The worst part of nuclear war is surviving it. Millions would die in a nuclear exchange between superpowers like Russia and the U.S., but billions more would die in the aftermath of even a “limited” nuclear war. That’s the takeaway from a new study published in Nature Food that models the effects of nuclear war on the global food supply.
The prediction is dire. “We estimate more than 2 billion people could die from nuclear war between India and Pakistan, and more than 5 billion could die from a war between the United States and Russia—underlining the importance of global cooperation in preventing nuclear war,” the study said.
The paper’s title is “Global food insecurity and famine from reduced crop, marine fishery and livestock production due to climate disruption from nuclear war soot injection” and it’s the latest work in the long-studied phenomenon of nuclear winter. The gist is that the massive explosion from nuclear bombs injects huge amounts of soot and debris into the atmosphere. The more explosions, the more soot and the more devastating the implications for the environment.
The soot injection from a nuclear explosion is comparable to that from volcanic eruptions, a naturally-occurring phenomenon that has disrupted climate systems and led to famines in the past. Alan Robock of Rutgers University is one of the paper’s authors and has a background in studying climate and the effects of volcanic eruptions.
In the 1980s, he learned about nuclear winter. “I calculated how climate would change using the same climate model I had been using for volcanic eruptions and I found, indeed, nuclear winter could last for a long time,” Robock told Motherboard. “I was amazed that [then-presidents] Reagan and Gorbachev listened to scientists from the United States and from Russia, who both got the same results that nuclear winter would happen after a nuclear war between two countries. That helped motivate them to end the nuclear arms race.”
The new study started by looking at what experts call a “limited nuclear war,” meaning a small-scale exchange of nukes. A detonation of 100 weapons would immediately kill 27 million people and starve ten times that number—260 million—by the end of the war’s second year. A worst-case scenario would be the detonation of 4,400 nuclear weapons, something that could happen if Russia and the U.S. engaged in a full-scale nuclear war. In that case, 360 million would die immediately and more than 5 billion would starve after two years.
“It doesn’t really matter what country has a war,” Robock said. “The amount of smoke would determine the climate change, and it doesn’t matter where because the smoke lasts for years. Once it gets into the stratosphere, it would cover the world.” Robock explained that there’s no rain in the stratosphere, and thus no way to wash away the nuclear smoke once it's settled there.
The resulting nuclear winter would cool the planet, kill wildlife, and disrupt agriculture on a grand scale. Those who survived the famine would still be starving. The models predicted that even limited nuclear war between countries with small nuclear arsenals like Pakistan and India, would have devastating consequences. As an International Physicians for the Prevention of Nuclear War analysis of the study said, “using less than 3% of the world’s nuclear weapons, a nuclear war between India and Pakistan could kill up to every 3rd person on earth.”
Despite the dire warnings and recent rise in nuclear anxiety, Robock is hopeful. He lived through the dark days of the Cold War and feels that tensions have eased and that cooler heads are currently prevailing. Yes, Russian President Putin has recently made nuclear threats and the U.S. is ratcheting up spending on nuclear weapons under the auspices of modernization, but Robock pointed to the current pushback from the international community and the revival of the Obama-era New START treaty—a treaty between Russia and the U.S. that limits deployed nuclear weapons and sets goals for reduction—as positive gains.
The UN recently ratified the Treaty on the Prohibition of Nuclear Weapons, an international ban on nukes. The problem, of course, is that the nine countries with the weapons haven’t signed it, and aren’t likely to. “It’s the will of the rest of the world to tell nuclear nations: ‘We don’t want nuclear weapons. We’re going to suffer if they’re ever used,’” Robock said. “There are no nuclear weapons in the Southern Hemisphere. So a lot of countries listen to what we do. But the nine countries that still have nuclear weapons have tried to ignore it. So the question is: How do you get them to listen?”
He also said he knows nukes aren’t high on some people’s list of priorities. “They’re worried about COVID or their job or education or healthcare and even global warming,” he said. “But nuclear war would be instant climate change. And it’s easy to solve the problem. Just get rid of the nuclear weapons and take them apart. We know how to do that.”