Millions of people could face protein deficiency if carbon dioxide levels continue to rise, researchers have claimed.
Under elevated concentrations of carbon dioxide (eCO2), the protein contents of rice, wheat, barley and potatoes fell by 7.6%, 7.8%, 14.1% and 6.4% respectively.
The impact of higher levels of eCO2 on C4 crops – like maize and sorghum – as well as legumes and pulses like peas, beans and chickpea, was smaller, said the experts from the Harvard T.H. Chan School of Public Health.
Given that 76% of the population derives most of their daily protein from plants the implications of further rises in levels of eCO2 could be severe. Based on current projections for eCO2, the team calculated that 1.57% of the world’s population (150 million people) could be at risk of protein deficiency by 2050.
“Anthropogenic CO2 emissions threaten the adequacy of protein intake worldwide,” the authors wrote in their paper for Environmental Health Perspectives. “Elevated atmospheric CO2 may widen the disparity in protein intake within countries, with plant-based diets being the most vulnerable.”
Samuel Myers, one of the report’s authors and senior research scientist at the Department of Environmental Health, said the findings highlight the need for countries that are most at risk to actively monitor their populations’ nutritional sufficiency, and, “more fundamentally, the need for countries to curb human-caused CO2 emissions”.