Is carbon dioxide depleting crop protein?

Elevated levels of carbon dioxide inhibit plants' assimilation of nitrate into proteins, indicating that the nutritional quality of food crops is at risk as climate change intensifies.

Findings from a wheat field-test study were reported in the journal Nature Climate Change.

Protein concentrations in the grain of wheat, rice and barley -- as well as in potato tubers -- decline, on average, by approximately 8 percent under elevated levels of atmospheric carbon dioxide.

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.