Wheat nutrition declines as CO2 rises
By Nora Schultz You may have thought that the silver lining of rising carbon dioxide levels would be a boost in crop yields. But evidence is mounting that we may trade quantity for quality.
The discovery that staple crops like wheat have less protein when grown in high concentrations of CO2 has already caused concern, but the bad news doesn’t stop there. Ramping up CO2 also changes the balance of amino acids and several trace elements, says Petra Högy from the University of Hohenheim in Germany. Together with Andreas Fangmeier, also at the University of Hohenheim, and his team, Högy grew wheat in open fields over three years while blowing extra CO2 over the plots to achieve the concentrations of the gas that are expected to be reached by around 2050. They found several changes in the wheat grains, including an 8 per cent drop in iron and a 14 per cent increase in lead. “Both of these changes would be bad for human health. The drop in iron is particularly worrisome as half of the world’s population are already iron deficient, and this is going to get worse,” says Högy. …
