5 million tons of smoke created by 100 Hiroshima-size nuclear weapons
Following a war between India and Pakistan, in which 100 Hiroshima-size (15 kiloton) nuclear weapons are detonated in the large cities of these nations, 5 million tons of smoke is lofted high into the stratosphere and is quickly spread around the world. A smoke layer forms around both Hemispheres which will remain in place for many years to block sunlight from reaching the surface of the Earth. One year after the smoke injection there would be temperature drops of several degrees C within the grain-growing interiors of Eurasia and North America. There would be a corresponding shortening of growing seasons by up to 30 days and a 10% reduction in average global precipitation.
War with 100 low-yield nuclear weapons
Summary of Consequences of Regional nuclear war between India and Pakistan(from studies done at Rutgers, the University of Colorado-Boulder and UCLA)
Temperature changes in summer (°C) following a small nuclear war (India-Pakistan Conflict)
Reproduced/modified by permission of American Geophysical Union.
Surface air temperature changes following the injection of 5 million tons of smoke into the stratosphere after the detonation of a total of 100 Hiroshima-size nuclear weapons in the largest cities of India and Pakistan [for the 5 Tg standard case]. Temperatures are averaged for June, July, and August of the first year following the smoke injection. Effects are largest over land, but there is substantial cooling over tropical oceans, too. The warming over Antarctica is for a small area, is part of normal winter interannual variability, and is not significant.