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 climate change. 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.
“We’ve made a lot of progress reducing undernutrition around the world recently but global population growth over the next 30 years will require increasing the production of foods that provide sufficient nutrients,” explained Senior Scientist at the International Food Policy Research Institute (IFPRI) and study co-author Timothy Sulser. “These findings suggest that climate change could slow progress on improvements in global nutrition by simply making key nutrients less available than they would be without it”.
The study, “Combining the effects of increased atmospheric carbon dioxide on protein, iron, and zinc availability and projected climate change on global diets: a modelling study,” 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.
Improvements in technology, and markets effects are projected to increase nutrient availability over current levels by 2050, but these gains are substantially diminished by the negative impacts of rising concentrations of carbon dioxide.
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.
Severe in South Asia
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.
Researchers also emphasized the need for further work to build upon their findings, including additional study of climate impacts on animal sources, such as poultry, livestock, and fisheries, crops’ nutritional composition, nutrient deficiencies resulting from short-term climate shocks, and technologies that could mitigate reductions in nutrient availability.