I posted this in the Philosophy room because there is a prevailing philosophy, if there is a major nuclear war all over the globe, that will spell the end of us and the end of civilization.
No it won't.
Here is why.
A. LAND MASS. Russia, Scandinavia, Canada, Australia, The US, South & Central America, and Africa all have gazillions of acres of uninhabited land. No nukes will even come close to any of it. The prevailing wind will also not cover much of it with fallout.
B. NOT EVERYONE TARGETED WILL DIE... There will always be survivors and those on the periphery who will live and rebuild.
C. ISLANDS....How many inhabited islands are there in the world ? How many UN-inhabited ones ? Unless they are targeted specifically, almost all of the islands and those living on them will be fine.
D. MOUNTAINS...several villages and some major cities of the world are right in the middle of mountain ranges. These will offer protection in the remote possibility they are targeted. Most will not.
E. SHIPS AT SEA...As of this very moment, at 0914 UTC time on 6/28/2021 there are exactly 255, 087 merchant ships at sea all over the world. Does anyone actually think those will also be targeted ? No they won't. They are also crewed with very skilled professionals of all trades, and additionally are carry those same good, like food, lumber, concrete, and steel as their cargo. This number DOES NOT include warships of various nations also at sea. Those people are equally as talented and skilled in their trades.
F. NOT EVERYONE HATES THE OTHER GUY...most people want to work together and get along. I have found this to be true in the 27 countries I have been to. Even the Communist countries I have been to were just fine on a people level. We have come close to nuclear war several times, but each and every time A HUMAN stepped in and stopped it. West Germany even awarded a Soviet officer a medal for doing so.
G. YOU CAN'T TARGET SUBMARINES.....and how many of them are skulking around under the layer depth ?
H. YOU CAN'T UN-INVENT TECHNOLOGY.....Once a technological achievement is made, it is here...period. There will also be skilled people to rebuild and get things back up and running. Nope, your scenario of stone tools and animal skins belongs back in the book you read. People will wear clothes, have jackets in the cold, cook on pots, and catch fish with rods, and hunt animals with firearms. They will clean those fish and animals with steel knives. Speaking of pot....I doubt any of the foolish laws we have now will matter much.
J. THOSE THAT SAY THEY WOULD NEVER WANT TO LIVE IN A POST-NUKE WORLD WILL ANYWAY....sounds like an emotional statement now, but when it happens, they will cling to life just like the rest opf us. Those that DO choose suicide will free up the gene pool for the stronger of us who will press on and ensure a holocaust like we experienced never happens again...EVER !!!
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Not one doomsday movie, TV show, or book takes any of this into account. They don't because they did not think their scenario through and if they did, they would realize everyone on the planet dying is completely wrong.
If you step away from the emotionalism and just look at a map of the world, you can easily see my point. It is a huge, huge world, and mankind's footprint on it is rather small.
There is just no way.
We humans are rather pesky, hard to eradicate, very resourceful, and adaptable.
...and we are also one of the few species that have sex for fun