Brazil’s O Globo examined how rising atmospheric CO₂ levels are reducing the nutritional quality of staple crops and worsening “hidden hunger” worldwide, particularly among vulnerable populations. The article cited research showing declines in essential micronutrients such as zinc, iron, and protein in major crops including rice and wheat, with disproportionate impacts in low-income countries that rely heavily on staple grains.
IFPRI senior scientist Timothy Sulser explained that elevated CO₂ causes plants to produce more carbohydrates without a proportional increase in mineral uptake, creating a so-called carbohydrate “dilution effect” that lowers nutrient concentrations in food crops. Sulser noted that the effects vary by crop, mineral, and location, and emphasized that additional plant processes affecting nutrient accumulation are also being disrupted, making the issue scientifically complex and in need of further research.
Sulser also stressed that while developing climate-resilient and nutrient-rich crop varieties will be important, adaptation alone will not be sufficient if greenhouse gas emissions continue to rise. He underscored that coordinated action across public and private agri-food institutions is needed to ensure improved crop varieties reach vulnerable populations, while ultimately warning that “the only way to avoid further negative effects from elevated CO₂ levels is to halt or reverse the current trajectory of emissions.”