I think it’s necessary to inform people about some basic facts about nuclear war, from the position of a person “on the ground”, because we are no longer dealing with distant and general possibilities.
First of all, people assume they will know what’s going on. They assume they will be able to see nuclear explosions and mushroom clouds, and that they will be able to watch the news and know what’s going on. I find that exceedingly unlikely, and I’m afraid the most uncomfortable part of the nuclear war would be never knowing what actually happened, and having your horizon of information reduced from being able to connect to the Internet and gather information, or turning on the TV and watching the news, to not knowing anything beyond the reach of your immediate senses.
Let me explain why I think so.
First of all, a nuclear exchange is a limited thing even in the most extreme of versions. Nobody will try to nuke empty terrain or seas or mountains just for shits and giggles. Even in the extreme retaliation scenario, nukes will be aimed at the major cities. For a typical nuclear weapon, the visibility range of a nuclear mushroom, in the best-case visibility scenario, is around 400 kilometers. This means no mountains in between, clear skies, and a high vantage point. For most people, the vantage point is limited by terrain – tall buildings, trees, mountains and hills and so on. For instance, my vantage point is limited to several hundreds of meters on most sides, and then it’s trees and houses, and a hill to the North and East; to the South, I have a very narrow stripe through which I can see toward the center of Zagreb, but that’s basically 5° field of vision where I can see tens of kilometers in the distance. If a thermonuclear weapon doesn’t strike Zagreb, I don’t think there’s any chance I could see it. If it hits within a few hundred kilometers, a low rumbling sound could probably reach me, but I wouldn’t be able to tell what caused it – sonic boom, conventional explosion nearby or a nuclear explosion far away, because I have no experience with nuclear explosions. If a nuke went off in Split, I wouldn’t be able to tell, and that’s slightly over 200km away, air distance, but with a mountain range in between. The dust in the air in the aftermath would make the sky look very colorful in the sunsets, comparable to the aftermath of Mt. Pinatubo eruption, but it would take days to be able to tell with certainty that it isn’t just normal atmospheric conditions. Remember, you can’t rely on the Internet, or TV, or even radio – those things would go out in the very early stages of war, and even if you could pick up something on the radio, you need to understand that people broadcasting aren’t necessarily well informed either. They might be as ignorant as yourself, only with access to a radio station.
So, statistically you are either on the X, and thus really fucked, or you are far enough away to be completely in the dark as to what is going on. If you didn’t follow the news closely up to the very moment of the nuclear exchange, you will likely miss the fact that they actually did it.
Considering how the nuclear powers will concentrate primarily on each other in their exchange of strikes, a large part of the world would be both untargetted, and far enough from the targetted zones not to be able to tell what actually took place. There will be information blackout, there will be inability to reach any information from certain parts of the world, and those places will remain “dark” for the foreseeable future – no information will be coming from those areas, and nobody will be able to go in and personally verify and report back. There will be no journalists reporting over the satellite, there will be no Internet connection to the impacted areas. All the people who will actually be able to communicate via modern means will be those who are well outside the impacted areas, so far in fact that they will be completely in the dark as to what is going on. The world will be split into areas of death, and areas of ignorance.
There will be an increase in radiation, but most people don’t have a radiation detector so they wouldn’t be able to tell, or do anything about it. In any case, other than hunkering down during the first few weeks of the aftermath to avoid the worst of the radiation, there really isn’t much you could do. Later, avoiding things that have more radiation than others would be preferable, but I’m not sure that it would matter much for most people; the radiation would not be either the biggest danger or the biggest cause of death. You see, the reason why we have 8 billion people living on this planet, and why we had under a billion for most of history, are the modern agritechnical measures – the Haber-Bosch method of making fertilizer, diesel fuel that powers the agricultural machinery, great silos for storing wheat, and so on. No oil refineries, no diesel fuel. No gas, no fertilizer. No electricity, no refrigeration. No long-range transportation, no way of feeding people across large areas. If enough of that collapses, the world suddenly can no longer feed billions of people. Sanitary conditions will degrade. Medicine will degrade and people will die from all the things that killed them in the 19th century. Most people are trained to do things that will not matter in this new world, and are very poorly suited and trained to do things that will matter, which will be a strong evolutionary pressure. By this point, I hope to be long gone.