Billions of people rely on wheat, rice, soybeans and peas for the majority of their zinc and iron intake. But as carbon dioxide increases, those minerals decrease, according to two studies published today in Nature and eLife.
Already a major health concern in the developing world, zinc and iron deficiency increases the risk of anemia, infections and even cognitive problems.
“This is yet another example of the impact climate change is already having on people’s ability to grow and access the nutritious food they need,” Hannah Stoddart, Oxfam’s head of policy for food and climate, told The Guardian. “With 25 million more children under 5 at risk of malnutrition by 2050 because of climate change, action to cut emissions and support communities to adapt is crucial.”
By the year 2050, researchers say, crops will have “significantly reduced concentrations of those nutrients.” And, as the mineral concentration decreases, starch and sugar appears to increase. That could exacerbate obesity problems around the world, the researchers warn.
“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,” said lead author of the Nature study Samuel Myers, a research scientist at the Harvard School of Public Health.
The researchers analyzed data involving 41 types of grains and legumes from seven areas of Japan, Australia and the United States. They found that wheat grown in high CO2 levels had 9 percent less zinc, 5 percent less iron — and 6 percent less protein. Not all crops were equally affected: maize and sorghum, which concentrate CO2 inside the cell for photosynthesis, didn’t experience the same decrease.
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