So, in response to my own earlier question: Disasters to prompt the bettering of civilisation, I have decided to go with an asteroid impact which decimates much of civilization, with an added twist that the chaotic events the asteroid causes are reminiscent of the cataclysms said to take place at Ragnarok in Norse mythology.

More specifically, the asteroid hits the North Pole, with the resulting masses of ice and dust released into the atmosphere blocking out the sun, hence the “three year winter”. War between major countries breaks out over now-scarce food and resources, with the largest nations, (like America) collapsing. Eventually, the masses of ice released into the air melt, deluging the planet with massive rainfall. Large areas of land are flooded, and all sense of order breaks down.

A few decades later, the climate stabilizes itself, and the survivors emerge: the few thousand people who retreated into large bunkers to wait out the crisis, and whose descendants come to repopulate the world. Learning from the mistakes of their ancestors, the survivors rebuild civilization as environmentally friendly as possible, and use gene banks to recreate the planet’s wilderness. Eventually, fear at a future catastrophe drives the new major governments to send missions into space to colonies Mars, Venus and eventually extra-solar planets.

Would this, as the basis for a project, work? That is, are there any major physical or sociological flaws in this plan?

  • 4
    $\begingroup$ This was realistic right up until you said, "Learning from the mistakes of their ancestors, the survivors rebuild civilisation as environmentally friendly as possible." That's 100% unrealistic. But to make a better point (and the reason this is a comment and not an answer): questions about character choices are off-topic. So that last descriptive paragraph should be deleted from consideration. (Although it's worth mentioning that starting with only a few thousand people it would take a couple of thousand years to build the population to the point you can send rockets into space.) $\endgroup$
    – JBH
    Dec 14, 2022 at 17:55
  • $\begingroup$ Depending on the time of year, the North Pole might not have ice at all. The northern Pole is not always froze over. $\endgroup$
    – hszmv
    Dec 15, 2022 at 16:10
  • $\begingroup$ Also most of the vaporized ice and water would fall back on the North Pole. There's very little precipitation in the artic because the polar air is so cold, it can't hold a lot of moisture vapor, so there would be a massive rain/snow storm... but it's putting all that stuff back where it belongs. The worst thing to affect humans would be the massive Tsunami, but humans do not make a habit of living along the coasts of the Artic oceans in large major urban centers. $\endgroup$
    – hszmv
    Dec 15, 2022 at 16:17
  • $\begingroup$ @AlexP a large asteroid impact throws up dust no matter where it hits, even if it hits deep ocean it STILL hits the land below it. and dust is thrown into the upper atmosphere, how cold it is does not matter at that point, it will circulate over most of the northern hemisphere. if it hits at an angle it can spray molten rock almost to the equator. $\endgroup$
    – John
    Dec 15, 2022 at 23:01

5 Answers 5


Due to how the atmospheric circulation works, I doubt that a large impact at the North Pole would spreads the dust in the Southern hemisphere.

Sure, ice melting would have an impact also there, but I would probably go for giving an edge to the nations from down under, which will be less affected by solar obfuscation.

  • $\begingroup$ What dust? The North Pole is in the middle of an ocean. $\endgroup$
    – AlexP
    Dec 14, 2022 at 20:22
  • $\begingroup$ I should point out at this point that the Chicxulub asteroid hit tithe Gulf of Mexico, and yet it sent up enough dust to wipe out the dinosaurs. $\endgroup$
    – user98816
    Dec 15, 2022 at 9:56
  • $\begingroup$ How much of the ice would even melt? Anything struck directly is atmospheric water vapor, sure, but 30 or 40 miles from the epicenter? Doesn't that just get cracked and rolled by some big waves? There should probably be tsunamics (sucks if you live in Scandinavia), but does this really introduce much extra moisture into the air? $\endgroup$
    – John O
    Dec 15, 2022 at 18:31
  • $\begingroup$ agree that a polar impact is not going to get much dust into the other hemisphere. but it worth noting that an impact of that size also sets off EVERY fault zone and volcano with any internal pressure across the globe. there are tsunami on basically every coast in both hemispheres. so the southern hemisphere still has a very bad time. It may also trigger an entirely new giant volcano on the other side of the planet, which in this case would be in Antarctica. $\endgroup$
    – John
    Dec 15, 2022 at 23:18
  • $\begingroup$ The atmospheric disturbance may effect the northern hemisphere, but you are probably right, the southern hemisphere may be saved from most of the climatic disaster. What they are not saved from is the socital impacts such an event would cause. Most of the worlds population lives in the north. The people in the south would be dragged kicking and screaming into the chaos of the north $\endgroup$
    – Sonvar
    Dec 16, 2022 at 19:35

They probably wouldn't need 'bunkers' or 'gene banks'

Overall, your disaster is plausible, but there are a few things that seem out of proportion or don't exactly fit together.

First, unless the asteroid is massively radioactive or something, people aren't going to need to hide out in underground bunkers. The Earth may be cold but it doesn't sound like it's poisonous. It would be a waste to spend scarce energy and resources building underground homes. Much simpler to just add insulation to existing houses. Above ground, you can build heated greenhouses and barns to produce food, etc.

Second, it doesn't seem like you're consistent about the numbers of survivors and extent of destruction. First, you talk about wars breaking out and large nations "collapsing". By "collapsing" I guess that you mean different regions will break apart and fight against each other. This suggests that much of the world's population (hundreds of millions?) is still alive, and that the world is still survivable (despite being too cold to produce sufficient food). Then you talk about the survivors only numbering a few thousand who survived only in underground bunkers; that seems to be a scenario in which all surface life was obliterated. So which is it? "Three-year winter" or total surface annihilation?

Thirdly, most plants produce seeds that can survive, dormant, for some period of time. Not every seed will survive for 20 years, but some will; enough for the forests and prairies to revive once the climate recovers. This is really not that long of an "ice age". Although some plants may be totally wiped out, most of the common ones (grasses, trees, weeds, etc) ought to re-grow from dormant seeds without assistance. Therefore, it doesn't seem likely to me that such a small and struggling population will be interested in 'gene banks' or devote their resources to a futuristic genetic engineering project to rebuild the wilderness. Animal species are another question but you would expect at least the common species to survive in some small numbers.

  • $\begingroup$ plus there are real seed banks we can use to restore species. $\endgroup$
    – John
    Dec 15, 2022 at 23:16
  • $\begingroup$ Possibly the OP means people hid in (pre-stocked and heavily fortified) bunkers to wait out the war, as some billionaires are planning to do in reality if disaster strikes, rather than to hide from the disaster itself. Being able to store enough supplies to last a few decades, or grow enough food inside an underground complex to be self-sufficient, seems a bit unlikely, though - but whether it's realistic or not, Fallout and various other stories seem to have got away with it, so maybe it's plausible enough for OP too! $\endgroup$
    – A. B.
    Dec 17, 2022 at 6:31

Let's start with a Chicxulub scale asteroid hitting our North Pole. This would immediately vaporize most of the arctic sea and make a crater deep enough to expose magma. More water would pour into it and immediately boil away until it cooled enough to form a circular ocean about 180 kilometers across.

You aren't talking about dust from that kind of thing, you're talking about pulverized rock. The theories about Chicxulub suggest that the rock thrown out of the atmosphere (like 1000's of miles out of the atmosphere) would rain down on the entire planet. The infrared radiation from it falling back to earth would raise the surface temperature in the northern hemisphere to more than 160 degrees F for several days. All of the Northern hemisphere ice would melt, especially Greenland.

Yes, tsunamis for everyone. Tectonics would also probably break the antarctic ice shelves free. Overall, sea level would rise by about 200 feet. I'd put money on Yellowstone popping like a zit, making things worse by spitting volcanic dust into the atmosphere. That, all by itself, would be disastrous. The volcanic ash will continue to fill the atmosphere for years, if not centuries.

The plant life that wasn't baked in the initial wave of heat would then be deluged with months of freezing rain. Normal global air circulation would recover in a few months, tops, but you'd still have a lot of excess dust and moisture. Most of the rain would come down around the state of Washington, the Mediterranean sea, and the Black Sea, because that's where the Hadley cells dump their moisture.

If you're counting on the Svalbard seed vault, you will be disappointed. The initial impact will melt the permafrost, and then particulates will block the sun, and freezing rain will bury it hundreds of feet deep in ice.

If it hit mid-winter, then there might be a chance of recovery for annual plants in the northern hemisphere. Perennials would all be toast, literally.

Throw any politics you like on top of this world. That's outside of the scope of this site.

  • $\begingroup$ burying it might make the seed bank more secure not less. $\endgroup$
    – John
    Dec 26, 2022 at 1:33
  • $\begingroup$ Secure, sure, but kinda hard to get to. A great archeological find for the next race to climb the evolutionary ladder. $\endgroup$ Dec 26, 2022 at 9:01

No. The premise of this is that the asteroid somehow throws already frozen ice into the atmosphere without it first melting, and then somehow staying in the atmosphere as ice. That's not how weather works. It is true that ice can be present in the atmosphere, but it is not believable that an impact of sufficient magnitude to throw dust up would also somehow create massive ice clouds that never rain for three years. Remember, this is the North pole - it is floating on water, so kicking up dust means an asteroid large enough to push through the ice cap (2-3 meters of ice) THEN push through the ocean below (up to 4000m!) THEN push into the crust with enough force to eject dust, and somehow also eject a bunch of ice. If such an impact would occur it would have to be larger than the one that destroyed the dinosaurs, which would make it so that a "three year winter" is the least of anyone's concerns.

However, you don't need the ice, you just need to alter the climate a bit. What you need is a long enough winter that food supplies are unsustainable. In your scenario, a smaller asteroid impact that takes out part of Northern Canada (or Siberia, I guess) and throws dust into the air somewhere like 2-3 times the 1815 eruption of Mount Tambora would cause a winter of sufficient magnitude without causing an immediate mass extinction.

  • $\begingroup$ the impact would not have to be larger than the dinosaur killer, any asteroid near that size punches through the ocean like it barely there. And yes the ice would not stay ice but in the upper atmosphere it might well turn back into ice. $\endgroup$
    – John
    Dec 15, 2022 at 23:04

I will go and push the "I believe" button and assume such an event resulted in a global environmental catastophy.

With your initial result of wars breaking out amongst the surviving nations. That may be plausible, when one nation struggles for their existance, they may look to acquire resources from their neighbors to ensure their survival.

Now, such wars do not pose much in the line of effecting natural selection at all, as many of the weapons that would be used is indescriminate, killing weak, and strong alike. I do not see any culture dominating the whole world, so no singular nation would dominate.

Now if the event was massive enough, and almost (if not all) governments would colapse, the resulting struggle would be more chaotic. People would engage in fighting and looting from each other. those who go into such event already prepare (doomsday prepers) would have a leg up on this. This chaos would last a few years until resources just could not be looted from others anymore.

This level of chaos does not bode well for developing an altruistic society later. Those who survived would tend to be more violent in nature. those that tended to be more peaceful would probably be the first to be victimized. their may be pockets of civilized people around, but they may have been decimated of the decades. however, those who did survive in peaceful communities, they would be the societies that would build back faster than the communities that maintained a violent natue.


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