New research indicates that a “regional”, limited nuclear war would have even more devastating global consequences than previously expected.

In addition to creating a global “nuclear haze” effect that would lead to global famine, a nuclear war involving as few as 100 Hiroshima-size nuclear bombs could cause serious depletion of the world’s ozone layer, leading to dangerous levels of ultraviolet radiation that would affect plants and animals around the world. (There are approximately 23,000 nuclear weapons, equivalent to more than 400,000 Hiroshima bombs, in the global arsenal.)

Even a nuclear war between India and Pakistan, which have much smaller arsenals than the United States and Russia, might be large enough to cause the predicted effects (“Nuclear War and Ultraviolet Radiation,” Staff Notes, National Center for Atmospheric Research, 2 March 2011):