zlacker

The primary targets for nukes aren't cities, they're other nukes. Most of these warheads are set for groundburst (or underground burst - I remember a bunch of research in the 80s about burrowing/penetrating warheads), because to blow up a 3-4 foot thick reinforced concrete silo you basically need to land right on top of it. That's the big fallout threat.

>>nostra+(OP)
The nuclear winter theories I've read all involve the injection of soot into the stratosphere by nuclear-ignited firestorms. Buried nuclear blasts can dig pretty big holes (Sedan crater and all the other craters in the Nevada Test Site, which looks like the surface of the moon) and are certainly a huge fallout threat, but the claim of nuclear strikes against buried silos causing a nuclear winter is a new one to me.

Some napkin math: the Sedan test was optimized to dig a big hole, was buried almost 200 meters deep, and moved about 11 million tons of earth, leaving a crater of 0.005 cubic kilometers. The 1815 eruption of Mount Tambura, which caused a 'year without summer', ejected 160-213 cubic kilometers of material into the stratosphere, something like 32 thousand times as much as the Sedan blast. I'm guessing each strike against a nuclear silo would probably create craters a fraction the size of Sedan.

>>stretc+92
Since the concept of 32 thousand nukes exploding in a war sounded realistic (a bit on the "too many" side, but nothing completely impossible), I got into wikipedia to check if that was any particularly large bomb. I have bad news for you:

> The fusion-fission blast had a yield equivalent to 104 kilotons of TNT (435 terajoules)

That is a quite small fusion-fission bomb. If your calculation is right, we are talking about some hundreds of more normal ones, not tens of thousands.