While our current administration lines the pockets of old men, the rest of the earth continues to heat up. Humanity is facing major obstacles as a result of our changing climate—by any metric. A new study of corn, the world’s most produced and most traded crop, says that the rising global temperatures of our changing climate may lead to a steeply increasing failure rate. Researchers out of Arizona State University published “Future warming increases probability of globally synchronized maize production shocks,” in which they analyze the chances of global corn-crop failures—a crop that most living things on our planet rely so heavily on.
We find that as the global mean temperature increases, absent changes in temperature variability or breeding gains in heat tolerance, the coefficient of variation (CV) of maize yields increases almost everywhere to values much larger than present-day values. This higher CV is due both to an increase in the SD of yields and a decrease in mean yields. For the top four maize-exporting countries, which account for 87% of global maize exports, the probability that they have simultaneous production losses greater than 10% in any given year is presently virtually zero, but it increases to 7% under 2 °C warming and 86% under 4 °C warming. Our results portend rising instability in global grain trade and international grain prices, affecting especially the ∼800 million people living in extreme poverty who are most vulnerable to food price spikes. They also underscore the urgency of investments in breeding for heat tolerance.
This study is obviously alarming, but in tandem with another new study analyzing the very similar effects climate change might have on vegetables, it is breathtaking. Other studies have supported the hope that increased carbon dioxide might boost vegetable and legume yields. But this new study explains that those wins will be greatly offset by the effects that decreased ozone and water scarcity would have in the same scenario. According to Inside Climate News, the decrease in these non-staple harvests could be as severe as 35 percent.