"The effect of rising CO2 on our food quality is [one of] stealth – it's there, but our scientific radars are not tuned to it.

Iraki Loladze of the University of Nebraska-Lincoln, who predicted that rising CO2 would lead to smaller amounts of micronutrients in crops almost seven years ago (PDF), says he is concerned by the continuing lack of awareness of this problem: "The effect of rising CO2 on our food quality is [one of] stealth – it's there, but our scientific radars are not tuned to it.

SHOOT: Us humans are pretty bad when it comes to subtlety. We can't take a hint. We like movies about crunching metal and explosions - that's us.

clipped from www.newscientist.com 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. 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. "This study is important because it brings into sharp focus this effect on wheat – one of the largest sources of calories and nutrients for humans."