Nagasaki before and after 1945 bombing. Photo: Public domain image.
Regional Nuclear War Could Trigger a 10-Year Nuclear WinterNuclear weapons are the gift that keeps on giving. We knew they were horrible from the very start (Hiroshima and Nagasaki -- historical trivia: Nagasaki's nuke was supposed to be dropped on Kokura, where the founder of Toyota was on that day), but over the following decades we kept discovering new reasons why they are bad: In the early 1980s, more and more studies showed that a nuclear winter was probable, and this probably helped cool down the cold war. More recently, a study showed that even a small regional nuclear war could create the mother of all ozone holes. But now we learn that even a small regional nuclear war could create our worst nightmare, a nuclear winter lasting about 10 years (!).
Photo: Public domain
Don't Think It Can't Happen, Because It Can
According to a study titled Climatic Consequences of Nuclear Conflict: Department of Environmental Sciences from Rutgers University, "A minor nuclear war with each country using 50 Hiroshima-sized atom bombs as airbursts on urban areas, could produce climate change unprecedented in recorded human history [...] New climate model simulations [...] show that the smoke would be lofted by solar heating to the upper stratosphere, where it would remain for years."
Even the smallest nuclear exchanges modeled show a plunge in temperatures that would be bigger than the Little Ice Age (approximately 1600-1850), but unlike other climate change events, the effects of a nuclear winter would be felt almost immediately (if the sun doesn't reach the ground anymore, it won't take long for temps to drop significantly).
Photo: Public domain
From Scientific American (bold is mine):
Twenty-five years ago international teams of scientists showed that a nuclear war between the U.S. and the Soviet Union could produce a "nuclear winter." ... killing plants worldwide and eliminating our food supply. ... International discussion about this prediction ... forced the leaders of the two superpowers to confront the possibility that their arms race endangered not just themselves but the entire human race. Countries large and small demanded disarmament. Nuclear winter became an important factor in ending the nuclear arms race. ... Gorbachev observed, "the knowledge of [nuclear winter] was a great stimulus ... to act."
Why discuss this topic now that the cold war has ended? Because as other nations continue to acquire nuclear weapons, smaller, regional nuclear wars could create a similar global catastrophe. New analyses reveal that a conflict between India and Pakistan, for example, in which 100 nuclear bombs were dropped ... would produce enough smoke to cripple global agriculture. ... Not only were the ideas of the 1980s correct but the effects would last for at least 10 years, much longer than previously thought. ...
More than 20 million people in the two countries could die from the blasts, fires and radioactivity. ... A nuclear war could trigger declines in yield nearly everywhere at once. ... Around one billion people worldwide who now live on marginal food supplies would be directly threatened with starvation by a nuclear war between India and Pakistan or between other regional nuclear powers.
George Mason University economist Robin Hanson asks this question over at Overcoming Bias: "So, the first news about nuclear winter was shocking enough to induce cold war adversaries to agree to big cuts. Today we know the situation is even worse - not only is nuclear winter easier than we thought to trigger, but more nations now have big enough arsenals to trigger it. Yet today there is far less international discussion or momentum to prevent such disaster. Why the difference?"
Nuclear DisarmamentNot that we needed more reasons, but this should help motivate everybody for more nuclear disarmament. It's folly to let the future of billions of people and whole ecosystems depend on a few people who control nuclear weapons (and the number of countries that have nukes has only gone up over time). We might think that a nuclear war can't happen, but history has shown us more than once that it almost did.
Now North-Korea claims to have nukes, Iran might them soon, Pakistan has them and isn't the most stable country, Israel has nukes and the US and Russian still have tons of them (and who knows how stable those countries will be in 10-20 years?). I really can't stress enough how important diminishing the risk of nuclear war is, even if by only a few percents (any difference in such a high impact event has a very high expected utility).
But Of Course...I want to make something clear: Our angle here at TreeHugger is to look at things from the environmental point of view. When it comes to nuclear war, there are many other very important aspects (obviously). Here I focused mostly on how we could screw up our planet and the ecosystems that support our lives and the lives of most other living creatures and plants, but the direct human cost of such a conflict could easily be in the tens of millions if not hundreds of millions (numbers so big that we experience scope insensitivity).
For more, check out Martin Hellman's risk analysis (he's the co-inventor of public key cryptography, without which the internet would be a very different place). He also has a site called Defusing the Nuclear Threat.
I also want to publicly support Obama's goal of reducing the number of nuclear warheads in the US and Russia.