A new study published in Proceedings of the National Academy of Sciences combined empirical models of maize production with future warming scenarios to come up with a scary prediction: our warmer climate will mean lower and more variable maize yields.
The study comes from researchers at the University of Washington who were concerned by the impacts climate change could have on corn (maize). Corn is the most widely grown crop throughout the world; we eat it, we use it for oil, to feed our livestock, to fuel our vehicles. You’d be surprised about the number of products that depend on corn.
The researchers were interested in seeing how fluctuations in maize yields would impact the global market. They found that not only will a warming planet lead to decreased yields, it also ups the likelihood of simultaneous low yields across multiple high-producing regions, which could lead to price hikes and global shortages. Of the four countries that account for 87% of global maize exports (U.S., Brazil, Argentina and Ukraine), the chance right now that all regions would have a bad year together, with yields at least 10 percent below normal, is almost nonexistent. But that changes the more we heat up our planet.
The team found that with a 2 degrees Celsius warming, this risk increases to 7 percent; while with a 4 degrees Celsius warming, the risk jumps to an 86 percent chance that all four maize-exporting countries would simultaneously suffer a bad year. But why is that?
"When people think about climate change and food, they often initially think about drought," said lead author Michelle Tigchelaar, "but it's really extreme heat that's very detrimental for crops. Part of that is because plants grown at a higher temperature demand more water, but it's also that extreme heat itself negatively affects crucial stages in plant development, starting with the flowering stage and ending with the grain-filling stage."
This will undeniably have a large impact on the global economy. “Climate-induced shocks in grain production are a major contributor to global market volatility, which creates uncertainty for cereal farmers and agribusiness and reduces food access for poor consumers when production falls and prices spike,” write the authors. The solution? (Other than the obvious reduce-our-carbon-emissions plan.) The authors urge the industry to invest in breeding maize varieties that can better tolerate heat.