If a nuclear exchange escalated, it could be. As few as a hundred or so nuclear explosions could kick up enough dust to significantly drop global temperatures for years. Even if the exchange was confined to middle east, the impact would be global.
There are alot of people fantasizing about nuclear war here, and it is important to douse them with a cold bucket of reality.
Nuclear winter is a myth, The US and USSR detonated literally thousands of nuclear weapons on its own soil in test towns. Both above ground and below. We never had problems with climate. The theory is flawed for several reasons.
1. It assumes modern cities will burn in firestorms, Maybe true for pre-WW2 wooden/brick structures, but flawed in modern times.
Cities are mostly built of steel and concrete, and wooden frame structures have significant fire code requirements to prevent uncontrolled burning.
Most skyscrapers burn from the material inside them, not the materials they're made with.
Just how building 7 in 9/11 collapsed after it was set on fire from large chunks of burning material from the towers, and then burned uncontrollably for 7 hours because water lines were cut from the collapse of tower 1.
2. It assumes the size of nuclear weapons are on the scale of volcanic eruptions, which are known to lower global temperatures. They are not even close in terms of size, The largest nukes in the US arsenal are adjustable 600 KT thermonuclear warheads. If you detonated all of them(3500-4500) you would certainly contaminate an environment for a long time, but not even close to the big volcanic climate changers.
3. Fallout requires ground burst weapons, an unlikely scenario as it is ineffective for damage. Most if not all will be airburst, with the fireball not likely to touch the ground. This will cause mass destruction, but will not heave much material into the mushroom cloud.
4. India and Pakistan have only around 170 warheads each, and none are particularly effective in size. with the largest tests being 40 Kt, or about the same as Hiroshima.
5. Pakistan has a "we'll use nukes if invaded", India has a "no first use policy".
6. None of their weapons are likely to be used against their neighbors, I.E. China. So while it will be devastating, it will be local and confined.
If you are afraid, read this book.
Nuclear Warfare Survival Skills.
It is free and written by a guy who wrote it while working at Oak Ridge for nuclear weapon assessment for survival. I attached both the 1999 and 2022 versions. Both are permissible to distribute.
https://en.wikipedia.org/wiki/Nuclear_War_Survival_Skills
Knowledge is a balm for fear.
