Nutrient Content of Staple Foods Diminishing from CO2 Concentrations

Credit goes to Tyler Wells Lynch for writing this article. 

Another Effect of Climate Change: Less Nutritious Crops

 By Tyler Wells Lynch 

Harvard researchers show that rising CO2 levels may reduce nutrient content in our staple foods.

Gluten-free lactose intolerant vegetarians may have a tough time getting their nutrients in coming years. Rising carbon dioxide levels in the atmosphere are expected to strip crops of vital mineral and protein content, posing yet another challenge to an already strained global food supply.

Harvard researchers conducted field trials with wheat, rice, maize, and soybeans, and found that levels of iron, zinc, and even protein were reduced after exposure to higher levels of CO2.

“This study is the first to resolve the question of whether rising CO2 concentrations—which have been increasing steadily since the Industrial Revolution—threaten human nutrition,” Samuel Myers, a research scientist from the Harvard School of Public Health, told the Harvard Gazette.

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Many of the developing world's staple crops are among those most likely to be nutrient-depleted due to rising CO2 levels. [Credit: Flickr user "iita-media-library" (CC BY-NC 2.0)] 

The study, which was published in the journal Nature, shows zinc concentrations in wheat decreased by 9.3 percent, while iron and protein levels dropped by 5.1 percent and 6.3 percent, respectively. 

In the developing world, iron and zinc deficiencies are already a public health concern.

According to researchers, roughly a third of the world population receives 70 percent or more of their dietary zinc and iron from the types of crops that are most likely to be affected by rising CO2 levels. In the developing world, these deficiencies are already a public health concern. 

The study analyzed nutrient content at CO2 levels of roughly 540 – 580 parts per million (ppm), which is significantly higher than current atmospheric levels of approximately 400 ppm. Climatologists do not expect carbon dioxide levels to reach that point for several decades, but the study nevertheless highlights the yet another concern about rising CO2 levels in the atmosphere.