Models predict that a veil of smoke from burning cities will surround Earth, triggering catastrophic crop failures.
According to new research, even a minor crisis in which two states use nuclear weapons against each other might result in global hunger. Soot from burning cities would surround the earth, cooling it by reflecting sunlight into space. This, in turn, would result in global crop failures, putting 5 billion people at risk of starvation in the worst-case scenario.
Lili Xia, a climate scientist at Rutgers University in New Brunswick, New Jersey, who conducted the study says, “a large percent of the people will be starving.”
The study, published in Nature Food1 on August 15, is the latest in a decades-long thought experiment regarding the worldwide consequences of nuclear war. It appears to be especially pertinent now, since Russia’s war against Ukraine has interrupted the global food supply, highlighting the far-reaching consequences of a regional conflict.
Nuclear war has a wide range of fatal consequences, from direct killing by atomic bombs to the long-term effects of radiation and other environmental degradation. Xia and her colleagues wanted to look into the impacts of war far from the battlefield, to see how people all across the world would suffer.
A nuclear war between India and Pakistan, maybe sparked by the disputed Kashmir area, might spew between 5 million and 47 million tonnes of soot into the atmosphere, depending on the number of warheads deployed and cities destroyed.
A full nuclear war between the US and Russia might generate 150 million tonnes of smoke. The encircling pall would last for years until the sky finally cleared.
Xia’s team calculated how declining crop yields and fishery catches after a nuclear war would affect the number of calories available for people to eat using data from the United Nations’ Food and Agriculture Organization. The researchers investigated several options, including whether people continued to raise livestock or whether they diverted some or all crops intended for livestock to humans instead. The study assumed that some biofuel crops would be repurposed for human consumption and that people would reduce or eliminate food waste. It was also assumed that international trade would halt as countries chose to feed their people rather than export food.
Xia points out that the analysis makes numerous assumptions and simplifies how the complex global food chain might respond to a nuclear war. However, the statistics are striking. Even in the simplest war scenario, a fight between India and Pakistan that results in 5 million tonnes of soot, global calorie production might reduce by 7% in the first five years after the war. Global average calories drop by up to 50% in a 47-million-tonnes-of-soot scenario. In the worst-case scenario of a US-Russia war, calorie production reduces by 90% three to four years after the conflict.
The nations most affected would be those in the mid to high latitudes, which already have a short growing season and would cool more significantly after a nuclear war than tropical regions. The United Kingdom, for example, will experience harsher declines in food availability than a country like India, which is located at lower latitudes. However, France, a large food exporter, would fare reasonably well – at least in the lower-emission scenarios – because if trade were suspended, it would have more food available for its people.
Australia is another less affected country. In the aftermath of a nuclear war, Australia would be cut off from trade, relying primarily on wheat for nourishment. And wheat would do well in the cooler temperatures caused by air pollution. Even in the direst war scenarios, Australia gleams an unspoiled green on the team’s map, which shows significant areas of the world colored red for starving. “The first time I showed my son the map, the first reaction he had is ‘let’s move to Australia,’” Xia says.
According to Deepak Ray, a food-security researcher at the University of Minnesota in Saint Paul, the study is a useful step toward understanding the global food implications of a localized nuclear war. More research, he argues, is needed to accurately recreate the complex mix of how crops are grown around the world.
Nuclear war may appear to be less of a concern than it was during the Cold War, but there are still nine countries with over 12,000 nuclear warheads. Understanding the probable repercussions of nuclear war in depth may aid nations in assessing the dangers.
Reference: Xia, L., Robock, A., Scherrer, K., Harrison, C. S., Bodirsky, B. L., Weindl, I., Jägermeyr, J., Bardeen, C. G., Toon, O. B., & Heneghan, R. (2022, August 15). Global food insecurity and famine from reduced crop, marine fishery and livestock production due to climate disruption from nuclear war soot injection – Nature Food. Nature; www.nature.com.