Nuclear Darkness

5 million tons of smoke created by 100 Hiroshima-size nuclear weapons

Graph Scale
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)

  • War is fought with 100 Hiroshima-size weapons (currently available in India-Pakistan arsenals), which have half of 1 percent (0.05%) of the total explosive power of all currently operational and deployed U.S.-Russian nuclear weapons
  • 20 million people die from the direct effects of the weapons, which is equal to nearly half the number of people killed during World War II
  • Weapons detonated in the largest cities of India and Pakistan create massive firestorms which produce millions of tons of smoke
  • 1 to 5 million tons of smoke quickly rise 50 km above cloud level into the stratosphere
  • The smoke spreads around the world, forming a stratospheric smoke layer that blocks sunlight from reaching the surface of Earth
  • Within 10 days following the explosions, temperatures in the Northern Hemisphere would become colder than those experienced during the pre-industrial Little Ice Age
  • These nuclear war-induced effects on temperature would be twice as large as those which followed the largest volcanic eruption in the last 500 years, in 1816, which caused “The Year Without Summer”
  • This cold weather would also cause a 10% decline in average global rainfall and a large reduction in the Asian summer monsoon.
  • 25-40% of the protective ozone layer would be destroyed at the mid-latitudes, and 50-70% would be destroyed at northern high latitudes. Massive increases of harmful UV light would result, with significantly negative effects on human, animal and plant life.
  • These changes in global climate would cause significantly shortened growing seasons in the Northern Hemisphere for at least years. It would be too cold to grow wheat in most of Canada.
  • World grain stocks, which already are at historically low levels, would be completely depleted. Grain exporting nations would likely cease exports in order to meet their own food needs.
  • Some medical experts predict that ensuing food shortages would cause hundreds of millions of already hungry people, who now depend upon food imports, to starve to death during the years following the nuclear conflict.

Temperature changes in summer (°C) following a small nuclear war (India-Pakistan Conflict)

reduced temps after war with 5 million tons of smoke
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.