Nuclear weapons profoundly shaped the course of the last century. No other man-made creation has posed such a global threat than that of nuclear annihilation. Experts in politics and warfare alike give varying estimates from 1% to 25% chance of a nuclear bomb targeting a civilian location this decade. The Future of Humanity Institute (FHI) places the risk of “probability of complete human extinction by nuclear weapons at 1% within the century, the probability of 1 billion dead at 10% and the probability of 1 million dead at 30%.” J.F. Kennedy said the risk of nuclear war during the Cuban Missile Crisis was the equivalent of putting a bullet in a three-chambered revolver. Even if there have only been two nuclear detonations in the name of war, it does not diminish the immensely realistic fear that human life could be lost at the hands of nuclear war. We are not immune to repeating the nuclear past. We need to be sure that researchers are equipped well enough to mitigate the variety of nuclear scenarios which could occur.
Presently, we have an unprecedented number of high-yield warheads controlled by both stable and volatile nations. The total number of warheads has decreased since the 1960s, but the destructive power of our current weapons outcompetes old technology by miles. Of the 196 recognized sovereign states, thirteen possess nuclear weapons or have access to nuclear weapons. The United States and the Russian Federation hold the largest number of nuclear weapons. This is despite lowering their combined stockpile from 60,000 to 14,000 warheads over the last five decades. France, the UK, and China hold between two and three hundred warheads apiece. Pakistan and India have about 120 each. Israel and North Korea have unknown numbers of nuclear weapons. The rest of the list share the control and storage of another 150-250 in a nuclear sharing program, which brings the total number to roughly 16,000. With all these weapons in hand, nuclear war has several ways of potentially unfolding: by accident, on purpose, or because someone was being stupid (perhaps both of the former are included in this). Governments are run by people, people make mistakes and often it isn’t realized until it’s too late. The weightiness of nuclear war is that these mistakes are not on the scale of thousands of deaths, they’re on the scale of millions.
Although nuclear weapons have remained a hot topic politically and scientifically since their invention, many worry the attention given to them is not enough. Several organizations like the International Campaign to Abolish Nuclear Weapons have made it their mission to decrease nuclear stockpiles globally. Organizations like FHI, the Global Challenges Foundation, the Ploughshares Fund and others encourage people to engage with nuclear risk. They promote research into all stages of nuclear war: negotiations, policy making, decreasing stockpiles, and in the worst cases, preparing for the aftereffects of large-scale nuclear war. The main question is whether we are putting enough resources into studying nuclear risk, or if we’re gambling with human lives. After all, the consequences of nuclear war concern the whole of earth’s population, not just those in warzones.
In the 1980s, a group of scientists modeled the damage to our climate after a nuclear attack in what is known as the TTAPS study, named after the authors’ initials. Using methodology for modeling volcanic eruptions, they found that even a relatively small conflict with a total detonation of 100 megatons (Nagasaki was only 22 kilotons, but the largest warhead in existence today has a potential yield of 100 megatons) could cause subfreezing surface temperatures for months. This is a phenomena called nuclear winter. Regardless of where war would break out, the consequences of nuclear winter would disrupt food supplies globally and result in potentially millions of lives lost. A 2007 paper by Robock, Oman, and Stenchikov also revisited these models applying modern climate and arsenal input, but arrived at the same conclusion: the effects of nuclear war could still lead to nuclear winter. Modern arsenals may have fewer weapons than those in the mid 20th century, but modern weapons eclipse them by megatons of detonating power. Technological advances have made it possible to damage the climate more with fewer detonations, which means even a war between nations like Pakistan and India, with their limited stockpiles, could cause global devastation.
This grim forecast is not certain however; nuclear winter lacks precedence and is therefore difficult to study. Although the two nuclear strikes in Japan showed us the detrimental effects of radiation and the destructive capabilities of the warheads, the impact of those bombs would be small compared to the potential destruction caused by contemporary arsenals. After nuclear silos, the most likely targets for nuclear weapons are the towering metropolitan centers housing scores of people. Technological advancements in architecture and infrastructure have created a different environment compared to the cities targeted in the past, and thus there is a great need to model the damage to reflect these changes. The TTAPS and Robock studies, while important, have areas of uncertainty because their inputs were not based on the burning of cities.
Because cities have a diverse mix of materials, including plastics, petroleum, and other fuels, the type of smoke is much thicker and absorbent than smoke from a forest fire or volcano. It is not certain how much smoke or the ratios of smoke types that would result from burning a city, which points to a hole in the current literature. Along with the ash and dust, the vast amounts of nitrogen oxides from the blasts would likely deplete the ozone layer of the stratosphere even further, increasing the amount of UV radiation reaching the earth. Combined with the drastic cooling, the climate would be completely disrupted and as desolate as a frozen desert. Much like global warming, nuclear winter would be anthropomorphic climate change on a more drastic and astronomic scale.
Beyond this long-term climate change, at a human level nuclear winter would carry a steep cost to essential food supplies . We are almost entirely dependent on food sources that are not locally grown. Immediately after a nuclear event, transportation of food to nearby areas would be nearly impossible due to radiation and the destruction of infrastructure. If stored food was relied upon, there would likely not be enough to feed the affected population for more than a year. In the following months, temperature drops and rain disruption from the smoke and ash would obliterate essential growing seasons for the entire globe. Death from starvation would not be the only risk for survivors: absence of food on this scale is expected by some experts to lead to the crumbling of society as we know it.
The next steps facing humanity in the face of nuclear risk will be challenging. Both governments and the public need to be convinced that it is valuable to study and support the prevention/mitigation of nuclear war. It may seem obvious to some, but to others it feels far-off, distant, and much like the Boogie Monster you were warned about as a child; a tool meant to strike fear, not change. An impossibility. Constant impending doom is easy to ignore once we acclimatise to the narrative.
When experts discuss nuclear risk in terms of “chance” or “probability”, it becomes almost harder to grasp the severity. Humans are not very good at internalizing risk and probability, which means there is only a handful of people who understand the risk, and a smaller handful still of those who actually study nuclear risk. Cognitive biases, the handy mental cushions our brains setup to help us navigate the world, are often more of a hindrance. For example, it’s about 430,000 times more likely that you’ll die in a car collision than it is to win the lottery, yet people still play the lottery hoping to win, and people still get in their cars every morning and expect to keep living. Nuclear war may have not broken out yet even in the highest-tensioned settings, but lack of precedence does not negate threat.
There will always be a risk as long as there are weapons. The bright side of all of this is that it isn’t too late. The field of nuclear risk prevention and research could use additional capable minds. The best we can do as global citizens would be to use our voices to raise awareness, to participate in the democratic process if possible, to support the disarmament of nuclear weapons, and to hope our efforts win before someone makes the greatest mistake of this century.
Originally published in EuSci Magazine, issue number 21 (2017).