If CO2 levels continue to rise as projected, the populations of 18 countries may lose more than 5% of their dietary protein by 2050 due to a decline in the nutritional value of rice, wheat, and other staple crops, according to new findings from Harvard T.H. Chan School of Public Health.
Researchers estimate that roughly an additional 150 million people may be put at risk of protein deficiency because of higher levels of CO2 in the atmosphere. This is the first study to quantify this risk.
Impact of CO2 on plant protein
Globally, 76% of the population derives most of its daily protein from plants. To estimate the current and future risk of protein deficiency, the researchers combined data from experiments in which crops were exposed to high concentrations of CO2 with global dietary information from the United Nations and measures of income inequality and demographics.
They found that under higher concentrations of CO2, the protein contents of rice, wheat, barley and potatoes decreased by 7.6%, 7.8%, 14.1% and 6.4%, respectively.
India and Africa
The results suggest continuing challenges for Sub Saharan Africa, where millions already experience protein deficiency, and growing challenges for South Asian countries, including India, where rice and wheat supply a large portion of daily protein.
The researchers found that India may lose 5.3% of protein from a standard diet, putting a predicted 53 million people at new risk of protein deficiency.
‘This study highlights the need for countries that are most at risk to actively monitor their populations’ nutritional sufficiency, and, more fundamentally, the need for countries to curb human-caused CO2 emissions.’
Senior research scientist in the Department of Environmental Health