India could be the country worst hit by the falling crop quality the world over due to rising carbon dioxide levels, according to a study led by the Harvard T H Chan School of Public Health.
The study estimates that 50 million more people in India — the largest number anywhere in the world — could face zinc, iron and protein deficiency due to dipping crop quality.
“The combined geographic impact across the three nutrients is concentrated in some of the poorest regions globally: India, other parts of South Asia, Sub-Saharan Africa, North Africa and the Middle East, and Southeast Asia. India alone is the largest contributor to all 3 nutritional vulnerabilities: 50 million additional people to the newly zinc-deficient population, 38 million newly protein deficient, and 502 million women of childbearing age and children under 5 who are vulnerable to disease resulting from increasing iron deficiency,” says the study, published in ‘Nature Climate Change’.
These worst-hit regions share a high reliance on elevated CO2-affected grains (for example, wheat and rice) and legumes for their supplies of major micronutrients, as well as a low intake of animal-sourced foods, the study points out.
It states: “India has shown inconsistent gains in addressing undernutrition and nutritional deficiencies. Despite significant progress in reducing the rate of underweight children since 1990, Indian children still have the fourth worst global weight-for-age scores (the standard measure for underweight), and nearly 35% of Indian children continue to meet the criteria for being underweight, far above the developing country average of 20%.”
According to National Family Health Survey-4, 38.4 per cent Indian children are stunted (low height for age), 21 per cent are wasted (low weight for height), 7.5 percent are severely wasted, and 35.7 per cent underweight.
“Our research makes it clear that decisions we are making every day — how we heat our homes, what we eat, how we move around, what we choose to purchase — are making our food less nutritious and imperiling the health of other populations and future generations,” said Sam Myers, lead author of the study and principal research scientist at Harvard Chan School.
Myers and his team analysed global health burden of CO2-related nutrient shifts in crops in 151 countries.
The study estimated that the world over, 175 million people could become zinc-deficient and 122 million protein-deficient by 2050 due to rising levels of carbon dioxide from human activity, which is making staple crops such as rice and wheat less nutritious. It also found that more than 1 billion women and children could lose a large amount of their dietary iron intake, putting them at increased risk of anemia and other diseases.
In general, humans tend to get a majority of key nutrients from plants: 63 per cent of dietary protein comes from vegetable sources, as well as 81 per cent of iron and 68 per cent zinc. It has been shown that higher atmospheric levels of CO2 result in less nutritious crop yields, with concentrations of protein, iron, and zinc being 3 per cent to 17 per cent lower when crops are grown in environments where CO2 concentrations are 550 parts per million (ppm), compared with crops grown under current atmospheric conditions, in which CO2 levels are just above 400 ppm.