Governors' Biofuels Coalition

Climate change could drive malnutrition in more subtle ways than dry fields and heat-stricken crops.

Seemingly normal harvests actually deliver fewer nutrients when crops grow in a more carbon-dense atmosphere. That’s dire news for developing countries, where a decline in plant protein could tip millions into malnutrition.

More than three-quarters of the world’s people get most of their protein from plants. Some crops, like barley, tubers, wheat and rice, are more sensitive to changes in carbon dioxide. Countries with high poverty and high dependence on those crops face a double whammy.

It’s another example of how the people who contributed least to climate change are likely to suffer the most from it, said Samuel Myers, a Harvard University research scientist and an author of a new paper tracking the global repercussions of lower plant protein.

Diets low in protein can stunt growth, limit tissue repair, lead to low birth weights and cause wasting.

By 2050, climate change could cause an additional 148 million people to face the risk of protein deficiency, according to the study, published today in Environmental Health Perspectives. The other authors were Danielle Medek and Joel Schwartz.

That’s a 1.57 percent increase compared with the estimated 1.4 billion people who would face that risk under normal climate conditions. India would account for more than 1 in 3 of those newly vulnerable people.

Tajikistan, Bangladesh, Burundi, Liberia, the Palestinian territories, Iraq and Afghanistan would also see spikes in the number of people at risk, according to the research.

By and large, wealthy nations will be all right, Myers said. But people living in poor countries — where per-capita emissions have been low — have the least dietary flexibility to deal with less plant protein.

“Geographically, the people who are causing these CO2 emissions are different from the people who are vulnerable,” he said.

The decline in plant protein might be difficult to reverse through genetic engineering or selective cultivation.

The researchers estimate barley could produce about 14 percent less protein, wheat nearly 8 percent less and fruit almost 23 percent less.

“It’s a pretty big drop,” Myers said.

Legumes, sorghum and maize have proven resilient to higher CO2 levels, and the researchers encouraged wider adoption of those plants.

Those crops would do more to compensate for a protein gap than adding more fertilizers, which showed no effect on reversing protein declines, the researchers said. And supplementing diets with more meat is too resource-intensive and expensive.

Fertilizers and livestock also produce heavy amounts of greenhouse gases, compounding the underlying problem.

The researchers also stressed solutions outside the farmyard.

“More equitable food distribution, and poverty reduction measures should be a focus,” they wrote.

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