Are Increasing Levels of CO2 Causing Hidden Hunger

According to a recent commentary “Food Security: Fertilizing hidden hunger” by Müller C. and others published in Nature Climate Change, CO₂ fertilization and climate change will likely exacerbate macro and micro-nutrients deficiency in crops, jeopardizing one of the most important millennium development goals: to eradicate extreme poverty and hunger. This declining nutritional content could lead to “hidden hunger”– defined by the authors as an “insufficient supply of vitamins and minerals in diets with sufficient calorie content.”

The impacts of climate change on agriculture and food security are normally studied focusing on yields and calories. However, the authors claim that this scope may be misleading when analyzing the effect of CO₂ fertilization. In a changing climate, increasing CO₂ levels stimulate photosynthesis and plant growth (especially in essential crops like wheat, rice and soy), and reduce water consumption due to a more efficient use of nitrogen, compensating for some of the negative effects of climate change. However, Myers and others presented compelling evidence that higher levels of CO₂ will also negatively affect the nutritional value of important food crops, reducing concentrations of essential minerals (like Iron and Zinc) and proteins. This threat to the nutritional value of crops could have important implications for health and nutrition and should definitely be considered in future food security assessments.