New study reveals over 5 billion people could die of hunger in a full-scale nuclear war between the US and Russia

Even a small war where two countries use nuclear weapons on each other could cause a worldwide food crisis, a new study warns. The soot from burning cities would cover the Earth, blocking sunlight and cooling the planet. This would lead to crop failures, and in the worst-case scenario, 5 billion people could be at risk of starving.

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

The study, published on 15 August in Nature Food, is the latest in a long series of studies about what could happen after a nuclear war. And right now, with the ongoing wars in Ukraine, Gaza, and tensions in other parts of the world, this study feels too close to reality. It’s terrifying to think that such a disaster could happen.

How It Would Happen

A nuclear war doesn’t just kill people with blasts, radiation, and pollution. It could affect everyone across the planet, even people far from the fighting. Xia and her team wanted to understand how a war would change the climate and how that would affect food around the world.

Today’s wars, especially Russia’s invasion of Ukraine, have already disrupted food supplies. With tensions rising in places like the Middle East, the fear of a bigger conflict turning into a global disaster is growing.

The researchers looked at different war scenarios and how they would affect the world’s climate. They studied how the soot from burning cities would cool the Earth, making it harder to grow food. In one scenario, a war between India and Pakistan could release between 5 million and 47 million tonnes of soot. A full-scale war between the US and Russia could release 150 million tonnes. This would stay in the air for years, making the world much colder and harder to survive in.

The Dire Consequences

Using data from the United Nations, Xia’s team looked at how much food people could grow after a nuclear war. They assumed people would try to grow crops for food instead of animals and would stop wasting food. But they also assumed that international trade would stop, as countries would need to focus on feeding their own people.

Even with these efforts, the numbers are shocking. In the smallest war scenario, like a conflict between India and Pakistan, food production could drop by 7% in the first five years. In a bigger conflict, the global food supply could drop by up to 50%. In the worst case, if the US and Russia went to war, food production could drop by 90% within just a few years.

Who Would Suffer the Most?

The countries hit hardest would be those with cooler climates, where crops already struggle to grow. The UK, for example, would face much worse food shortages than India. But countries like France, which produce a lot of food, might be able to feed their people even if trade stops.

Interestingly, Australia might be one of the least affected countries. Since wheat grows well in cooler temperatures, Australia could survive better than others. In the study’s maps, while most of the world is marked red, for starvation, Australia stays green. Xia laughs, recalling how her son looked at the map and said, “Let’s move to Australia.”

Scarier Future

This study is a step toward understanding the global food impacts of a nuclear war, says Deepak Ray, a researcher at the University of Minnesota. But it’s still not perfect. The world’s food system is complex, and the study can’t cover every little detail of how it would be affected.

Nuclear weapons are still a real threat, even though the Cold War ended long ago. There are still over 12,000 nuclear warheads in the world, and tensions are rising again. The chance of a nuclear war might seem far away, but with so many conflicts happening, it’s starting to feel closer than ever.

“It is rare to happen — but if it happens, it affects everyone,” says Ray. “These are dangerous things.”

The idea of a nuclear war might seem unlikely, but as we watch the world’s tensions grow, it’s clear that the risk is there. And if something were to happen, it would be a disaster like we’ve never seen before. It’s a terrifying thought that the chance of nuclear war is still out there, and it could destroy billions of lives. The time to act is now, before it’s too late.

doi: https://doi.org/10.1038/d41586-022-02219-4
Xia, L. et al. Nature Food https://doi.org/10.1038/s43016-022-00573-0 (2022).