North Korea, Donald Trump and Nuclear Bombs: How Even a Minor War Would Be an Ecological Disaster for Earth

Castle Romeo nuclear test
The Castle Romeo nuclear test on Bikini Atoll, Marshall Islands, in 1954. United States Department of Energy

This article was originally published on The Conversation. Read the original article.

President Donald Trump's vow to hit North Korea with "fire and fury like the world has never seen" is an unveiled threat to unleash America's most potent weapons of mass destruction onto the Korean Peninsula. According to many defense analysts, the risk of nuclear confrontation over Europe and the Indian subcontinent also has increased in recent years.

In a more hopeful turn of events, 122 countries voted in June to adopt the United Nations Treaty on the prohibition of nuclear weapons in New York. The "ban treaty" will make nuclear weapons illegal for ratifying countries, and many see it as an opportunity to kick-start a renewed effort toward multilateral disarmament. Supporters of the treaty argue that even a limited, regional nuclear war would produce a catastrophic and global humanitarian crisis.

Trump kim Jong Un
North Korean leader Kim Jong Un and President Donald Trump. KCNA via Reuters/File Photo & Lucas Jackson/File Photo/Reuters

Equally, other analysts suggest that the reality is not as severe as is often depicted. In March of this year, Matthias Eken, a researcher of attitudes toward nuclear weapons, wrote in The Conversation that their destructive power "has been vastly exaggerated" and that one should avoid overusing "doomsday scenarios and apocalyptic language."

Eken argued that nuclear weapons are not as powerful as they are often described, on the basis that a nine-megaton thermonuclear warhead dropped over the state of Arkansas would destroy only 0.2 percent of the state's surface area. He also observed that more than 2,000 nuclear detonations have been made on the planet without having ended human civilization, and argued that if we want to mitigate the risk posed by nuclear weapons, we must not exaggerate those risks.

Eken's approach toward nuclear weapons stands in contrast to the more dramatic rhetoric of global humanitarian catastrophe and existential threats to humanity. So what is the basis for the latter?

Nuclear War Is Also a War on the Environment

The greatest concern derives from relatively new research that has modeled the indirect effects of nuclear detonations on the environment and climate. The most-studied scenario is a limited, regional nuclear war between India and Pakistan, involving 100 Hiroshima-sized warheads (small by modern standards) detonated mostly over urban areas. Many analysts suggest that this is a plausible scenario in the event of an all-out war between the two states, whose combined arsenals amount to more than 220 nuclear warheads.

In tats event, an estimated 20 million people could die within a week from the direct effects of the explosions, fires and local radiation. That alone is catastrophic—more deaths than in the entirety of World War I.

But nuclear explosions are also extremely likely to ignite fires over a large area, which coalesce and inject great volumes of soot and debris into the stratosphere. In the India-Pakistan scenario, up to 6.5 million tons of soot could be thrown into the upper atmosphere, blocking the sun and causing a significant drop in average surface temperature and precipitation across the globe, with effects that could last for more than a decade.

South African maize farmer
Farmers on land outside Lichtenburg, a maize-growing area in the North West province, South Africa, on November 26, 2015. Siphiwe Sibeko/Reuters

That ecological disruption would, in turn, badly affect global food production. According to one study, maize production in the U.S. (the world's largest producer) would decline by an average of 12 percent over 10 years in our given scenario. In China, middle-season rice would fall by 17 percent over a decade; maize by 16 percent; and winter wheat by 31 percent. With total world grain reserves amounting to less than 100 days of global consumption, such effects would place an estimated 2 billion people at risk of famine.

Although a nuclear conflict involving North Korea and the U.S. would be smaller, given Pyongyang's limited arsenal, many people would still die, and ecological damage would severely affect global public health for years. Additionally, any nuclear conflict between the U.S. and North Korea is likely to increase the risk of nuclear confrontation involving other states and other regions of the world.

It Gets Worse

A large-scale nuclear war between the U.S. and Russia would be far worse. Most Russian and U.S. weapons are 10 to 50 times stronger than the bombs that destroyed Hiroshima. In a war involving the use of the two nations' strategic nuclear weapons (those intended to be used away from battlefield, aimed at infrastructure or cities), some 150m tons of soot could be lofted into the upper atmosphere. That would reduce global temperatures by 8 degrees Celsius—the "nuclear winter" scenario. Under such conditions, food production would stop, and the vast majority of the human race would likely starve.

Vladimir Putin
“The crime that took the lives of dozens of civilians is shocking in its cruelty,” Putin said in a telegram sent to President Donald Trump. ALEXANDER ZEMLIANICHENKO/AFP/Getty

Eken suggests that a limited regional nuclear conflict and an all-out war between the U.S. and Russia are both unlikely. He may be right. However, both scenarios are possible, even if we can't reliably quantify the risk. Continued adversarial rhetoric from both Donald Trump and Kim Jong-un about the use of nuclear weapons is not making this possibility any less likely.

What we can say is that the doctrine of nuclear deterrence represents a high-risk gamble. Nuclear weapons do not keep us safe from acts of terrorism, nor can they be used to fight sea-level rise, extreme weather, ocean acidification, biodiversity loss or antimicrobial resistance.

This is why so many medical and public health organizations have been campaigning to make nuclear weapons illegal. Regardless of how many need to be exploded to cause a catastrophe or produce an existential threat to humanity, and regardless of the risk of it happening, the adage that "prevention is the best cure" remains the case when it comes to these abhorrent and dangerous weapons.

Research papers and discussions on the public health and environmental effects of nuclear weapons will be part of the Health Through Peace 2017 conference at the University of York in September.

David McCoy is professor of global public health at Queen Mary University of London.