Eight nations now possess a nuclear arsenal; the US, Russia and China all have nuclear weapons big enough to precipitate a nuclear calamity, and a ninth, North Korea, now claims to have nuclear capability.
This prompted researchers and political scientists from the University of Nebraska Lincoln to revisit the question, based on a theoretical study of the effect of one hundred 15-kiloton warheads, with the explosive power of 150,000 tons of TNT.
Once exploded, such a strike would incinerate 1,300 square kilometres of a city and its surrounds. This would be quite enough to push five million metric tons of black carbon smoke particles into the stratosphere.
This would be enough to screen solar radiation, reduce the agricultural crop season by between 10 and 40 days a year for at least five years, and lower global temperatures to a point lower than normal for at least 25 years.
In the very short term, this cold snap would be colder than anything for the last 1,000 years. Rainfall would decrease by as much as 20% to 80% in the Asian monsoon region.
“Even a conflict that doesn’t involve the United States can impact us and people around the world”
The American southwest and western Australia could become 20% to 60% drier. South America and southern Africa, too, would see less rain. This global “nuclear drought” and the resulting famines “could kill up to a billion people from starvation.”
The most immediate victims would be those in countries that are already poor or food-insecure. And, the scientists warn, should a warhead fall upon a nuclear power facility “the spread of toxic radionuclides and their long-term effects would be greatly magnified.”
The drop in precipitation would, they warn, also increase conflict in developing regions, “although global temperature reduction may reduce social violence in the United States and other developed countries.”