• “We must prevent a nuclear war from ever happening.”
  • About 75% of the world’s population would die from hunger following a nuclear war.
  • “No one has done this calculation before.”

As many as 5 billion people worldwide – 75% of the global population – would die from famine and hunger after a nuclear war between the U.S. and Russia, a new study says. 

The detonation of a nuclear weapon would cause massive fires and inject soot into the atmosphere, blocking sunlight from reaching the surface and limiting food production, leading to the deaths, the study said.

“A large percent of the people will be starving,” Lili Xia, a climate scientist at Rutgers University, who led the research, told Nature.com. “It’s really bad.”

Building on past research, scientists worked to calculate how much sun-blocking soot would enter the atmosphere from firestorms that would be ignited by the detonation of nuclear weapons.

“The reduced light, global cooling and likely trade restrictions after nuclear wars would be a global catastrophe for food security,” the study said.

‘We must prevent a nuclear war’

“The data tells us one thing: We must prevent a nuclear war from ever happening,” said Alan Robock, a professor of climate science at Rutgers University and co-author of the study.

Any nuclear weapon detonation that produces more than 5 teragrams (5 trillion grams) of soot is predicted to likely cause mass food shortages in almost all countries, the study said.

“In the extreme scenario the death toll will be the combined population of the United States, Europe, Russian Federation and allies and much more,” Deepak K. Ray told Newsweek magazine.

First-of-its-kind research

The research is the first of its kind, according to the study authors.

“No one has done this calculation before,” Robock told Health Day News. “No one has tried to calculate the numbers of people who would die.”

The study authors estimate that famine-induced deaths arising from a nuclear war between India and Pakistan could be in the region of 2.5 billion in the two years following the outbreak of war; for a nuclear conflict between the U.S. and Russia, famine-related deaths could reach 5 billion.

Nuclear war might seem less of a threat than it did during the Cold War, according to Nature.com, but there are still nine countries with more than 12,000 nuclear warheads among them.