How a small nuclear war would transform the entire planet (2020)

And Los Alamos is funded by a group that has a vested interest in keeping thier nukes, therefore downplaying the non-military, long lasting consequences.

On a similar note: "The Chernobyl explosion put 400 times more radioactive material into the Earth's atmosphere than the atomic bomb dropped on Hiroshima; atomic weapons tests conducted in the 1950s and 1960s all together are estimated to have put some 100 to 1,000 times more radioactive material into the atmosphere than the Chernobyl accident."

From: IEAE - Ten years after Chernobyl (https://inis.iaea.org/collection/NCLCollectionStore/_Public/...)

That interest is subtler than you make it out to be. The group wants to find out which catastrophes matter. It doesn't really mean that they are looking for one.

Think about it - how many cities have been destroyed by modern nuclear weapons from which they could draw conclusions?

Even the results of a simulation of such an event is highly speculative... what happens after the bomb depends greatly on the assumptions you make about damage to structures, weather patterns, the size of the bomb used, the altitude at which it is detonated, and a host of other variables.

The bottom line is that all we know for certain is that such an event would be horrific... but we don't know exactly how.

are there a lot of crops growing in the area between California and China. IIRC, there's a lot of ocean in that space.

Contrary to the US commanders' belief, the loss of civilian life was actually of little concern to Japan's military leadership. Several Japanese cities had already been destroyed to the same extent as Hiroshima and Nagasaki, at a greater loss of life outside than in those two cities combined. (That the bombs would continue to kill people for decades afterwards was not known at the time...)

What turned Japan to surrender was that simultaneously, the USSR was advancing rapidly in the (mostly undefended) north. USSR had taken Sakhalin and was very close to invading Hokkaido. The Japanese did not want any part of Japan-proper to be under Soviet rule, as that would have been devastating to their religion and culture. Surrendering to the US was seen as the lesser evil.

Small nuclear war = maybe 10 nuclear warheads explode. Life on most of earth continues more or less as "normal"

Large nuclear war = thousands of warheads, humanity is wiped out

There's a very big unknown here, which is how much soot a nuclear-induced conflagration of a city pumps into the stratosphere. We know that stratospheric soot would induce global cooling, for a time period of at least a few years, based on the observed effects of existing natural stratospheric soot pumps known as volcanoes. And we also know that without stratospheric pumping of soot, climatic effects are at best localized in both space and time (see, e.g., Kuwaiti oil well fires).

Personally, I am very unconvinced by the assertion that nuclear weapons causes severe global cooling. The most powerful volcanic eruptions in recorded history are VEI 6 or VEI 7, which means they erupted up to around 100 cubic kilometers of stuff. If you assume a city has an average height of 100 meters (for the sake of round numbers), you'd need a firestorm to completely consume 1000 square kilometers of city to produce the same volume of material. Furthermore, a volcano's eruptive column is a relatively narrow plume of ejection as opposed to a broadly dispersed firestorm base, so it seems that you'd have a far lower conversion rate of material into stratospheric soot--and correspondingly you'd need to burn even more area to achieve the same effect.

And at the end of the day, even the most severe volcanic winter in recorded history (1815) happening today would be roughly equivalent to rolling back global warming to 1850. For less than a decade.

I’d imagine it’s like filling a sink with water (and the drain slightly open) and use dye to simulate nuke debris. Try one or two drops every minute for ten minutes, vs. an entire cup of dye all at once.

Obviously the actual climate models are far more complex but for ELI5, I think this is the general idea.

We quickly realized this was a terrible idea(some tests in NV had intense fallout in NY) and stopped doing atmospheric tests by 1963.

I doubt this very, very much.

Also to note: those were single blasts (as opposed to the dozens that would now cover any given region), some were underwater, none of them interacted with amounts of structures and living matter comparable to a populated city.

And the wars kept getting deadlier as technology increased. During WW2, about 3% of the human species was killed using conventional weapons. But then in 1945 everything changed. Since we demonstrated the unwinnable situation that war against a nuclear power is, there have been exactly 0 unrestrained conflicts between nations with nuclear weapons.

So this formula is not so simple. Nukes are a catastrophe waiting to happen, but they are also the reason we've lived in this bubble of relative safety that is the only reality most of us have ever known. The promises and formalities of nations (as an optimist might like to declare the UN the reason such wars ended) are nothing new. The UN is a direct descendent of the League of Nations that formed following WW1 with the goal of ending such war, and there were similar organizations prior to the League. Nothing worked, until nukes.

Without nukes it seems likely that we would have almost certainly have long since seen WW3 and perhaps even more of its kin. One can only imagine what this would have translated to in terms of impact and our lives.

[1] - https://en.wikipedia.org/wiki/List_of_wars%3A_1500%E2%80%931...