When we think about the war in Ukraine and the Nuclear threat it poses, next to a potential accident comes to mind Ukrainian nuclear power plant One scenario in particular comes to mind: The use of nuclear weapons.

We take a look at the bombings Hiroshimaand Nagasaki in 1945 – and what short-term and long-term health effects this had on the population. Experts use this knowledge to assess what would happen if nuclear weapons were used today.

Nuclear fallout depends on the type of bomb

After the dropping of an atomic bomb, what is known as nuclear fallout occurs. This consists of radioactive dust, which is hazardous to health.

How strong the nuclear fallout will be is difficult to predict. Because it depends on how and where a nuclear bomb is used.

“Weapons that explode at high altitude have different effects than weapons that explode on or in the ground,” said Dylan Spaulding, senior scientist at the Union of Concerned Scientists (UCS) Global Security Program.

“In the latter case, you have to worry about fallout because you’re basically radioactively activating the Earth,” said Spaulding. “In the case of an air explosion, on the other hand, you don’t necessarily have to worry about it the same way [radioaktiven Staub] make.”

Spaulding says different nuclear weapons can be deployed for different strategic reasons.

A mid-air explosion of a bomb can kill many people at once and has less long-term radiation effects on the surrounding population and environment.

In contrast, the detonation of a nuclear weapon close to the surface of the earth could not only kill many people at once, but also contaminate the environment and food supply for years.

This can be illustrated by the US bombing of Nagasaki and Hiroshima and the Chernobyl-Illustrate the 1986 accident in Ukraine. Within the following months, the attacks killed around 60,000 to 80,000 people in Nagasaki and 70,000 to 135,000 people in Hiroshima, even though the bombings released about 40 times less radiation into the environment than the Chernobyl accident.

Today, people can once again live safely in Nagasaki and Hiroshima without fear of prolonged radiation. But around the former Chernobyl nuclear power plant there is still an exclusion zone that is radioactive and uninhabitable.

Other effects of the 1945 bombing include an unusually high rise in leukemia cases among the surrounding people, especially children. Other types of cancer also increased, but to a lesser extent.

some studies showed the effects on children who were still in the womb at the time of the bombings. They had a smaller head circumference, grew more slowly, or had intellectual disabilities. Children conceived after the attacks had one investigation however, none of these consequential damages.

Nuclear weapons are potentially deadlier today

Weapons experts distinguish between tactical and strategic nuclear weapons.

Tactical weapons travel short distances and are designed to win battles. Strategic weapons, on the other hand, can travel longer distances and win entire wars.

The bombs used in Hiroshima and Nagasaki were considered strategic weapons – weapons that could win wars, not just individual battles.

However, Spaulding says that nuclear weapons have improved greatly in recent decades. So much so that some of today’s tactical nuclear weapons may be more powerful than the strategic ones used at the end of WWII.

“Many of the weapons in modern nuclear arsenals are far more powerful than those used in Hiroshima and Nagasaki,” says Spaulding. “They have up to 80 times more explosive power.”

So it’s difficult to take the bombings of Nagasaki and Hiroshima as a guide to what might happen today. But they can be a clue.

A lack of food could put billions of people at risk

However, there are attempts to simulate what the nuclear fallout might look like after today’s nuclear bomb attack.

Alex Wellerstein, a historian of science and nuclear weapons at the Stevens Institute of Technology in New Jersey, has one for that purpose Website called Nukemap developed. She compares the fallout from bombs detonating in the sky with that from bombs detonating on the ground.

In addition, in August 2022, a Study in the journal Nature Food released. The study authors predicted what would happen to the environment, population and the world’s food supply if Russia and the US engaged in a week-long nuclear war with strategic nuclear weapons.

The study’s authors estimated that there would be 360 ​​million direct casualties from the use of the weapons themselves. In addition, after such a nuclear war, more than five billion people would starve to death within two years – that’s about 60 percent of the world’s population.

The disruption to food supplies would be caused by massive amounts of soot from the fires that would result from the blasts.

The researchers also tried to model what the destruction would look like in other scenarios. As an example, they took a week-long nuclear war between India and Pakistan in 2025.

While its South Asian neighbors have far fewer nuclear weapons than the US and Russia, the authors still predicted around 164 million deaths. In addition, more than 2.5 billion people would starve to death within two years.

Hardly possible to stop a nuclear war once it has started

Alan Robock, Professor of Environmental Sciences at Rutgers University in the US, was one of the authors of the Nature study.

In previous research, Robock estimated that the bombing of Hiroshima and Nagasaki released about 500,000 tons of smoke. In the more recent study, he and his colleagues estimate that the US-Russia scenario would produce about 150 million tons of smoke and the India-Pakistan scenario would produce 16 to 47 million tons of smoke.

Robock says the study made predictions based on the impact of strategic weapons, “which simply means they’re coming from far away.”

“Any use of nuclear weapons can escalate into a full-scale nuclear war between NATO and Russia and would trigger a nuclear winter,” suspects Robock. Experts speak of a nuclear winter because the use of many nuclear weapons can darken and cool the earth’s atmosphere.

“There are not many ways to stop a nuclear war once it has started,” says Robock. “Panic, fear, miscommunication and misinformation can lead commanders to use the weapons they have.”

This article originally appeared in English.