Where should I shoot a solar flare that is at least as strong as the solar flare(s) in 2012 for the most death? What else would happen? And how much death, in percentage of world population, would the solar flare cause?

That can also include the preceding flares that ""plowed the road" for the superstorm."

Yes, I know about Solar flares: “the week the earth stood still”"

Scientifically Possible, and possibly believable, please.

You can also include reactions to the Event as part of loss of life...

I know that I can't get vaporized bodies or spontaneous combustion via solar phenomena.

I suppose falling satellites and failing nuclear plants could do a lot of damage?

Okay, now we have an answer that could lead to total biosphere destruction... useful.

What if I didn't want anything other than solar flares and their after-effects?

  • $\begingroup$ This topic was explored in great detail in the novel Sunstorm by Arthur C. Clarke and Stephen Baxter. $\endgroup$
    – Philipp
    Commented Feb 7, 2015 at 15:58
  • 2
    $\begingroup$ I seriously doubt that a CME would cause satellites to FALL. Fail, yes. Failing nuclear plants would result in a lot of mass hysteria, but little actual damage, as with Fukushima. $\endgroup$
    – jamesqf
    Commented Feb 7, 2015 at 18:25
  • $\begingroup$ CME = Disable Satellites' Navigation and Propulsion Systems and nudge with Solar Wind = Falling Satellite? $\endgroup$
    – Malady
    Commented Feb 7, 2015 at 18:35
  • 2
    $\begingroup$ @Malandy: No, or at least not for many years. (Eventually drag from traces of atmosphere will bring down satellites in LEO.) Not only is the solar wind extremely tenuous, it acts in both directions on a satellite orbiting the Earth. That is, it slows the satellite while it is heading towards the sun, but speeds it back up when it's heading away. $\endgroup$
    – jamesqf
    Commented Feb 10, 2015 at 0:21

4 Answers 4


To go for maximal damage, you can combine flipping of magnetic poles, massive solar flare, and serious heat wave.

Immediate damage would be only to power grid, with no human casualties. But it will snowball from there:

Imagine 2006 Queens blackout in every major city in all over developed world. Huge amount of power-generating equipment is damaged or destroyed (fried), and if you are feeling nasty you can add failure of nuclear power stations, spewing radiation all over. Blow some chemical factories for diversity. You will be surprised how many are located close to dense populated areas like Indian Point, just 38 miles from NYC. So far you have radiation and no broadcasting (because broadcasting equipment was fried and has no power anyway. Guess what is next: huge panic.

In panic, people trying to escape to rural areas where is food. Well guess what: you cannot get gas at pump without electricity to pump it, and you have to pay cash. Yeah, this gets interesting. Because if you have a car I need, and I have a gun, after our meeting I have gun AND car and you have nothing. How far you can walk in heat wave (all water you can get is without sanitation) before you get some disease? Because there is no one to bring you clean bottled water. And if clean water is located somewhere, there is fight for it.

Civilization fell apart, it is mostly every man for himself. Heatstroke is dangerous killer even in normal circumstances. And these are not normal. People with children are most vulnerable to heat stroke - but there is hardly any help for them, everybody tries to save his own family, if s/he has any. So to escape, you have to walk far to your friends rural areas (if you are lucky enough to have any), in heat, with little water, and you have to hide before criminals who want to stole whatever you have in your backpack? How many people will make it? And of those who make it, how many are worst of criminal elements - and how many will be welcome in rural communities? Will they be willing work hard for food - or will they steal food from others?

Folks in rural areas did not liked those city dwellers anyway, and now worst of them (who made it far by stealing resources from others, less violent) want to come over and eat all the food and take over their communities? Fortunately rural folks have weapons. So small-scale civil war erupts. Such disruption make contagious diseases like cholera (caused by lack of sanitation and spoiled food) much worse. When supplies of normal trade are disrupted, many people with chronic conditions who rely on daily dose of life-saving medication will perish.

Finally, military control is established. But there is no way to feed all these people, even after 40% died from radiation, diseases, heat, crime, etc. Without steady supply of fertilizers, seed, fuel for farming machinery, productivity of farming decreases rapidly. Another source of decrease is former overspecialization. After collapse of markets, every area needs to produce all the food they need, not the one best suited for local microclimate. Cut down grapes, plow in strawberries, farm potatoes instead.

Another problem for farming is **genetically modified seeds. Some of them are sterile ** (cannot be used to grow next years crop, and you cannot buy new ones because someone ate them). Or if you are lucky seeds just do not bread true (so next generation is less productive, reverting to wild). Some seeds rely on herbicides which you cannot get. So farming slides back 200 years - but now you don't have plant varietes which farmers used 200 years ago.

So you cannot feed all population. You can either establish skill-based immigration to areas protected by military with some lottery for people without skills, if you feel generous, or make it free for all fight. Young and healthy, able to work, and with skills are desirable. Old, sick, no skills - no so much.

And yes, you will need to protect perimeters of your protected areas, but military is good at that.

Only now, when order was mostly restored, remnants of government can start figuring out what needs to be repaired, who can do it, and what is needed to repair it. Do you trust them to be smart and do right thing? Or waste time bickering and arguing about ridiculous irrelevant questions? Yes, now it looks much worse that month ago, and repairing it will take much longer. And hurricane season is just starting. Following by a freezing winter.

So coronal mass ejection by itself did not cause much damage. Damage was caused by our lack or preparation, and standard disruptions which accumulated on top of one another. Expect to lose 2/3rds of the population during the decade it will take to stabilize and rebuild.

So you have a break of a decade or two to recover and prepare for another blow: climate change. During this time, many children died because of lack of sanitation. Surviving children did not received much of schooling because they had to work to get food.

So general skills of your population is decreasing as skilled old-timers die off by age, or by accidents and simple diseases preventable and curable in previous times. So your less skilled, less educated, and less technologically advanced society is facing challenge which we don't know how to handle with our current advanced technology. As you can see, it is not going to get better any time soon. So you are forced to switch using less advanced technologies (because you don't have tools and skills to repair them if something goes wrong). Back to steam age, only now all the easy to access and mine resources are mined out.

Even if carbon output of human economies is much smaller, you use more carbon per unit of production - because carbon-based energy is all you have to feed all those people. So glaciers continue to melt, methane in permafrost continues to thaw, and climate continues to be disrupted. Southern areas, suffering less damage from sun flare, get more damage from desertification. As there is more energy in air from heat, summers get hotter and drier, winters wetter and colder, hurricanes worse, farming less predictable, famine more common. With ocean more acidic, food pyramid collapses (smallest zooplankton cannot form shell, so fish has less to eat) - only jellyfish and algae thrive.

Humans survive, but they look at the ruins of previous advanced civilization, repeating myths of survivors of the apocalypse and thinking: what went wrong? Why they did not prepared for emergencies like we do? Why they relied that someone else will help them? What they were thinking?


Coronal Mass Ejections Can Hurt Us

If you define the end of the world as losing our satellites, and knocking down power grids, then yes, the sun can totally do that! If not, I am afraid that a coronal mass ejection will not be the apocalypse you are looking for. Our magnetosphere is pretty robust. It will protect carbon-based life from getting fried, so coronal mass ejections will not end life on earth, just the way many humans enjoy going about it.

However, coronal mass ejections do have the chance to kill electronics, communications, and possibly even some infrastructures. We heavily rely on electronics, therefore removing those systems will hurt society. A massive coronal mass ejection aimed correctly has the potential to knock down systems people need to live and will affect those who do not need those systems to live.

Luckily, the sun seems pretty happy (if it had feelings) to shoot these ejections in whatever direction seems convenient. Due to this the odds of this particular event happening on earth is small. Probability is no guarantee against it, though, and given a large enough timescale, many events may happen.

Coronal Mass Ejections happen often enough that we should be concerned about it along many other things that can end the human race. NASA, as you seem to know, predicted that the odds of such an event happening during the next ten years is 12%. Infrastructure may need updating and improved protection, and vulnerable electronics will need backups or protection. We may even want to consider backup satellites or alternative means of communication (such as ham radio) in our preparations.

  • $\begingroup$ Thank you, PipperChip! Now I know what to do to my question to generate better answers! $\endgroup$
    – Malady
    Commented Feb 7, 2015 at 17:37

The earth is pretty safe from solar flares because of the magnetic fields that deflect the event around the earth. However, the magnetic poles switch occasionally, like every 600,000 years or so. We really do not know what happens when they do switch. We do not know if the magnetic field shuts down then restarts at the new polarity, or how long it takes the switch to happen.

So there could be a scenario were the magnetic poles are switching and the magnetic field shuts down for awhile, which would cause a catastrophic event on earth that would cause mass famine, break downs of society etc. it could take years to bring infrastructure back online. During this time human populations could decrease dramatically. I think the number people say that a sustainable number that could be supported after oil runs out is a billion people or less. During such an event oil would become very scarce, so farmers would not farm, and all those other things we depend on for day to day life, like Walmart would cease to function.

Since we really do not know what happens, or even if we loose or magnetic shield when the polarity shift happens, you can be pretty liberal with your conjecture about this in your story. If we lost the magnetic shielding of the earth, every solar event rather massive or not would effect us. In essence we would be in the solar wind constantly. The earth becoming something that resembles the planet mars would be the worst case scenario.

The death toll is completely variable. It could be one guy with a pace maker in Barrow Alaska falls dead in a large flare. It could be that the whole human race is wiped out if we lost our magnetic shielding that would change the planet so much that life would become unstainable. Some people believe that this is what happened on Mars. Apparently it may be possible that without a magnetic shield the solar wind scrapes the water off the surface of a planet after some time.

It is also conjectured that when the poles flip polarity that nothing too huge horrible things will happen. So I made an assumption that you needed to validate with a little information about solar flares the death toll with some plausible context. Whatever death toll you want to use can work. It is really not how big the solar flare is, it is how big the flare is and how strong the magnetic field is that determines how much damage there is to the planet and all the things on it.

So in your story line, just add the poles started flipping, and the magnetic field weakened to some point where x amount of damage happened and caused x amount of death. If your meaning is that you need to know how many healthy people standing outside could be zapped dead by the flare, the answer is zero. Unless of course the magnetic field turned off and they stood outside for a very long time, as the atmosphere was scraped away by the solar wind and they became more exposed to radiation and its deadly effects over time.

(They were outside for so long because the were in line for the new I-Phone 973, which is the same as the IPhone-972 except it had new magnetic shielding and was three times the price, and new improved apps of course.)

  • $\begingroup$ This is really nice! I could use this! ... What if I didn't want anything other than solar flares and their after-effects? $\endgroup$
    – Malady
    Commented Feb 8, 2015 at 0:32
  • $\begingroup$ @Malandy The device of the poles flipping, is feasible that you just make the magnetic shield weaken to some degree that fits the needs of your narrative. What exactly happens is unknown and very speculative. Mars lost its magnetic shield, and some say that is the reason the planet has no surface water now. The shield going away here for a few hours, days or whatever is possible, or just reducing in strength, fit what you need in. It is a very flexible premise. $\endgroup$
    – Jon
    Commented Feb 8, 2015 at 0:45
  • $\begingroup$ Yeah, I saw the flexibility too, it's not that it's not EXTREMELY useful for my apocalypse story... I'm just wondering what are the death limits of solar flares alone... $\endgroup$
    – Malady
    Commented Feb 8, 2015 at 1:08
  • $\begingroup$ @Malandy I do not believe that solar flares will kill anyone directly, it is the effects on technology failure that could lead to deaths. In a simple flare things like accidents or the failure of a vital piece of equipment in the OR. In a severe case, no heat, no fuel and the consequences, no medical service etc. $\endgroup$
    – Jon
    Commented Feb 8, 2015 at 1:18
  • $\begingroup$ I don't believe that solar flares can kill people directly either... Where are you getting that?? ... Oh! Where you said "Since we really do not know what happens" Did you mean that the death count due to solar flares could be almost anything I want because solar flares are so destructive, I could have any amount of destruction and societal collapse I want? $\endgroup$
    – Malady
    Commented Feb 8, 2015 at 1:50

As of this reply, the Earth's magnetosphere is weakening. There is a magnetic "hole" over the southern Atlantic which causes satellite blackouts. The anomalies in the strength of the magnetosphere are increasing in location and variability. A recent book attempts to somewhat explain this: https://www.goodreads.com/book/show/35754738-the-spinning-magnet

The pole flip event would take 100+ years and expose Earth to much more solar radiation than normal. The effect of any CMEs during this time would be vastly amplified.

This is a narrative fiction depiction of one author's thoughts on how a "double-tap" CME would destroy civilization: https://davecline.wordpress.com/2017/01/03/blue-across-the-sea-epilogue/

In it the destruction of digital money, the loss of all pharmaceutical production (most diabetics would probably die within 60 days). The cessation of fuel distillate production ( diesel, petrol, kerosene, etc.) The failure of distribution food channels and the hoarding aspect. The abandonment of cities. The mass-migration from one hemisphere to the other.

One feature not mentioned elsewhere is the potential for the plasma induced currents to overwhelm other long-line wire systems. Consider all wiring in buildings, home, ships. Consider all pipelines. All might be subject to induction currents resulting in overheating and terminal fire.

  • $\begingroup$ Welcome to WorldBuilding, Lexi Mize! If you have a moment please take the tour and visit the help center to learn more about the site. You may also find Worldbuilding Meta and The Sandbox (both of which require 5 rep to post on) useful. Have fun! $\endgroup$ Commented Jun 6, 2018 at 23:48

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