Could humans sustain life after a k-t like extinction event? I know that a long lasting winter was a side effect then, but humans have technology to protect against cold. What other effects of an asteroid strike could humans potentially not recover from?

  • $\begingroup$ Are you assuming exactly the same size and location of impact? An ocean impact would be a different type of event from a land or shallow see impact. $\endgroup$
    – Slarty
    Oct 20, 2017 at 17:49
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    $\begingroup$ Probably not since smaller species of mammals managed to survive to the present day, but without internet there won't be life as we know it. $\endgroup$
    – user6760
    Oct 21, 2017 at 1:58
  • $\begingroup$ I recommend reading blackout by Marc Elsberg, it's about what would happen without power and very well researched. Then take that situation, multiply with natural disaster and decades of no power and you'll have a good estimate. $\endgroup$
    – DonQuiKong
    Oct 21, 2017 at 10:14
  • $\begingroup$ Some people predicted that the recent hurricane hits in the Gulf region should have killed thousands, if not hundreds of thousands. Consider that there WERE thousands (if not hundreds of thousands) of deaths in these hurricanes, but of other species, not humans. It seems that predictions of the number of human deaths from natural disasters far exceed the reality. Humans are like cockroaches - very difficult to kill. Somehow, we survive even the most devastating of events. There were human survivors of Hiroshima and Nagasaki, who defied all odds. $\endgroup$ Oct 21, 2017 at 15:37
  • $\begingroup$ This question is very simply too imprecise to answer. A "k-t like extinction event" quite simply covers 3 orders of magnitude of damage. $\endgroup$
    – Fattie
    Oct 21, 2017 at 15:53

8 Answers 8


A large meteor impacting would have devastating consequences on the planet, and humanity. Tsunamis would wreck countless thousands of miles of coastline. Ships would be sunk. Infrastructure destroyed. Seismic activity would cause further death and destruction.

And on top of it all, the debris thrown up into the atmosphere may well obstruct the Sun, such that our climate experiences dramatic shifts (think mini-ice age) for the next few decades.

Under these circumstances it is doubtless that millions, if not billions of people would perish. Disease would run rampant as governments would struggle with the aftermath of the disaster. Food, medical supplies, and transportation would become scarce in the immediate aftermath.

Look at Puerto Rico: one month after having been hit by not one, but several natural disasters, they have yet to restore power their electrical grid - and that's with other countries lending them a helping hand. Only the riches, most organized, and efficient of nations would be able to recover in the aftermath of such devastation, and even they would doubtlessly struggle, and not be able to save all of their citizens.

Many (maybe even most) nations would collapse in the face of massive civil unrest due to the unavailability of food. Urban centres depend on continuous food deliveries from surrounding farms, and abroad, which would come to a stop in the face of fuel shortages.

Imagine walking up to your local supermarket and witnessing a crowd of thousands fighting over the last few remaining foodstuffs left on the shelves. The situation would doubtlessly devolve into violence and barbarity.

Governments would be juggling trying to save the wounded, and displaced populations, repairing infrastructure, and putting a stop to the violence and looting.

Would humanity be wiped out as a species? Most likely not. There are too many people, in too many corners of the world for us all to die off. And we have the technology to survive in some very extreme conditions (think nuclear bunkers capable of hosting survivors for years, maybe even decades).

Would all civilizations survive? No. Most would undoubtedly collapse. The current world order would not survive, and from the ashes, likely a far harsher, more ruthless civilization would arise.

And also keep in mind that as resources become scarce, and land which was once fruitful is covered under layers of ice, nations may well go to war and try to capture new, warmer territories. Who knows how many will die in those no-holds-barred conflicts? After all, there will be no global "peacekeepers" left to enforce any world order what with each nation in a state of crisis.

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    $\begingroup$ "Only the riches[t], most organized, and efficient of countries would be able to recover in the aftermath of such devastation." Actually, your example of Puerto Rico has another, perhaps unintentional, point: it is taking them this long in a world where pretty much everything else is ticking along normally. Now consider what would happen if a decent part of the world was affected, rather than a relatively small geographical area. $\endgroup$
    – user
    Oct 20, 2017 at 18:49
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    $\begingroup$ @MichaelKjörling - 100% correct. They would most likely never recover, and their population would likely descend into barbarity, slaughtering one another for food/shelter/medicine, or simply because they can. The situation in such a country would quickly devolve into "end of times" anarchy. $\endgroup$
    – AndreiROM
    Oct 20, 2017 at 18:52
  • $\begingroup$ "Would all civilizations survive? No." Especially since the Chicxulub crater is just south of the economic Big Dog, which would -- as you say -- get wiped out. $\endgroup$
    – RonJohn
    Oct 21, 2017 at 11:05
  • $\begingroup$ This doesn't really answer the question. You should edit in a part on whether or not you think that humans would go extinct. $\endgroup$
    – kingledion
    Oct 21, 2017 at 19:48
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    $\begingroup$ @kingledion - you mean the sentence that literally says "Would humanity be wiped out as a species? Most likely not." ? $\endgroup$
    – AndreiROM
    Oct 23, 2017 at 13:46

Short answer: No.

That event killed in three waves.

  1. Impact. Local.
  2. Heat blast and tsunami.
  3. Decreased light/plants die (several years at least; global.)

But, 30% of species lived, and we are more mobile and adaptable. We only need ~100,000 humans to survive, for the species to be just fine, long term. That's less that 0.0001% of people. 1 in 100,000 people. One person in a town of 100,000.

The creation of new niches will allow radiative evolution (think millennia) but humans will be fine. We are mobile and adaptable in ways that 'animals' aren't.

  • $\begingroup$ While a community of 100,000 people provides sufficient genetic diversity to repopulate, those people would have to be relatively close to one another. If you have less than 40,000 on each continent (for instance) with no method of interacting (lacking infrastructure for long distance travel etc.) it would effectively be as though only 40,000 people survived for genetic diversity. $\endgroup$
    – GOATNine
    Jun 20, 2018 at 12:07

Not unless humans themselves will help to get extinct.

Cretaceous–Paleogene extinction event is thought to be caused by asteroid impact, followed by massive firestorms and rapid temperature changes.

However dramatic these events are, humans are very widely spread and very well equipped to to weather out a catastrophe like that. Lets take a look at the different killing factors:

  1. The impact. The asteroid is estimated to have been around 10 kilometers across and upon impact some 100 teratonnes of TNT of energy equivalent was released. This is much bigger than all of current nuclear arsenals combined. However, the effect would be only local. About 1000 km from the impact site there would be no lethal force capable of killing people, apart from unlucky earthquake or tsunami.
  2. The fires. It is theorized (but disputed) that impact has caused massive firestorms. Global fires would have a greater killing potential than just the impact. However, there is no reason to believe that those fires could be global, and even if they are, there are still too many places on Earth where people would be little affected.
  3. Climate changes. It it theorized that global temperatures plunged about 7 degrees Centigrade for several decades and sunlight was substantially blocked. This probably had the most devastating effect on animals and plants. While 7C difference is in the same ballpark as the variation seen during recent ice ages, quick onset of the changes had likely exacerbated the problem. This change should present no rick to humans in warmer climates, but would make food production more difficult.

Overall, humanity as a whole should live through this event, but civilization as we know it will be destroyed. If survivors would engage in global wars, this may end the civilization entirely and put humankind on the brink of extinction. Without wars, there definitely will be survivors.


Yes but...
Such a large impact would probably kill at least 99% of people on earth. Many from the direct effects of the impact and many more from the knock on effects. Assuming the impact was on land or shallow sea the impact winter effect would be very serious causing crop failures and starvation on an enormous scale. It is reasonable to assume that such a shock effect would cause a systematic collapse of civilisation across most of the planet.

However I do not think it would be an extinction event for the human race. There would be areas sufficiently distant from the impact to avoid the worst of the initial effects and sufficiently populous and advanced to maintain at least a small part of their population by extreme measures.

Measures would include martial law and control of food stocks, culling (although they might use the term prioritisation) and expansion of the fishing capability by commandeering and converting all manner of vessels for fishing work. Although the oceans would also be affected, fish would not be driven extinct especially in areas remote from the impact. The advantage of fishing is it relies on wild food rather than planned crops. Although crop yields would be greatly reduced, some crops would be available.

Other survivors who could be added to the total number at some future point would be the crews of nuclear submarines and the many survivalists who hoard guns, bullets and beans etc. There would also be a few from other areas who ganged up and via violent means took control of food supplies in shops and warehouses in more remote locations. Especially in countries where effective government had been destroyed by the blast.


It probably depends where in the world it hit, along with the amount of long-lasting food and other provisions for humanity to survive on.

The only reason the asteroid that killed off the dinosaurs was quite so devastating on a global level was due to the fact that it hit a gypsum rich region on the coast. This went on to create a dense layer that blocked the suns light from reaching the surface, causing ecosystem collapse - so the megafauna starved.

Thats not to say that was the only cause of death from the asteroid impact - it also vaporised some, created deadly forest fires and resulted in the largest known tsunami - but if not for gypsum being thrown into the atmosphere from the impact, dinosaurs from much further away from the site (for example in south america) could have survived, as the ash cloud would not have been as dense and would have dispersed quicker.

-These conclusions are primarily taken from the 'The Day the Dinosaurs Died' - a documentary from the BBC, in which they look at the evidence surrounding the KT extinction events (such as Earth cores from the asteroid site along with fossil evidence-

But, even if the asteroid hit such a region, that wouldn't necessarily cause humanity to die out. This is due to the fact that we preserve and store food so it could keep for a much longer time - which reduces our chance of starving to extinction. However it would cause large-scale drought alongside other issues - so chances are, even if people survive, few societies will (as in, as we know them).


Yes, absolutely certain. Especially western technological societies would cease to function. Life as we know it would come to a halt. Look at the enormous impact that meteorite had back then. Almost all life perished. Well over 90%.

A lot of animals (and humans) would die due to the explosions, tsunamis and shock waves that would rock the planet, immediately upon impact. After that the sun would disappear for years behind a huge dust cloud. No sunlight, no photosyntheses. No food for us to eat, or for animals to eat. Expect mass starvation of the survivors.

That dark/dusty period would last for years, if not decades. It's not impossible some survivalists would have enough supplies to last that long, but there aren't many of them. They would live in a bleak barren world.

Most western people don't know how to grow food, or hunt. (Other than for bargains at Tesco or Walmart). Even if they can, what's the use? There isn't a society anymore. Hardly anything living, be it plant or animals.


How much time human have for prepare before impact? If few years or no time? Probably both case most humans die. But if have few years, can store food and water, important information for rebuild in underground libraries and in high orbit sphere satellites (they can point any direction, no need control their direction) with solar power.

Big problem is food and clean water for few years. People know can keep themselves warm with cloths and fire. Cold weather can help save food. For food, humans can eat insects, rats, dead animal, dead humans, roots, food reserves they find, until Sun bright enough grow food again. Some very lucky people like large ships crossing ocean (or train) with food like rice/grain (last long time and not need refrigerator) have enough food for years for their crew. They have maps and can find small island before ship use all fuel.

Most governments probably collapse because no extra resource for military and police for control people. People will form new local governments and solve their own problems and ignore current borders (always virtual lines) and work and trade with any people they want. People will use silver and gold for money and may be some old and maybe new paper currency too.

Some technology objects can survive long time and people can still use it even if people can't create new objects. Many infrastruture like roads, bridges, canals, house, buildings, dams, tunnels, train tracks, ship ports will survive. Many many cars and trucks, boats, some Otto and Diesel engines will survive for decades, can use alcohol and vegetable oil for fuel, and lubricate engines. Bicycles still work with no fuel. Small AC/DC electric motors/generators common, use wind or human power with bicycle parts for generate electricity. If can generate electricity, can use radio for communicate with people around world and some satellites, charge car battery, use small electronic like laptop use 12-24 V DC. Modern knowledge like sanitation/medicine/science/engineering/maps help even with low technology and will accelerate rebuild.

Humans work together and help/work together in emergency time, help find solution for problems (after emergency finish they compete/fight again), this help humans survive.


I would say yes.

The technology is dependent on a complex infrastructure. So when the oil and coal stop being shipped to power our technology, our technology is not going to be very helpful.

With 99% of humanity gone the technological society we have would collapse and after it does there is no way of restarting it (easily accessible fossil fuels have been used up, It takes a lot of technological to get to the ones that are left)

With 1% of the human race left and no technological there is every chance that the rest would simply die out.

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    $\begingroup$ 1% of seven billion people is still 70 million people. About the population of around 2000 BC. $\endgroup$ Oct 21, 2017 at 3:33

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