Some politicians are toying with the existential threat of nuclear war as tensions between NATO and Russia, and the U.S. and North Korea, have reached new heights in 2023.
Dmitry Medvedev, the former Russian president and deputy chairman of Russia’s Security Council, warned on July 30 the country would use nuclear weapons if Ukraine succeeded in taking Russian territory as part of its counter-offensive.
North Korea’s defence minister made nuclear threats on July 20 in response to the U.S. deploying a nuclear-armed submarine to South Korea for the first time in decades.
As horrific as the nuclear blasts would be, it’s not necessarily the worst of it. Survivors would be hungry with no prospects of finding food and facing freezing temperatures. They would be living during the collapse of civilization, experts say.
A paper in Nature Food released last year demonstrated how a full-scale nuclear war between the U.S. and Russia could kill up to 5.4 billion people from nuclear winter-induced global famine. The paper also estimated a regional nuclear war between India and Pakistan could starve to death up to 2.8 billion people.
It was the first academic paper to quantify the death toll of a potential nuclear winter in detail.
These are staggering figures. By contrast, the Bubonic Plague killed between 75 million and 200 million people in the 13th Century. Yet these numbers are only the beginning of the story.
Nuclear Winter
The theory of nuclear winter was first developed in the early 1980s by scientists studying the atmosphere on Earth and other planets.
A nuclear explosion is like “bringing a piece of the sun down to the ground,” said O. Brian Toon, a climate scientist at the University of Colorado Boulder who worked on the first scientific paper on nuclear winter in 1983.
Fires start very easily in cities over which bombs are detonated. Hiroshima and Nagasaki had fires after the bombs exploded. These fires consume anything flammable over a large area, he said.
The smoke would only take “a few weeks” to spread over the hemisphere of the nuclear exchange and perhaps a couple of months to get into the other hemisphere, Toon said.
Then it would stay for years in the stratosphere, making it cold and dark and dry at the earth’s surface, said Alan Robock, a climate scientist at Rutgers University who has been studying nuclear winter since 1984.
“Smoke would rise up into the stratosphere, the layer above where we live, where there’s no rain to wash it out,” he said.
About “80 per cent” of sunlight would be lost in a full-scale nuclear war scenario between Russia, the U.S. and NATO, Toon said.
“There’s nothing mysterious about what happens next. It happens every day: the sun goes down, it gets to be night, it gets dark, it’s cold. It happens every winter,” he said.
With a U.S.-Russian nuclear war “there’d be enough smoke that temperatures would get below freezing, even in the summertime, in the areas where we grow our crops in the middle continents,” Robock said.
A 2007 paper by Robock and others found a global average surface cooling of 7 to 8 C persisting for years in this scenario. Even after a decade, the cooling is still expected to be about 4 C colder than before the war.
That is only the global average, mitigated by the vastness of the world’s oceans. On land, the average temperature over global crop regions is reduced by 16 C, the 2022 paper found.
For context, 20,000 years ago during the last ice age, global average surface temperatures were about 5 C cooler than at present. “This would be a climate change unprecedented in speed and amplitude in the history of the human race,” Robock wrote.
Famine
Lili Xia, a climate scientist who works with Robock at Rutgers University, along with Toon and others, modelled six nuclear war scenarios for the Nature Food paper: five between India and Pakistan involving different numbers of bombs with differing yields dropped on cities in both countries, and one involving a full-scale nuclear war between the U.S. and Russia.
In the largest India-Pakistan nuclear exchange, 47 million tonnes of soot are lofted into the stratosphere. This would result in a nearly 50 per cent decrease in global average calorie production, from major food crops, such as maize, rice, soybean and spring wheat, in years one to five after the war.
In a U.S.-Russia nuclear war scenario, 150 million tonnes of soot are lofted. Global crop production would decrease by around 90 per cent in the three to four years after the nuclear war.
To model this for each country, Xia used data from the Food and Agriculture Organization (FAO), looked at what crops are grown in the country and the nation’s diet, and assessed the impacts.
The models assumed all stored food would be used up and calculated how much food would be grown by year two, then divided that by the minimum number of calories to keep people alive, 1,911 per day, to assess the starvation death toll. Canada would be particularly hard hit since most of the country is already too cold for widespread agriculture, Robock said.
The worst effects are on countries at higher latitudes where “agriculture is marginal,” he said.
Canada would lose 99 per cent of calorie production from major crops and marine fish two years after a nuclear war between the U.S. and Russia—or even one between India and Pakistan. Unsurprisingly, this corresponds with 99 per centof Canadians starving to death.
“This paper looked at the effects over the first two years,” said Ira Helfand, the immediate past president of International Physicians for the Prevention of Nuclear War.
“But even if you’re not yet starving, but losing weight, if that continues indefinitely, you die. You can’t lose weight indefinitely,” he said.
When people starve, the body eventually “starts to devour itself,” said Matt Bivens, a full-time ER doctor, board member of Physicians for Social Responsibility and author of a scientific literature review on nuclear winter.
“It starts to break down your muscles and tissues in order to try and survive off of that,” he said. “You develop all sorts of electrolyte derangement and fluid shifts and you develop kidney and liver problems and you’re often bloated from fluid in your belly.
“With edema in your legs, even if you’re a young, healthy person, when you push on your legs, your fingers sink into your calves and legs because it’s just like a sponge,” Bivens said. “Then you get thinner and thinner and weaker and weaker and that’s that.”
Conflict
The models in the 2022 paper assumed all food would be distributed evenly within each country.
But Robock said that would be very unrealistic.
“You can imagine people who are wealthy and well-armed would keep enough food, and it would probably be much worse than that,” he said. “Predicting climate and food is hard enough. Predicting human behaviour, nonlinear interactions is much harder.”
The further toll in human suffering and death resulting from the social chaos because of global famine would probably be an “enormous” factor, Helfand said.
“People don’t just go into their homes and wait to die. They try to get access to what food is left. When your children are starving you do whatever you can to get food for them,” he said.
Bivens said when food gets scarce, people who are willing to be violent and are armed are going to get the food.
In the case of a smaller than full-scale nuclear war, there may not only be conflict over food between citizens, Bivens said.
It’s not safe to assume there would be a single nuclear war and the world would just live with the consequences, he said.
A smaller nuclear war could lead to a revenge nuclear war that one country wants to have against another. Or a “deranged group” could get a hold of weapons to attack another group, Bivens said.
“One of the consequences of a total breakdown of the entire international system will very likely be more nuclear wars,” he said.
Food
Finding food would be extremely difficult during nuclear winter, but survivors would need to find something to eat.
The foods being eaten would be “godawful,” Bivens said.
“You wouldn’t throw away the watermelon rind. You’d eat the watermelon rind,” he said. “You wouldn’t throw away the coffee grounds. You’d eat the coffee grounds.
“You wouldn’t eat the apple and throw away the core. You’d eat the core and the seeds and [it] still wouldn’t be enough,” Bivens said.
In historical famines, people begin by eating whatever is around including pets and animals that are not usually thought of as food sources, Helfand said.
In separate interviews, both Helfand and Bivens drew a comparison to the Siege of Leningrad in the Second World War to illustrate what life would be like for survivors of nuclear winter.
The blockade of Leningrad took place from September 1941 to January 1944, nearly two and half years, as the Nazis intentionally tried to starve the Soviets out of the city.
“People were peeling the wallpaper off the walls because the paste had a potato element to it that they could eat,” Bivens said. “They were eating their shoes and leather belts. They would boil them to make them soft. They were eating pine needles.”
So prolonged was the blockade and scarce was the food that people resorted to eating human flesh.
“After the cats and the dogs and the pigeons and the rats had been eaten, people did – not everyone obviously – but some people did engage in cannibalism,” Helfand said.
As horrible as the life inside Leningrad was, the hope existed that the city would eventually be relieved, Bivens said.
“Whereas when it becomes clear that your whole planet is out of food and no food is coming again for five to 10 years, if at all,” Bivens said. “You don’t even know if you’re ever getting out of this.”
As such, the public disorder would likely be worse than Leningrad because everything’s breaking down all around you, he said.
“I think there’s every reason to expect there would be cannibalism after a major nuclear war if there was anybody left to eat anybody else,” Bivens said.
Unmodeled
“Of course, there won’t be two billion survivors,” Toon said. The FOA data used for crop modelling was from 2010 when the global population was six billion, not the current eight billion, he explained.
This is just one of the seemingly countless ways in which the reality of nuclear winter would be far grimmer than the paper can detail. The calculations are about the second year after the war. But the lowest temperatures are not reached until the third year, Toon said.
The modelling “massively” underestimates the food situation because it only looks at the climate, Bivens said.
“They didn’t ask anything about what radiation does around the world. They didn’t ask anything about what happens when the ozone layer gets eroded and the sun is suddenly radioactively boiling the planet,” he said.
A 2021 paper published by the American Geophysical Union, led by Charles Bardeen, found nuclear winter would result in huge ozone losses.
The paper found there would be “a peak global ozone loss of 75 per cent with depletion lasting 15 years. Furthermore, “ozone loss leads to a tropical ultraviolet index above 35 after three years, lasting four years, and a 20 per cent global average UV-B increase.”
UV-B has more energy and is more biologically effective at creating damage, Thomas Tenkate, an expert on ultraviolet radiation exposure at Toronto Metropolitan University, said in an email to Humber News.
This would include skin cancers, and would dramatically change impacts on our vision, with a range of UV-related eye conditions becoming dominant, including various forms of cataracts, he said.
“These impacts would be significant because skin cancers are the leading type of cancer in the world (one in three cancers is a skin cancer) and cataract is the leading cause of blindness,” Tenkate said.
Radiation was also not included in the modelling.
“In fact, most of the radioactive contamination following a nuclear war would probably result from the melting down of power plants,” Helfand said.
The amount of radiation in nuclear power plants and the storage pools for spent fuel is “many, many, many times” the amount of radiation that is released by an atomic bomb itself, he said.
All these plants would melt down, certainly in the war zone, Helfand said.
“Depending on the full extent of societal collapse, many nuclear power plants and countries outside of the immediate war zone might also suffer catastrophic failures because the society around them would not be able to adequately maintain them,” he said.
It’s not clear what nuclear winter would do to insect populations. If the insect populations go down, the agriculture goes down, even if the climate is fine, Bivens said.
“The models say we’re looking at what happens when it gets this cold, for this long. That’s it,” he said.
“They’re not addressing what happens when all the butterflies are dead. I don’t know what happens when all the butterflies are dead. Maybe they’re all dead from the ozone or from the radiation or from the temperature,” Bivens said.
Xia, the lead author of the 2022 paper, pointed out that in their models, the authors assume that all industrial capacity, energy, and labour are still the same as before a nuclear war. But even without considering global cooling, the whole facility to support our modern life will be gone after a full-scale nuclear war, she said.
“I think our calculation from the Nature Food paper is already very optimistic,” she said.
Civilization
Nuclear winter may not be a species extinction event, Helfand said. But even if it’s not a species extinction event, it is a “civilization extinction” event, he said.
“It’s the Stone Age, but it’s the Stone Age in a world that’s been destroyed, that’s polluted, that’s denuded of its resources. It’s going to be much worse than the Stone Age,” Helfand said.
He said it was difficult even for him to imagine such a world.
“We look about our cities, we look about our hometowns, and we just can’t imagine that this can happen. I talk about this stuff all the time. I know this is what’s going to happen. I don’t believe it,” Helfand said.
“That’s a problem because that denial stands as a real barrier for me and for lots of other people in terms of doing all the things we need to do to make sure this doesn’t happen,” he said.
The Nature Food paper, detailing how 5.4 billion people could starve to death from nuclear winter is a “wild” underestimation of how awful it would be, Bivens said.
“And this could happen. This could all happen literally in an afternoon,” he said. “That’s the scariest part.”
James Westman 