A different view of climate change: Research claims rising temperatures may safeguard crop nutrition, but deplete yields

25 Jan 2019 --- The rapid onset of climate change and its potentially devastating impact on crops continues to be one of the most pressing themes of modern times. A multitude of studies have recently been published, all saying that extreme weather events will severely damage the agri-food supply chain and pose a risk to sustainably feeding the world’s growing population. But new research coming out of the US puts forward a different take on how climate change could impact crops.

A new study in Plant Journal from the University of Illinois, US Department of Agriculture Agricultural Research Service (USDA-ARS), and Donald Danforth Plant Science Center, suggests that hotter temperatures may offset the negative effects of higher carbon dioxide levels on seed quality.

Researchers carried out a two-year soybean field study where the crops were grown in real-world conditions and under heaters at the Soybean Free-Air Concentration Experiment (SoyFACE), an agricultural research facility in Illinois that is equipped to artificially increase carbon dioxide and temperature to futuristic levels.

Their seeds suggest that rising temperatures may actually improve nutritional content but decrease yields. 

Increasing temperatures by about 3°C may help preserve seed quality, offsetting the effects of carbon dioxide that make food less nutritious. In soybeans, elevated carbon dioxide levels decreased the amount of iron and zinc in the seed by about 8 to 9 percent, but increased temperatures had the opposite effect.

Trade-off between yield optimization and seed nutrition quality
Ivan Baxter Ph.D., Principal Investigator at the Donald Danforth Plant Science Center, Missouri, US, notes how iron and zinc are essential for both plant and human health. 

“Plants have multiple processes that affect the accumulation of these elements in the seeds and environmental factors can influence these processes in different ways, making it very hard to predict how our changing climate will affect our food.”

“This study shows that a trade-off between optimizing yields for global change and seed nutritional quality may exist,” adds co-principal investigator Carl Bernacchi, a scientist at the USDA-ARS, which funded the research along with the USDA National Institute of Food and Agriculture.

“It's a very controlled way of altering the growing environment of crops in agronomically relevant situations where the plants are planted and managed exactly like other fields in the Midwestern US,” Bernacchi adds. He is also an Assistant Professor of Plant Biology and Crop Sciences at Illinois' Carl R. Woese Institute for Genomic Biology.

FoodIngredientsFirst has requested more information from the research team. 

The research throws up questions about the “incomplete picture” of the complex environmental interactions that will affect crops in the future. 

It comes after some of the world’s leading science academies describe the current approach to food, nutrition, agriculture and the environment as being unsustainable and in need of urgent changes. Branding the global food system “broken,” collective action is desperately needed to turn around a multitude of failures, says an in-depth report from the InterAcademy Partnership (IAP). It calls for a total transformation of how systems operate as agriculture and consumer choices are major factors driving “disastrous climate change.”

In October, a leading body of experts, the Intergovernmental Panel on Climate Change (IPCC), issued its starkest warning yet on climate change. Limiting global warming to a rise of 1.5°C would require rapid, far-reaching and unprecedented changes in all aspects of society, according to its latest report.

With clear benefits to people and natural ecosystems, limiting global warming to 1.5°C compared to 2°C could go hand in hand with ensuring a more sustainable and equitable society, says the IPCC report, which followed three years of research. The study says that a rise of more than 1.5°C would risk the plant’s livability and this could be exceeded by 2030 unless drastic steps are taken now.