Climate change threatens crop nutrition, puts millions at risk

https://www.dw.com/en/climate-change-threatens-crop-nutrition-puts-millions-at-risk/a-45245760

Climate change threatens crop nutrition, puts millions at risk

Date 27.08.2018
Author Charli Shield

A new study estimates that hundreds of millions of people could be at risk of nutritional deficiencies because of rising levels of CO2 in the atmosphere, raising serious questions about the future of the developing world's health. The findings, published in the journal Nature Climate Change on Monday, have further revealed the extent to which climate change threatens our everyday nutrition. Researchers from the Harvard T.H. Chan School of Public Health estimate that unless carbon emissions are dramatically reduced in the coming decades, an additional 175 million people could be zinc deficient and 122 million protein deficient by 2050.

On top of this, 1.4 billion women of childbearing age and children under five could lose 4 percent of their dietary iron intake, putting them at risk of conditions like anemia.
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But there has been comparatively little research into the global health consequences of these findings. Using a GENuS (Global Expanded Nutrient Supply) database that estimates the health impact of lower nutrient intake for 151 different countries, the authors of this latest study examined which regions in the world will bear the brunt of staple crops like rice, wheat and potatoes losing their nutrients.

The biggest losers, as with most aspects of climate change, are "lower income countries," Samuel Myers, co-author of the study and director of the Planetary Health Alliance at Harvard, told DW.
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Staple crops like rice and wheat are the primary food source for more than 3 billion people around the world. Many who are unable to afford a diverse diet depend on these staple grains for most of their calories. It is these people, with "low dietary diversity" and "little animal source food" — often rich in iron zinc and protein — who will suffer the most from declining crop nutrition, Myers said.

The country expected to bear the biggest burden is India, which the researchers estimated would have an additional 50 million people deficient in zinc, 38 million protein deficient and 502 million women and children vulnerable to diseases associated with iron deficiency by midcentury.

Carbon dioxide is essential for plants to grow, but it is possible to have too much of it. While the science behind plant physiology is "complex," according to Myers, it is thought that higher concentrations of carbon dioxide can cause staple crops like wheat and rice to produce more carbohydrates, like starches and glucose, at the expense of nutrients, like protein, zinc and iron.
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