Over the next 40 years, drought, erosion, and longer growing seasons brought on by climate change will radically alter the way food is produced all over the world. But until now, climate predictions failed to consider another factor in the future of key crops: Air pollution.
A new study from researchers at MIT and Colorado State University published in Nature Climate Change shows that ground-level ozone could exacerbate the effects of climate change on staple food crops like wheat, soybeans, maize, and rice. If global industry and governance fail to reduce emissions, researchers predict that crop production could dwindle by as much as 15%.
Researchers mapped out the tandem relationship between pollution and climate change in two scenarios. As a baseline, the MIT and Colorado State researchers estimate that climate change alone will result in a 11% decrease in global crop production. If countries fail to substantially curb greenhouse gas emissions (the first scenario), the scientists’ model shows that air pollution could trigger an additional 4% of crop failures. But if countries work to decrease greenhouse gas emissions after 2040, the researchers’ model shows that reduced air pollution could actually offset other negative impacts of warming on crops. They calculate that reduced air pollution in this second scenario could actually increase yields by 3%.
"This would counter some of the effect of climate change, and shows how air-quality management could benefit both human health and global food production," writes study co-author Colette Heald in an email to Co.Exist.
The link between air quality and food production may seem like odd, but the logic goes something like this: The atmosphere forms ozone when sunlight energizes pollutants generated from sources like cars and power plants. Ozone concentrations can also increase at higher temperatures, the kind that already wither temperature-sensitive crops like maize. On top of the heat, increased ozone levels attack pollution-sensitive crops, too—like wheat.
In the climate scenario where emissions decrease after 2040, the reduction in ozone alone would be enough to increase wheat production in the U.S. and China, the researchers say. Their findings show that reducing air pollution could slow the negative impacts of climate change—even enough to reverse some of them.
But some regions will be negatively impacted no matter what.
"It appears that South Asia will be the most hard-hit by the combination of warming and ozone trends, where ozone is expected to increase even in the more optimistic scenario," writes Amos Tai, one of the study’s co-authors, in an email. "African countries with low domestic production and heavily reliant on food imports are also expected to suffer more in terms of climate-pollution-driven food insecurity."