More carbon dioxide (CO2) in the atmosphere is known to negatively impact the quality of food crops, but for the first time, a scientific study has been able to demonstrate how.
According to a press release, researchers at the University of California (UC) - Davis found CO2 adversely affects a plant's formation of nitrate into proteins. The study suggests that as climate change worsens, so will the quality of food crops. The researchers published their work in the journal Nature Climate Change.
"Food quality is declining under the rising levels of atmospheric carbon dioxide that we are experiencing," study lead author Arnold Bloom, a UC - Davis plant sciences professor, said in the release. "Several explanations for this decline have been put forward, but this is the first study to demonstrate that elevated carbon dioxide inhibits the conversion of nitrate into protein in a field-grown crop."
Nitrogen's processing into proteins is crucial in the growth of a plant because those proteins are vital to a healthy diet. For example, the proteins in wheat make up about one-fourth of a universal human diet.
To measure how CO2 affects wheat, the researchers examined sample from 1996-1997 and compared them to samples from today.
"These field results are consistent with findings from previous laboratory studies, which showed that there are several physiological mechanisms responsible for carbon dioxide's inhibition of nitrate assimilation in leaves," Bloom said.
He said more discouraging findings include an eight percent decline in proteins found in the grain of wheat, rice and barley when introduced to heightened levels of CO2.
"When this decline is factored into the respective portion of dietary protein that humans derive from these various crops, it becomes clear that the overall amount of protein available for human consumption may drop by about 3 percent as atmospheric carbon dioxide reaches the levels anticipated to occur during the next few decades," Bloom said.
