gatherers like the Inuits. And they will move to everywhere in the world. With the seas frozen all surface can be walked on.

If gets even colder than our poles are today, People will have to live underground. Maybe even in stations isolated from the environment.


I have an idea for a novel about this topic.

In my novel, the sun began to weaken. (Try not to think too much on that) A new ice age has begun.

In my novel, scientist throughout the world have predicted this event and are working with the government to prevent the extinction of mankind.

They began huge projects to build enormous buildings powered by geothermal energy. To do this, each building would have a it's own drilling sector and they would drill straight to the Earth's mantle to collect the magma. Each of the buildings have large subterranean power plants to process the energy.

The building have sections for everything we need to survive. Lower levels for agriculture and mining(maybe), there will be civilian levels, manufacturing sections, etc.

These buildings will be build almost everywhere for humanity to survive. All that's left in the formula is generous governments...........

  • $\begingroup$ Might as well move to Iceland instead of having to drill all those holes. $\endgroup$
    – Skye
    Sep 7, 2016 at 13:09
  • $\begingroup$ Can you fit the world in Iceland? $\endgroup$ Sep 7, 2016 at 15:27
  • $\begingroup$ You can't store and fed 7 billions people in such facilities. There will be major conflicts to gain tickets to survival. $\endgroup$
    – Rigop
    Sep 7, 2016 at 15:58
  • $\begingroup$ Remember fallout 4 and 2012? People chosen are either rich or chosen for their genetics. $\endgroup$ Sep 8, 2016 at 0:24
  • $\begingroup$ There's no way that in an incoming ice age, everybody would survive. I would love to be optimistic that everybody would live through and have methods of survival but anything that can go wrong will go wrong someday. $\endgroup$
    – Skye
    Sep 8, 2016 at 12:16

If it suddenly turned out that it was going to be winter all the time, I'd immediately think about greenhouses.

This link describes a method by which a greenhouse that operates during all four seasons can be constructed. If you had trouble keeping the greenhouse warm, then you could use solar panels (or traditional oil/gas/coal) for heating.

So my answer to the question "how long can humanity survive" would be "indefinitely". I think an appropriate adaptation of the question could be "how much would the carrying capacity of the Earth be reduced?" (a lot). That would depend on the exact circumstances of your eternal winter.


In my opinion the greatest risk for humanity would be the onset of such a catastrophe. Realistically it would not be over night but rather decades till earth freezes but one of the first reactions should be war for resources. And it would be an all out war as the loser would surely die so mutually assured destruction is on the table. It could easily turn out the end for humanity. Also it will use a lot of the remaining resources.

Next would be the strife for technology to deal with the situation. In almost any scenarios it should be possible to find technologies to deal with new circumstances. May it be using geothermal energy, nuclear or even (less efficient) solar power. They might be even able to settle on another planet. The question is - will a group be able to develop and deploy such a technology before it's resources are used up and they starve or freeze.

Once just one group manages these two steps humanity should be safe despite living in permanent winter.


Extinction isn't really a probability in this scenario--Most of the people on the planet will certainly die, but not all.

Animals and People survived pretty much continual winter without our current level of technology. Today various small groups could easily survive by living and growing crops underground--my guess is there are probably already hundreds of places on the planet set up to do this.

Fuel will be a little tougher--but not that much. As long as you have food, machines and fuel you can run an oil rig. You won't need anywhere near as much fuel because nearly everyone will be dead--a single oil well could supply all of humanity.

Solar will be fairly useless, but wind will probably still work with some redesign and who knows, someone may invent a new "snow-driven" renewable power system.

I guess as long as we have shelter, power and enough clear, warm, illuminated space to grow crops--we'll survive. We'd make it for quite a while without power too-but it'd be a lot harder.

If you want to save, say 1-5% of the human race however it might not be possible.


Electricity can still be generated (in the same ways we generate it today). Thus, large indoor areas with heating can be maintained, allowing for shelter and crop growth.

We can also eat (and grow) seaweed.


OK, unless the world keeps freezing to the point that it reaches the Snowball Earth effect, people from any industrialized society, knowing what's coming, will move to the relatively warmer climate areas at the equators, where winter will not be so destructive.

Those who can will build and expand small cities around geothermal hotspots. In Iceland, around Yellowstone, by Etna in Sicily or by the Campi Flegrei in the Gulf of Naples...everywhere there is enough natural heat the industries will do their damnedest to pump up all the energy they can to warm up water, people and grow food in hydroponic greenhouses.

Genetic scientists will work with one purpose only: create crops with the maximum yield possible.

ironically, only by burning oil and carbon as there was no tomorrow would help heating up the atmosphere, but this glaciation would cripple the industries. And the armies of all surviving countries would have to shoot people to prevent burning what's left of the trees for domestic purposes. If all trees die, it would be an even more dire event in this chain of destruction.

It may also sound macabre, but corpses under ice will give the survivor much needed food. Just like it happened in the harsh winters during Stalingrad's siege.

The sea will be another precious, the only source of live food. Pirate wars will be fought for the conquest of the seas and their trove.

But even in this horrible, global chaotic situation, humankind can live, make through it as The Long Winter recedes decade after decade.


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