(CN) — In the 1930s, America experienced the Dust Bowl, an environmental and socioeconomic disaster that made matters worse during the Great Depression.
The Dust Bowl was an extreme and catastrophic event, and now due to the harmful effects of climate change, massive crop failures are more likely to happen again in the future, according to new research published Thursday in the journal Frontiers in Sustainable Food Systems.
The Dust Bowl was centered in the Great Plains because of the decades of unsustainable deep plowing becoming the new norm, displacing the native moisture-retaining grasses. This was followed by an atypical La Niña that then brought intense droughts, high temperatures and strong winds, which then blew away all topsoil in the form of large-scale dust storms.
This event directly impacted people, resulting in around 7,000 deaths and two million homeless, but the Dust Bowl also had a calamitous effect on crops where wheat and maize production plummeted by 36% and 48% during the 1930s.
The Intergovernmental Panel on Climate Change predicts that, in another three to four decades, most of the U.S. will further warm by 1.5-2 degrees Celsius (2.7-3.6 degrees Fahrenheit). This prediction includes issues that already exist today, where global food security is under pressure from the increased frequency of extreme weather events.
“We wanted to forecast how a multi-year production decline in a major exporting country, similar to that which occurred during the Dust Bowl, would affect modern food supplies globally via international trade,” said first author Alison Heslin, of the Center for Climate Systems Research of Columbia University and NASA’s Goddard Institute for Space Studies.
“In today’s system of global food trade, disruptions are not bound by borders. Shocks to production are expected to affect trade partners who depend on imports for their domestic food supply,” Heslin continued.
In the study, the authors developed two alternative computer simulations of the worldwide trade in wheat to assess the possible impacts a second dust bowl would have on this crop. They then added the extreme stimulus to these model systems in the form of a four-year-long dust bowl-like anomaly that would be restricted to the U.S.
Under the first simulation, countries would first use their reserves and then divide the absorbed shock between imports and exports, spreading it in one direction by increasing imports and in another by decreasing exports.
Under the much more complicated second model, the country would first reduce only its exports, spreading the shock to all receiving trade partners, which would then cause all countries with a shortage to respond by increasing their imports.
The results of the study, which were all estimated from historical data, predict a severity similar to that of the original event. According to the findings, the U.S. would fully exhaust 94% of its reserves over the first four years of an agricultural shock to the extent of a second Dust Bowl.
Both simulations also showed evidence that, without exception, all countries to which the U.S. exports wheat would decrease their reserves, even though they didn’t themselves suffer crop failure.
“We focused on a subset of the possible impacts, specifically changes in trade, drawing down strategic reserves and decreases in consumption,” said co-author Jessica Gephart, assistant professor at American University in Washington, D.C.
“We found that global wheat trade contracts and shifts toward other wheat exporters, and that wheat reserves around the world decline, in many cases to zero,” Gephart added. “This suggests that the impacts would not only raise prices for US consumers but would also raise prices far beyond the U.S. borders.”
Some of the key impacts that would follow a second four-year long dust bowl could include an initial 31% loss of global wheat stocks, which by the end of the four years would grow to 36-52 countries using up over 75% of their starting reserves.
The top 10 countries with the highest initial reserves — China, the U.S., India, Iran, Canada, Russia, Morocco, Australia, Egypt and Algeria — would see a decline in their reserves by 15-22% relative to the starting points.
There is, however, a silver lining in this harsh data. Due to the high initial starting point of global reserves, most supply shocks, even in countries without reserves, could be addressed through trade flow adjustments without reducing consumption.
“Our results remind us that mitigating climate risks requires accounting for not only the direct effects of climate change, like local extreme weather events, but also the climate impacts which travel through our interconnected system of global trade,” Heslin said. “In the context of food security, we show that accessing food reserves can, for a time, buffer populations from trade-induced supply shortages but as reserves deplete, people are at risk of food shortages.”