Rising CO2 levels threaten human nutrition

Rising CO2 levels threaten human nutrition

New study finds that as CO2 rises, iron and zinc levels fall in staple crops.

A new study published in the journal Nature found rising levels of CO2 in the atmosphere will directly reduce the nutrients found in many staple crops. Led by Dr. Sam Myers of the Harvard School of Public Health, the study analyzed nutrient concentrations of wheat, rice, maize, sorghum, soybeans and field peas. The results showed there is a significant decrease in zinc, iron and protein concentrations as CO2 levels rise to levels expected by mid-century.

The study is a meta-analysis of 143 different comparisons of the edible portions of six food crops grown in elevated CO2 conditions in seven different experiment locations in Japan, Australia and the U.S.

“By gathering data from seven locations across three continents for 41 cultivars of six crops, we were able to build a database that was more than an order of magnitude larger than all the previously published data combined, which gave us the power to prove the effect,” Myers said. “In the context of roughly 2 billion people already suffering zinc and/or iron deficiency and an estimated 63 million life years lost annually to these forms of malnutrition, reduced dietary access to these nutrients represents a very significant global health threat. We expect that tens or hundreds of millions of people will be placed at risk for zinc and/or iron deficiency as a result.”

The results were not uniform across all crops, and interestingly, even within crops different cultivars (strains of the crop) responded differently. This means that there may be an opportunity to breed these crops in order to adapt to CO2 increases, potentially life-saving news for those who will be placed at risk by this effect

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