HAVING MORE THAN 100 nuclear weapons in a nation’s arsenal could cause more harm than good for the country itself, according to a new study.

Researchers have said that while countries tend to believe that having access to more weapons is intimidating and makes other countries think twice before attacking them, using such weapons can destabilise the country itself.

The US and Russia, for example, each have thousands of nuclear weapons.

Joshua Pearce, professor at Michigan Technological University, and David Denkenberger, assistant professor at Tennessee State University and director of Alliance to Feed the Earth in Disasters (Allfed), co-authored an article published this week in the journal Safety.

Pearce and Denkenberger examined direct negative physical consequences of the use of nuclear weapons to the nation firing them, including impacts such as starvation and global supply chain disruption as well as the cost to maintain an extensive arsenal.

They found that a country willing to use nuclear weapons against another nation must determine whether it has the ability to survive the problems this will create.

There are nine nuclear-weaponised nations: the US, Russia, the UK, France, China, India, Pakistan, Israel and North Korea. There are approximately 15,000 nuclear weapons globally. Under the disarmament proposed in this research, this number would drop to 900 or fewer.

“With 100 nuclear weapons, you still get nuclear deterrence, but avoid the probable blowback from nuclear autumn that kills your own people,” Pearce said.

He added that defence expenditure post-9/11 shows that the US cares about “protecting Americans”.

If we use 1,000 nuclear warheads against an enemy and no one retaliates, we will see about 50 times more Americans die than did on 9/11 due to the after-effects of our own weapons.

Pearce said that this is the first study to quantitatively demonstrate just how dangerous the use of nuclear weapons is even for the aggressor nation.

During the week, North Korean denuclearisation was discussed at talks between leader Kim Jong-un and US President Donald Trump in Singapore.

After the meeting, US Secretary of State Mike Pompeo said Kim understands that denuclearisation must happen “quickly” in order for his country to get relief from sanctions.

Starvation and violence

In their research paper, Pearce and Denkenberger wrote: “No country should have more nuclear weapons than the number necessary for unacceptable levels of environmental blow-back on the nuclear power’s own country if they were used.”

The consequences of environmental blow-back include a significant drop in global temperature because of soot from nuclear blasts blocking the sunlight from reaching Earth’s surface, decreased precipitation, a drop in food production because of blocked sunlight and less moisture, increased ultraviolet radiation resulting from a badly damaged atmosphere, and non-functioning supply chains.

“We should be clear this analysis represents a severe underestimate on the number of dead Americans,” Pearce said.

We assume severe rationing, which is the best way to keep the most people alive when there is this level of food shortage. It means anyone who would die of starvation is immediately cut off from food.

“I don’t think rationing would go overly smoothly — a lot more people would die in violence internally than what we estimated based on lack of calories.”

100, 1,000 or 7,000 weapons

Pearce and Denkenberger examined the threat-potential of a 7,000-weapon arsenal, a 1,000-weapon arsenal and a 100-weapon arsenal.

Playing out a hypothetical scenario, the researchers explained that if the US used 100 nuclear weapons against China’s most populous cities, for example, initial blasts would likely kill more than 30 million people.

This would kill a higher fraction of the population than even severe pandemics. Sunlight would decrease by 10 to 20% and precipitation by 19% or more.

Pearce and Denkenberger, based on previous work, built a model of the burnable material in cities, how much would burn in a nuclear attack, how much of that would turn into smoke, and how much of that smoke would make it into the upper atmosphere.

Food supply

Then they used the result of climate and crop simulations to predict the impact on food supply. They coupled this with food storage to predict how many people would starve.

The agricultural loss from this so-called ‘nuclear autumn’ would range from 10-20%, enough to cause widespread food shortages in wealthier nations and mass starvation in poorer nations, researchers said.

Starvation could result because nuclear weapons would cause cities to burn, putting smoke into the upper atmosphere and blocking sunlight for years.

This could cause lower rainfall and lower temperatures, potentially causing winter-like weather in the summer, so-called ‘nuclear winter’. Less severe reduction in sunlight, which is called ‘nuclear autumn’, could still cause millions of people to starve.

It is clear that even 100 nuclear weapons is more than enough to dramatically reshape the globe, and Pearce and Denkenberger argue it’s also more than enough to deter other countries.

Maintaining more than that number, the authors state, is not only against the best interest of a nation to protect its people, but also costs a significant amount to maintain.

Denkenberger said the US government “should greatly increase focus on producing alternative food to provide for survivors in the case of nuclear war; with supply chains cut-off, all food Americans eat will have to come from within the nation’s borders”.

Pearse added that it’s “not rational to spend billions of dollars maintaining a nuclear arsenal that would destabilise your country if they were ever used”.

“Other countries are far worse off. Even if they fired off relatively few nuclear weapons and were not hit by any of them and did not suffer retaliation, North Korea or Israel would be committing national suicide,” he said.