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Climate Change and Rising CO2 Could Reduce Vital Nutrients Availability in Food

The production of foods that supply sufficient calories while making adequate essential nutrients extensively available is one of the biggest challenges to reducing hunger and undernutrition worldwide.

A new study has discovered that, for the next three decades, climate change and rising carbon dioxide (CO2) levels could considerably decrease the availability of vital nutrients like iron, protein, and zinc, when compared to a future without climate change.

The overall effects of climate change shocks and increased levels of CO2 in the atmosphere are expected to decrease growth in global per capita nutrient availability of iron, protein, 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. 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.

Timothy Sulser, Study Co-Author and Senior Scientist, International Food Policy Research Institute (IFPRI)

The paper titled “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 team of scientists and reported in Lancet Planetary Health, a peer-reviewed journal.

The research demonstrates the most comprehensive synthesis of the effects of increased CO2 and climate change on the availability of nutrients in the international food supply so far.

The scientists used the IMPACT global agriculture sector model together with data from the Global Expanded Nutrient Supply (GENuS) model and two data sets on the impacts of CO2 on nutrient content in crops to predict per capita availability of iron, zinc, and protein out to 2050.

Enhancements in technology and markets effects are estimated to raise nutrient availability over present levels by 2050, but these gains are significantly reduced by the adverse effects of increasing concentrations of CO2.

Although higher levels of CO2 can promote photosynthesis and growth in certain plants, earlier study has also identified that they decrease the concentration of important micronutrients in crops.

The new research finds that rice, wheat, barley, maize, soybeans, potatoes, and vegetables are all likely to suffer nutrient losses of approximately 3% on average by 2050 because of increased CO2 concentration.

However, the impacts are not likely to be experienced uniformly across the world, and it is also anticipated that several countries presently facing high levels of nutrient deficiency will be more affected by lower nutrient availability in the future.

Nutrient reductions are anticipated to be specifically severe in the Middle East, South Asia, North Africa, Africa South of the Sahara, and the former Soviet Union—areas largely covering low- and middle-income countries where levels of undernutrition are normally higher and diets are more susceptible to direct impacts of variations in temperature and precipitation induced by climate change.

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.

Robert Beach, Study Lead Author and Senior Economist and Fellow, RTI International

This implies that several people with already comparatively low nutrient intake will possibly become more susceptible to shortages in zinc, iron, and protein as crops lose their nutrients. Most of these areas are also the ones likely to stimulate the largest growth in populations and therefore requiring the most growth in nutrient availability.

The influence on individual crops can also affect diets and health unevenly. Substantial nutrient losses in wheat have particularly prevalent implications. “Wheat accounts for a large proportion of diets in many parts of the world, so any changes in its nutrient concentrations can have substantial impact on the micronutrients many people receive,” added Beach.

It is anticipated that the availability of iron, zinc, and protein in wheat will be decreased by up to 12% by 2050 in all areas. People will possibly face the most substantial reductions in protein availability from wheat in regions where wheat consumption is mainly high, including the Middle East, the former Soviet Union, Eastern Europe, and North Africa.

In South Asia, where the iron intake of the population is already well below the suggested level—India is found to have the highest prevalence of anemia in the world—iron availability is anticipated to remain insufficient. Furthermore, increased carbon levels move the average availability of zinc in the area below the threshold of recommended nutrient intake.

While the study’s models were restricted to 2050, Sulser added, “extending the analysis through the second half of this century, when climate change is expected to have even stronger impacts, would result in even greater reductions in nutrient availability.”

Scientists also stressed the need for additional work to build upon their findings, such as the further study of climate impacts on animal sources, like livestock, poultry, and fisheries; crops’ nutritional constitution, nutrient deficiencies due to short-term climate shocks; and technologies that could minimize reductions in nutrient availability.

Measuring the potential health impacts for individuals also necessitates a consideration of the several factors beyond food consumption—such as access to clean water, education, and sanitation—that impact nutrition and health outcomes.

Diets and human health are incredibly complex and difficult to predict, and by reducing the availability of critical nutrients, climate change will further complicate efforts to eliminate undernutrition worldwide.

Timothy Sulser, Study Co-Author and Senior Scientist, International Food Policy Research Institute (IFPRI)

This study was supported by the CGIAR Research Programs on Policies, Institutions, and Markets (PIM) and Climate Change, Agriculture and Food Security (CCAFS).


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