Nuclear bombs dropped on cities and industrial areas in a fight between India and Pakistan would start firestorms that would put massive amounts of smoke into the upper atmosphere.
The particles would remain there for years, blocking the sun, making the earth’s surface cold, dark and dry. Agricultural collapse and mass starvation could follow. Hence, global cooling could result from a regional war, not just a conflict between the U.S. and Russia.
Cooling scenarios are based on computer models. But observations of volcanic eruptions, forest fire smoke and other phenomena provide confidence that the models are correct.
Subscription required to view the rest of the article, but the science is rather sobering.