This video details the catastrophic global consequences of even a "limited" regional nuclear war on the other side of the planet.
Recent peer-reviewed studies, done by atmospheric scientists Alan Robock (Rutgers), Brian Toon (University of Colorado-Boulder), Richard Turco (UCLA) and colleagues, predict that even a relatively "limited" nuclear war between India and Pakistan, in which each side uses 50 Hiroshima-sized nuclear weapons against the other's cities, could create immense firestorms that would quickly surround the planet with a dense stratospheric smoke layer.
The black smoke would be heated by the sun, lofted like a hot air balloon, and would remain in the stratosphere for years. There it would block and prevent a large fraction of sunlight from reaching the Earth’s surface. The sharp reduction of warming sunlight would reduce growing seasons would cause the starvation of up to 1 billion people.