Why not a widespread nuclear conflict? Enough dust and particles would be thrown into the stratosphere to blot out the sun for DECADES, we have all that on good authority from the denizens of the Federation of American Scientists.
These brilliant scholars all have impeccable credentials so why should we NOT believe them?
Because saying it’s so does not make it so. It is all speculation, a bull session waiting to happen.
No need for a wide spread nuke war a single high yield device dropped into Yellowstone lake and sunk to the bottom will do the job of popping open the super volcanoes magma chamber. The ensuring that billions of cubic meters of dust , ash and particulates is shot into not only the stratosphere but past the kalman line into space. When the ash falls back north America would be covered in 3 to 100+ meters of ash and the sun would be dimmed to the point of freezing temps down to the tropics for decades if not a generation. Basically the worst parts of the Bible. ONE device in the right spot. The official report was marked secret and removed from circulation it’s a dang instruction manual for the end of humans. I’m a geologist it makes your hair stand on end when you realise just how easy it would be to wipe not only America off the map but every human in northern hemisphere in weeks due to ash in the lungs silicosis is 100% fatal, and the southern hemisphere in months as the planetary food web collapses