One of the biggest challenges to reducing hunger and undernutrition around the world is to produce foods that provide not only enough calories but also make enough necessary nutrients widely available. New research finds that, over the next 30 years, climate change and increasing carbon dioxide (CO2) could significantly reduce the availability of critical nutrients such as protein, iron, and zinc, compared to a future without it. The total impacts of climate change shocks and elevated levels of CO2 in the atmosphere are estimated to reduce growth in global per capita nutrient availability of protein, iron, and zinc by 19.5%, 14.4%, and 14.6%, respectively.
The study, “A modeling approach combining elevated atmospheric CO2 effects on protein, iron and zinc availability with projected climate change impacts on global diets,” was co-authored by an international group of researchers and published in the peer-reviewed journal, Lancet Planetary Health. []— The study represents the most comprehensive synthesis of the impacts of elevated CO2 and climate change on the availability of nutrients in the global food supply to date.
While higher levels of CO2 can boost photosynthesis and growth in some plants, previous research has also found they reduce the concentration of key micronutrients in crops. The new study finds that wheat, rice, maize, barley, potatoes, soybeans, and vegetables are all projected to suffer nutrient losses of about 3% on average by 2050 due to elevated CO2 concentration.
Protein, iron, and zinc availability in wheat are projected to be reduced by up to 12% by 2050 in all regions. People will likely experience the largest decreases in protein availability from wheat in places where wheat consumption is particularly high, including the former Soviet Union, Middle East, North Africa, and eastern Europe.
In general, people in low- and middle-income countries receive a larger portion of their nutrients from plant-based sources, which tend to have lower bioavailability than animal-based sources. Nutrient reductions are projected to be particularly severe in South Asia, the Middle East, Africa South of the Sahara, North Africa, and the former Soviet Union — regions largely comprised of low- and middle-income countries where levels of undernutrition are generally higher and diets are more vulnerable to direct impacts of changes in temperature and precipitation triggered by climate change.
In South Asia, where the population’s iron intake already sits well below the recommended level-India exhibits the highest prevalence of anemia in the world — iron availability is projected to remain inadequate. What’s more, elevated carbon levels push the average availability of zinc in the region below the threshold of recommended nutrient intake.
— source ifpri.org International Food Policy Research Institute | Jul 18, 2019